Performance of Biogenic Silica Photocatalytic Ceramic Foams and Cu-TiO2 NPs in the Degradation of Emerging Pollutants under Natural Solar Radiation

Yhosmary Franco; Jimmy Castillo; Juan C. Pereira

doi:10.21625/essd.v10i2.1168

Yhosmary Franco , Jimmy Castillo , Juan C. Pereira

https://doi.org/10.21625/essd.v10i2.1168

Issue
Vol. 10 Issue 2 (2025)

Submitted
January 8, 2025

Accepted
April 27, 2025

Published
June 24, 2025

Keywords:

Photocatalysis, Ceramic foam, Biogenic silica, Titanium dioxide, Emerging contaminants.

PDF XML

Abstract

Emerging contaminants in the drinking water supply are a growing concern due to their presence in various sources and incomplete degradation occurring in conventional treatment plants. This underscores the need to implement alternative and specialized processes for their removal. Photocatalysis, an advanced oxidation process that uses radiation as the sole energy source, is emerging as a promising solution. In this study, the performance of novel photocatalytic materials was evaluated: ceramic foams synthesized from biomass, specifically biogenic silica obtained from rice husk, and copper-decorated titanium dioxide nanoparticles (Cu-TiO₂ NPs). These foams were synthesized using the direct foaming method with CO₂, an efficient and sustainable approach. Their performance was evaluated in the degradation of acetaminophen (ACP), an emerging contaminant of pharmaceutical origin, achieving a removal of 91.0% with a loading of 1.5 g/L, a time of 83 minutes and using natural solar radiation. The results obtained demonstrate that these ceramic foams have the potential to overcome current limitations and represent a significant advance towards the implementation of photocatalysis on an industrial and global scale.

Full text article

Generated from XML file

References

Adamu, A., Isaacs, M., Boodhoo, K., & Abegão, F. R. (2023). Investigation of Cu/TiO2 synthesis methods and conditions for CO2 photocatalytic reduction via conversion of bicarbonate/carbonate to formate. Journal of CO2 Utilization, 70(January), 102428. https://doi.org/10.1016/j.jcou.2023.102428

Aguilar, C., De la Cruz, A., Montalvo, C., Ruiz, A., Oros, S., Figueroa, S., Abatal, M., Anguebes, F., & Córdova, V. (2022). Effect of kinetics on the photocatalytic degradation of acetaminophen and the distribution of major intermediate with anatase-Ag synthesized by sol-gel under visible irradiation. Frontiers in Environmental Science, 10(October), 1–11. https://doi.org/10.3389/fenvs.2022.943776

Borio, V., Vinha, R., Nicolau, R., De Oliveira, H., De Lima, C., & Silveira, L. (2012). Quantitative Evaluation of Acetaminophen in Oral Solutions by Dispersive Raman Spectroscopy for Quality Control. Spectroscopy: An International Journal, 27(4), 215–228. https://doi.org/10.1155/2012/108041

Cailletaud, J., De Bleye, C., Dumont, E., Sacré, P. Y., Netchacovitch, L., Gut, Y., Boiret, M., Ginot, Y. M., Hubert, P., & Ziemons, E. (2018). Critical review of surface-enhanced Raman spectroscopy applications in the pharmaceutical field. Journal of Pharmaceutical and Biomedical Analysis, 147, 458–472. https://doi.org/10.1016/j.jpba.2017.06.056

Cassano, A., & Alfano, O. (2000). Reaction engineering of suspended solid heterogeneous photocatalytic reactors. Catalysis Today, 58(2–3), 167–197. https://doi.org/10.1016/S0920-5861(00)00251-0

Castillo, J., Arcuri, M., Vargas, V., & Piscitelli, V. (2022). Synthesis of nanocomposites SiO2@Co3O4, SiO2@ZnO, and SiO2@CuO from rice husks: spectroscopy and optical properties. Applied Physics A, 128(2), 107. https://doi.org/10.1007/s00339-021-05247-5

De Bleye, C., Dumont, E., Rozet, E., Sacré, P. Y., Chavez, P. F., Netchacovitch, L., Piel, G., Hubert, P., & Ziemons, E. (2013). Determination of 4-aminophenol in a pharmaceutical formulation using surface enhanced Raman scattering: From development to method validation. Talanta, 116, 899–905. https://doi.org/10.1016/j.talanta.2013.07.084

Dorraj, M., Alizadeh, M., Sairi, N., Basirun, W., Goh, B., Woi, P., & Alias, Y. (2017). Enhanced visible radiation photocatalytic activity of copper-doped titanium oxide–zinc oxide heterojunction for methyl orange degradation. Applied Surface Science, 414, 251–261. https://doi.org/10.1016/j.apsusc.2017.04.045

Espiga, L. (2018). Materiales fotocatalíticos y sus aplicaciones en construcción [Universidad Politécnica de Catalunya]. In Universidad Politecnica de Catalunya. https://www.redalyc.org/pdf/115/11502906.pdf

Fernández, M., Matos, J., Montaña, R., Poon, P., Lanfredi, S., Praxedes, F., Hernández, J., Calvino, J., Rodríguez, E., Rodríguez, E., & Ania, C. (2019). Sunradiation photoactivity of rice husks-derived biogenic silica. Catalysis Today, 328(December), 125–135. https://doi.org/10.1016/j.cattod.2018.12.008

Fujishima, A., & Honda, K. (1972). Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature, 238, 37–38.

Gonzalez, K., Quesada, I., Aleksandrova, F., Julcour, C., Andriantsiferana, C., Manero, M., Albasi, C., & Jáuregui, U. (2016). DEGRADATION OF PARACETAMOL IN AQUEOUS SOLUTION: COMPARISON OF DIFFERENT UV INDUCED ADVANCED OXIDATION PROCESSES. Latin American Applied Research - An International Journal, 46(3), 115–120. https://doi.org/10.52292/j.laar.2016.341

Gupta, S., Gandhi, J., Kokate, S., Raikar, L., Gupta, V., & Prakash, H. (2023). Augmented photocatalytic degradation of Acetaminophen using hydrothermally treated g-C3N4 and persulfate under LED irradiation. Heliyon, 9(5), e16450. https://doi.org/10.1016/j.heliyon.2023.e16450

Hoerudin, Setyawan, N., Suismono, Purwaningsih, H., & Apriliani, N. (2022). Morphology, Extraction Yield, and Properties of Biogenic Silica Nanoparticles from Indonesian Rice Husk as Influenced by Solvent Type and Aging Time. IOP Conference Series: Earth and Environmental Science, 1024(1), 012076. https://doi.org/10.1088/1755-1315/1024/1/012076

Kaur, R., Kaur, A., Kaur, R., Singh, S., Bhatti, M., Umar, A., Baskoutas, S., & Kansal, S. (2021). Cu-BTC metal organic framework (MOF) derived Cu-doped TiO2 nanoparticles and their use as visible radiation active photocatalyst for the decomposition of ofloxacin (OFX) antibiotic and antibacterial activity. Advanced Powder Technology, 32(5), 1350–1361. https://doi.org/10.1016/j.apt.2021.02.037

Leong, C. Y., Teh, H. L., Chen, M. C., & Lee, S. L. (2022). Effect of Synthesis Methods on Properties of Copper Oxide Doped Titanium Dioxide Photocatalyst in Dye Photodegradation of Rhodamine B. Science and Technology Indonesia, 7(1), 91–97. https://doi.org/10.26554/sti.2022.7.1.91-97

Lin, J. C., Sopajaree, K., Jitjanesuwan, T., & Lu, M. (2018). Application of visible radiation on copper-doped titanium dioxide catalyzing degradation of chlorophenols. Separation and Purification Technology, 191(June 2017), 233–243. https://doi.org/10.1016/j.seppur.2017.09.027

Manga, I., Rao, S., Lakshmi, D., Chandra, R., Padmaja, S., & Divya, G. (2019). Poly 3-Thenoic acid sensitized, Copper doped anatase/brookite TiO2 nanohybrids for enhanced photocatalytic degradation of an organophosphorus pesticide. Journal of Environmental Chemical Engineering, 7(4), 103211. https://doi.org/10.1016/j.jece.2019.103211

Mojica, E., Zapata, J., Vedad, J., Desamero, R., & Dai, Z. (2018). Analysis of over-the-counter drugs using Raman spectroscopy. ACS Symposium Series, 1305, 69–91. https://doi.org/10.1021/bk-2018-1305.ch005

Moongraksathum, B., Shang, J.-Y., & Chen, Y.-W. (2018). Photocatalytic Antibacterial Effectiveness of Cu-Doped TiO2 Thin Film Prepared via the Peroxo Sol-Gel Method. Catalysts, 8(9), 352. https://doi.org/10.3390/catal8090352

Nevárez, M., Espinoza, P., Quiroz, F., & Ohtani, B. (2017). Fotocatálisis: inicio, actualidad y perspectivas a través del TiO2. Avances En Química, 12, 45–59.

Ochuma, I., Osibo, O., Fishwick, R., Pollington, S., Wagland, A., Wood, J., & Winterbottom, M. (2007). Three-phase photocatalysis using suspended titania and titania supported on a reticulated foam monolith for water purification. Catalysis Today, 128(1-2 SPEC. ISS.), 100–107. https://doi.org/10.1016/j.cattod.2007.05.015

Pereira, J., Castillo, J., & Labrador, H. (2023). Evaluación de las propiedades tribológicas y la viscosidad de un lubricante basado en un nanofluido de sílice ( SiO₂ ) Evaluation of the tribological properties and the viscosity of a lubricant based on a silica nanofluid ( SiO₂ ). Revista Ciencia e Ingenería, 44(December 2022), 79–88.

Porrang, S., Rahemi, N., Davaran, S., Mahdavi, M., & Hassanzadeh, B. (2021). Preparation and in-vitro evaluation of mesoporous biogenic silica nanoparticles obtained from rice and wheat husk as a biocompatible carrier for anti-cancer drug delivery. European Journal of Pharmaceutical Sciences, 163(April), 105866. https://doi.org/10.1016/j.ejps.2021.105866

Preda, S., Pandele-Cușu, J., Petrescu, S., Ciobanu, E., Petcu, G., Culiță, D., Apostol, N., Costescu, R., Raut, I., Constantin, M., & Predoană, L. (2022). Photocatalytic and Antibacterial Properties of Doped TiO2 Nanopowders Synthesized by Sol−Gel Method. Gels, 8(10), 673. https://doi.org/10.3390/gels8100673

Raheem, S., Sattar, J., & Al-Jubori, S. (2023). Characterization of Titanium dioxide (TiO2 ) Nanoparticles Biosynthesized using Leuconostoc spp. Isolated from Cow’s Raw Milk. Proceedings of the Pakistan Academy of Sciences: B. Life and Environmental Sciences, 60(1), 133–142. https://doi.org/10.53560/PPASB(60-1)823

Rodríguez, M., & Barrera, C. (2020). Procesos de oxidación avanzada en el tratamiento de agua. In Publicaciones UAEM (Primera ed, Vol. 1). Universidad Autónoma del Estado de México. http: //www.uaemex.mx

Shende, C., Smith, W., Brouillette, C., & Farquharson, S. (2014). Drug Stability Analysis by Raman Spectroscopy. Pharmaceutics, 6(4), 651–662. https://doi.org/10.3390/pharmaceutics6040651

Shrestha, D., Nayaju, T., Kandel, M. R., Pradhananga, R., Park, C., & Kim, C. (2023). Rice husk-derived mesoporous biogenic silica nanoparticles for gravity chromatography. Heliyon, 9(4), e15142. https://doi.org/10.1016/j.heliyon.2023.e15142

Srabovic, M., Huremovic, M., Catovic, B., & Muratovic, S. (2017). Design synthesis and crystallization of acetaminophen. Journal of Chemical , Biological and Physical Sciences, 7(January), 218–230.

Turkten, N., Cinar, Z., Tomruk, A., & Bekbolet, M. (2019). Copper-doped TiO2 photocatalysts: application to drinking water by humic matter degradation. Environmental Science and Pollution Research, 26(36), 36096–36106. https://doi.org/10.1007/s11356-019-04474-x

Ugarteburi, A. (2018). Optimizacion de la reologia de componentes Fotocataliticos para aplicaciones avanzadas en elementos de fachada [Universidad Politécnica de Catalunya]. http://upcommons.upc.edu/tesis

Warren, Z., Guaraldo, T., Martins, A., Wenk, J., & Mattia, D. (2023). Photocatalytic foams for water treatment: A systematic review and meta-analysis. Journal of Environmental Chemical Engineering, 11(1), 109238. https://doi.org/10.1016/j.jece.2022.109238

Yang, L., Yu, L., & Ray, M. (2008). Degradation of paracetamol in aqueous solutions by TiO2 photocatalysis. Water Research, 42(13), 3480–3488. https://doi.org/10.1016/j.watres.2008.04.023

Zhao, X., Wang, N., Zhu, M., Qiu, X., Sun, S., Liu, Y., Zhao, T., Yao, J., & Shan, G. (2022). Application of Transmission Raman Spectroscopy in Combination with Partial Least-Squares (PLS) for the Fast Quantification of Paracetamol. Molecules, 27(5). https://doi.org/10.3390/molecules27051707

Authors

Yhosmary Franco

PhD Candidate, Technological Chemistry, Experimental Faculty of Sciences and Technology, University of Carabobo, Valencia, Venezuela

[email protected] (Primary Contact)

Jimmy Castillo

Full Professor, School of Chemistry, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela

Juan C. Pereira

Full Professor, Department of Chemistry, Experimental Faculty of Sciences and Technology, University of Carabobo, Venezuela

Franco, Y., Castillo, J., & Pereira, J. C. (2025). Performance of Biogenic Silica Photocatalytic Ceramic Foams and Cu-TiO2 NPs in the Degradation of Emerging Pollutants under Natural Solar Radiation. Environmental Science & Sustainable Development, 10(2), 109–120. https://doi.org/10.21625/essd.v10i2.1168

Download Citation

This work is licensed under a Creative Commons Attribution 4.0 International License.

The Author shall grant to the Publisher and its agents the nonexclusive perpetual right and license to publish, archive, and make accessible the Work in whole or in part in all forms of media now or hereafter known under a Creative Commons Attribution 4.0 License or its equivalent, which, for the avoidance of doubt, allows others to copy, distribute, and transmit the Work under the following conditions:

Attribution: other users must attribute the Work in the manner specified by the author as indicated on the journal Web site;

With the understanding that the above condition can be waived with permission from the Author and that where the Work or any of its elements is in the public domain under applicable law, that status is in no way affected by the license.

The Author is able to enter into separate, additional contractual arrangements for the nonexclusive distribution of the journal's published version of the Work (e.g., post it to an institutional repository or publish it in a book), as long as there is provided in the document an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post online a pre-publication manuscript (but not the Publisher's final formatted PDF version of the Work) in institutional repositories or on their Websites prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (see The Effect of Open Access). Any such posting made before acceptance and publication of the Work shall be updated upon publication to include a reference to the Publisher-assigned DOI (Digital Object Identifier) and a link to the online abstract for the final published Work in the Journal.
Upon Publisher's request, the Author agrees to furnish promptly to Publisher, at the Author's own expense, written evidence of the permissions, licenses, and consents for use of third-party material included within the Work, except as determined by Publisher to be covered by the principles of Fair Use.
The Author represents and warrants that:

The Work is the Author's original work;
The Author has not transferred, and will not transfer, exclusive rights in the Work to any third party;
The Work is not pending review or under consideration by another publisher;
The Work has not previously been published;
The Work contains no misrepresentation or infringement of the Work or property of other authors or third parties; and
The Work contains no libel, invasion of privacy, or other unlawful matter.

The Author agrees to indemnify and hold Publisher harmless from Author's breach of the representations and warranties contained in Paragraph 7 above, as well as any claim or proceeding relating to Publisher's use and publication of any content contained in the Work, including third-party content.

This work is licensed under a Creative Commons Attribution 4.0 International License.

Received 2025-01-08
Accepted 2025-04-27
Published 2025-06-24

1. Introduction

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants present in water resources. ACP is an example of such contaminants and is found in prescription medications. Globally, about 1.4×105 tons/year of ACPs are consumed, indicating their potential impact on the environment (Gupta et al., 2023). Pharmaceutical contaminants can cause adverse health effects, such as aquatic toxicity and the development of resistance in pathogens. These compounds reach water bodies through various sources, such as direct disposal of surplus drugs, excretion by humans and animals, and inadequate treatment of manufacturing effluents (Yang et al., 2008).

Emerging contaminants are persistent due to their resistance to conventional wastewater treatments and are increasingly present in the environment. To significantly reduce the presence of pharmaceutical compounds in discharged effluents, additional treatments need to be implemented. Advanced oxidation processes (AOP) have proven to be effective for this purpose. AOP can be carried out as a tertiary treatment following biological (secondary) treatment, or as a pretreatment stage to improve the biodegradability of trace organic contaminants (Gonzalez et al., 2016).

Heterogeneous photocatalysis, an AOP, is based on the excitation of a solid, usually a wide energy gap semiconductor such as TiO₂, by irradiation whose energy is equal to or greater than its energy gap. This excitation causes the transition of an electron from the valence band (VB) to the conduction band (CB), generating photogenerated electron-hole pairs (e^-/h⁺) (Reaction 1). The holes (h+) can react with water molecules (H₂O) or hydroxyl groups (-OH) adsorbed on the surface, producing hydroxyl radicals (HO•) (Reactions 2 and 3), which have a high oxidative potential (approx. 1.7 mV) and are highly reactive with organic matter, resulting toxic to microorganisms (Reactions 10) (Fujishima & Honda, 1972). Furthermore, oxygen present in the air can function as a receptor for photogenerated electrons (e-) by reacting with them to form superoxide radical anions (•O_2-), which in turn react with water to produce hydroxyl radicals (Reactions 4 and 5). These reactions trigger a series of processes that contribute to the photocatalytic degradation of organic pollutants (Reactions 6 – 9) (Espiga, 2018).

TiO₂ + hv → TiO₂ (e^-_cb + h⁺_vb) (1)

h⁺_vb + H₂O → H⁺ + •OH (2)

h⁺_vb + ^-OH → •OH (3)

e^-_cb + O₂ → •O₂^- (4)

•O₂^- + H₂O → HO₂• + •OH (5)

HO₂• + H₂O → H₂O₂ + •OH (6)

e^-_cb + H₂O₂ → •OH + HO^- (7)

H₂O₂ + hv → 2HO• (8)

H₂O₂ + •O₂^- → •OH + HO^- + O₂ (9)

R / microorganism + •OH → Degradation products (10)

TiO₂ has characteristics such as being non-toxic, corrosion-resistant, biocompatible, low-cost, and with a high density of active sites (Nevárez et al., 2017). Despite its advantages, the use of TiO₂ as a photocatalyst has faced limitations due to its wide energy gap, which restricts its activation capacity under visible radiation. However, interest in using sunlight to activate photocatalysts has been increasing, due to its multiple advantages, such as its abundance, natural availability, and low cost (Rodríguez & Barrera, 2020). In this sense, research has been conducted to reduce the energy gap of TiO₂, to take full advantage of 43% of the solar irradiation spectrum. Among the main modifications are the implantation of metal ions, doping with metals and non-metals, among others. It has been observed that doping of TiO₂ with copper tends to increase the photocatalytic activity of the material under visible radiation, reducing the recombination of charge carriers (Kaur et al., 2021).

Photocatalysis has proven effective in removing organic micropollutants at the laboratory level, but its industrial application has been limited. Photocatalysts in the form of NPs dispersed in water or sludge have the drawback of requiring expensive removal processes to avoid leaching into water streams. On the other hand, immobilized catalysts have been developed to address this problem, although they have a smaller photocatalytic active surface area, which affects their efficiency. However, photocatalytic foams have the potential to overcome these limitations and move towards the industrial scalability of photocatalysis (Warren et al., 2023). Photocatalytic ceramic foams offer enormous potential in terms of efficiency, effectiveness, and most importantly, scalability. Materials with two different levels of porosity, microporous and macroporous, can efficiently convert irradiation into oxidative species that promote the degradation of micropollutants (Ochuma et al., 2007).

The purpose of this research was to analyze the performance of photocatalytic ceramic foams, synthesized from biogenic silica obtained from rice husks and pure TiO₂ NPs, as well as Cu-TiO₂ NPs, in the degradation of ACP using natural solar radiation.

2. Materials and Methods.

The research design used in this study corresponds to an experimental approach, in which experiments are conducted with rigorous control of the variables. These include concentration, pH, photocatalyst loading, and reaction conditions. This approach allows the effect of independent variables on dependent variables to be analyzed, using random assignment of treatments to ensure the validity of the results.

2.1. Chemicals

Commercial reagent-grade products were used without the need for added purification. Among the products used were TiO₂ anatase 99.5% from Sensient, sodium chloride (NaCl) 100.1% (MW= 58.44 g/mol) from Fisher Chemical, sodium hydroxide (NaOH) 96% (MW= 40.0 g/L) from Erba, copper (II) sulfate pentahydrate (CuSO₄·5H₂O) 99% (MW= 249.68 g/mol) from EMSURE, rice husks from Venezuelan crops (RH), phosphoric acid (H₃PO₄) 85% (MW= 97.994 g/mol) from Fisher Chemical, potassium hydroxide (KOH) 85% (MW= 56.11 g/mol) from Fisher Chemical, carbon dioxide (CO₂), monosodium phosphate (NaH₂PO₄·H₂O) 99% (MW= 137.99 g/mol) from Fisher Chemical, and paracetamol (C₈H₉NO₂) Lote: BP-03/11/08 from G. Amphray Laboratories.

2.2. Synthesis of ceramic foams

To synthesize ceramic foams, the following steps were followed: first, TiO₂ NPs were obtained by mechanical grinding of commercial TiO₂ with NaCl as an inorganic dispersant, using a Leegol Electric PG-LG-002 ball mill. Then, the wet impregnation method was used with 1% by weight of CuSO₄·5H₂O as a doping precursor, dissolving the CuSO₄·5H₂O in distilled water and mixing it with the TiO₂ NPs. The mixture was stirred at 50 °C for 2 hours (Faithful SH-2 hot plate), and the pH was adjusted to 8 with 1 M NaOH. Subsequently, it was dried at 90 °C for 24 hours, calcined at 450 °C for 2 hours and finally washed and dried again at 90 °C in a Raypa oven.

Biogenic silica was obtained from rice husk ash (RHA) following the protocol of (Castillo et al., 2022). This silica was dissolved in KOH and mixed with the TiO₂ NPs, subjecting it to ultrasound for 15 minutes with an Elmasonic E30H equipment. The mixture was bubbled with CO₂ and dried at 80 °C for 24 hours. In this way, two types of ceramic foam were produced: EC0 (with TiO₂ NPs) and EC1 (with Cu-TiO₂ NPs).

2.3. Characterization.

In the present study, tests were conducted to characterize the properties of the synthesized TiO₂ NPs, as well as those of the ceramic foams. For this purpose, the X-ray diffraction (XRD) technique was used to determine both the crystalline structure and the size of the TiO₂ crystals. The analysis was performed using a D2 PHASER XRD Bruker equipment, belonging to the Institute of Advanced Studies Foundation (IDEA). This equipment operated at 30 kV and 10 mA, using Cu Kα radiation. The sensor was scanned in a 2θ angle range of 10° to 70°, with a step size of 0.02° and a time per step of 1 second. In addition, a wavelength of 1.541840 Å and an incidence window of 0.2 mm were used. These experimental conditions allowed precise data to be obtained for the structural and morphological characterization of the analyzed samples.

From the broadening of the peak corresponding to the anatase phase (101), the average size of the crystals of both the TiO₂ and Cu-TiO₂ NPs was estimated, applying the Scherrer equation (Equation 1) (Moongraksathum et al., 2018):

\documentclass{article} \usepackage{amsmath} \begin{document} \displaystyle L = \frac{0,9\lambda}{\text{βcosθ}} \end{document} (1)

In the formula given, L is the average crystallite size, λ is the X-ray wavelength (0.154184 nm), β refers to the full width at half maximum (FWHM) in radians, and θ is the diffraction angle.

On the other hand, the ceramic foams were analyzed by XRD using a LANScientific Fringe Class 65410034 equipment, belonging to the School of Geology and Mines of the Faculty of Engineering of the Central University of Venezuela (UCV). This analysis was conducted under a configuration of 30 kV and 16 mA, using Cu Kα radiation with a wavelength of 1.54060 Å. Additionally, morphological characterization and elemental analysis were conducted by scanning electron microscopy (SEM) and X-ray dispersive spectroscopy (EDS). For this, a JEOL JSM-6390 equipment was used, equipped with an Oxford Instruments model 7582 X-ray detector, belonging to the Simón Bolívar University (USB).

2.4. Evaluation of photocatalytic activity.

The photocatalysis experiments were conducted under natural solar radiation during sunny days in the months of August, September, and October of the year 2024. The initial total radiation recorded was 924 W/m², measured with a digital radiometer. These tests were conducted at the School of Chemistry of the Faculty of Sciences of the UCV, located at the geographic coordinates 10.487348333689186, -66.8958709428127. The experimental system (Figure 1) consisted of a cylindrical borosilicate reactor operated in batch mode, with a volume of 200 mL of ACP solution and a ceramic foam loading of 1.5 g/L. The reactor operated under constant magnetic stirring and with continuous oxygen injection from a continuous air flow of 8.33×10⁻⁶ m³/s, equivalent to 105 mL/min of oxygen, using a Penn-Plax Airtech 2K0 aquarium air pump. Samples were taken at specific time intervals: 17, 33, 50, and 83 minutes. Control tests were also performed, including photolysis (without photocatalytic material) and adsorption under dark conditions.

For in situ monitoring, the Raman Spectroscopy technique was used using the Eddu Raman TO-ERS-532 system, manufactured by Thunder Optics and belonging to the Nanotechnology and Spectroscopy Laboratory of the UCV. This equipment is equipped with an AvaSpec-Mini spectrometer from the Avantes brand, which incorporates a 2048-pixel CMOS detector and a spectral resolution of 0.09 nm. In addition, the system includes a 532 nm laser with a line width of 0.1 nm, an optical fiber, and a compact Raman probe with a range for Raman shifts up to 175 cm⁻¹. It also has a 20X NA 40 microscope objective with a working distance of 11.8 mm, a fixed slit of 50 µm and AvaSoft 8 software for data acquisition and management. The laser operated with a power of 2.8 mW and a spectral acquisition time of 2 seconds. The data obtained were processed and visualized using SpectraGryph software version 1.2.

Figure 1.Photocatalytic reaction system with natural solar radiation. (Source: Drawing by Sandra Triana)

3. Results and discussion.

3.1. Characterization of ceramic foams.

The crystalline structure of the nanophotocatalysts (TiO₂ NPs and Cu-TiO₂ NPs) prepared in this investigation was evaluated by the XRD technique. Figure 2 depicts the XRD patterns of the undecorated and 1% Cu-decorated TiO₂ NPs samples, which show several well-defined diffraction peaks. The peaks observed at 2θ = 25.10°, 36.56°, 37.40°, 38.16°, 47.48°, 53.22°, 54.38°, 61.90° and 67.88° correspond to the anatase TiO₂ crystal plains (101), (103), (004), (112), (200), (105), (211), (204) and (116), respectively, coinciding with card number 00-900-8216.

The XRD patterns show no evidence of the presence of copper oxides, suggesting that the Cu atoms are in a uniformly dispersed state. In addition to the characteristic TiO₂ peaks, the absence of impurity peaks demonstrates that no aggregated phases are generated during the Cu-TiO₂ NPs synthesis method used in this investigation. Despite using different synthesis methods, these results are consistent with previous research by (Dorraj et al., 2017), (Lin et al., 2018), (Preda et al., 2022), and (Raheem et al., 2023).

Calculations performed from Equation 1 indicate that the crystallite sizes are 21.44 nm for TiO₂ NPs and 20.36 nm for Cu-TiO₂ NPs. The radiation decrease in particle size might be the result of the interaction between copper and TiO₂. These results are consistent with previous studies reported by (Turkten et al., 2019), (Manga et al., 2019), (Preda et al., 2022), and (Leong et al., 2022).

Figure 2.XRD patterns of TiO2 NPs samples (blue), Cu-TiO2 NPs (orange), and anatase reference (green). (Source: made by the authors)

The results are significant since TiO₂ NPs function as photocatalysts in the ceramic foams developed in this study. These NPs have been found to be in their anatase phase, which is considered the most active in radiation-accelerated catalysis processes (Aguilar et al., 2022). Likewise, the nano-scale particle size of the photocatalytic materials has a crucial impact on the optical behavior of the mixture, as well as on the distribution of radiation within the reactor and the efficiency of the photocatalytic process (Cassano & Alfano, 2000)

An analysis using the XRD technique was performed to determine the structure of the synthesized ceramic foams. The X-ray diffractogram of the EC0 ceramic foams is presented in Figure 3. The XRD results showed a broad peak centered at 2θ between 20° and 30°, without the presence of sharp peaks, showing the amorphous nature of the biogenic silica obtained from rice husk ash. No crystalline silica phases were seen in the XRD patterns, suggesting that the SiO₂ in the ash is amorphous. In addition, diffraction peaks related to the anatase crystalline phase of TiO₂ were found, as mentioned above. These results are consistent with previous studies conducted by (Fernández et al., 2019), (Porrang et al., 2021), (Hoerudin et al., 2022), (Shrestha et al., 2023), and (Pereira et al., 2023).

Figure 3.XRD pattern of the photocatalytic ceramic foam EC0. (Source: made by the authors)

The photocatalytic ceramic foam EC0 was characterized using the SEM technique, the results of which are presented in Figure 4. A rough morphology was observed, composed of a structure of agglomerates of hemispherical particles with an average size of 0.22 µm. The image reveals that the surfaces have dark pigmentation, which corresponds to porous cavities. These pores have an irregular shape and a size that varies between 0.1 µm and 0.4 µm.

Figure 4.SEM micrograph of the EC0 photocatalytic ceramic foam. (Source: made by the authors)

To better understand the interaction between the biogenic silica matrix and the TiO₂ NPs, a SEM-EDS analysis was conducted. When seeing the EDS spectrum of samples EC0 (Figure 5a) and EC1 (Figure 5b), a composition rich in Si and Ti atoms is evident. In both spectra, the high oxygen content (57% and 48%, respectively) is consistent with the presence of the SiO₂ and TiO₂ network. In addition, the presence of K atoms, oriinating from the solvent used in the synthesis, is seen, and in the case of the EC1 foam made up of SiO₂/Cu-TiO₂ NPs, the presence of copper was detected, as expected (See Table 1).

Figure 5.SEM-EDS analysis of EC0 (a) and EC1 (b). (Source: made by the authors)

Table 1.EDS analysis of photocatalytic ceramic foams.
Sample	Element	%Weight	%Atomic
EC0	O	57.78	77.13
	Si	9.89	7.65
	K	0.91	0.50
	Ti	32.42	14.71
EC1	O	48.19	68.45
	Si	20.2	16.68
	K	2.21	1.29
	Ti	27.54	13.06
	Cu	1.44	0.52

3.2. Photocatalytic activity.

During the in situ monitoring of the photocatalytic reaction, the Raman spectroscopy technique was employed, which has been widely used in drug quantification studies (Borio et al., 2012). Raman spectroscopy is a technique that allows the measurement of the vibration modes of a sample, which provides detailed information about its chemical composition. The resulting spectrum shows a distribution of peaks corresponding to the specific molecular vibrations of the analyzed sample. These peaks can be used to identify and quantify chemical substances, such as drugs, based on their frequency and intensity (Shende et al., 2014).

In pharmaceutical manufacturing and finished product testing, figuring out drug content through high-performance liquid chromatography (HPLC) testing is a time-consuming and potentially destructive process. In contrast, Raman spectroscopy has appeared as a widely used technique for the quantification of active pharmaceutical ingredients (APIs) and excipients in drugs, as well as for the identification and quantification of crystal polymorphism. This technique is rapid, convenient, noninvasive, and nondestructive, allowing for the minimization of sample preparation and providing highly specific information on the chemical composition of dense and highly turbid samples. Furthermore, being a solvent-free technique, Raman spectroscopy is positioned as an attractive and promising tool in the framework of green chemistry ((Bleye et al., 2013); (Mojica et al., 2018); (Zhao et al., 2022)).

ACP is composed of an aromatic ring, a carbonyl group (C=O), an alcohol group and nitrogen (Figure 6). In the specific case of ACP, its Raman spectrum (Figure 7a) is dominated by characteristic peaks such as the amide I (C=O) at 1625 cm^-1, the amide II (C-N stretching, N-H bending) at 1575 cm^-1, the C–H bond at 1225 cm^-1, and the phenyl ring at 800 cm^-1. The peaks at 1175 cm^-1, 1275 cm^-1, and 1325 cm^-1 were separately derived from the C-N-C symmetric stretching vibration, the benzene –OH stretching vibration, and the CH₃ symmetric variant, respectively. Two of these peaks (1225 and 1625 cm^-1) are only observed for ACP and can be used as marker peaks to identify and quantify any sample containing ACP (Mojica et al., 2018) (Zhao et al., 2022).

Figure 6.Chemical structure of ACP. (Source: (Srabovic et al., 2017))

In this research, the conventional method of measuring Raman peak intensities (area) was used to quantify ACP. The peak at 1600 was chosen to conduct the quantitative analysis of ACP, which corresponds to C=O stretching with the contribution of ring stretching (C=C) (Figure 7b). A calibration curve was performed with ACP solutions in a concentration range from 2 ppm to 14 ppm (Figure 7c), starting from the principle that the amount of active ingredient has a direct effect on the generated signal. The most reported validation criteria are the coefficient of determination (R²) of the calibration curve, which in this study was 0.9849, and the concentration range, to evaluate the relationship between concentration and Raman signal in quantitative detections. In the linear calibration range, the concentration is estimated by linear regression (Cailletaud et al., 2018).

Figure 7.Raman spectrum of ACP (a), zoom to Raman peak at 1600 cm-1 at different ACP concentrations (b) and calibration curve of ACP (c). (Source: made by the authors)

By applying this method, the ACP solutions treated photocatalytically with EC0 and EC1 were analyzed under natural solar irradiation, using Raman spectroscopy as a characterization technique. Figure 8 presents the graph illustrating the ACP degradation efficiency as a function of time. Initially, an adsorption process was identified in the foams that reached an average of 29%, which represents a key stage within the photocatalytic mechanism (Ugarteburi, 2018).

Regarding the efficiency of photocatalytic degradation, the results indicate that the use of 1.5 g/L of the EC1 allowed a 91.0% degradation of the ACP to be achieved in a period of 83 minutes. In comparison, under the same load and time conditions, the maximum efficiency obtained with EC0 was 68.3%.

Figure 8.ACP degradation efficiency in systems with EC0, EC1 and adsorption as a function of time, with a concentration of [ACP] = 10 ppm, pH = 8, [EC0] = [EC1] = 1.5 g/L and irradiance of 924 W/m2. (Source: made by the authors)

On the other hand, Figure 9 shows the Raman spectra corresponding to the amide I peak recorded during the in-situ monitoring of the photocatalytic reaction of ACP for the systems with EC0 and EC1. In these spectra, a progressive decrease in the area under the curve is observed as the reaction time progresses. Particularly, in the case of EC1, the peak associated with amide I disappears completely after 33 minutes of reaction, evidencing its greater efficiency in the degradation of the compound.

Figure 9.Photocatalytic degradation of ACP using ceramic foams with a loading of 1.5 g/L, monitored by Raman spectroscopy: EC0 (a) and EC1 (b). (Source: made by the authors)

The results obtained indicate that the combination of the SiO₂/Cu-TiO₂ NPs foam system, called EC1, presents a higher efficiency in the degradation of ACP compared to the control and EC0 experiments. This superiority in efficiency is attributed to the fact that, in the heterogeneous photocatalysis process, the catalyst is activated by high-energy photons. During these reactions, an electron from the valence band is promoted to the conduction band, generating a photohole in the semiconductor due to an external source of energy, in this case, natural solar radiation. The TiO₂ semiconductor, modified with Cu²⁺ metal ions, plays a key role in preventing charge recombination, which optimizes the photocatalytic process. In addition, copper shifts the absorption spectrum towards lower energy regions, expanding the amount of usable radiation in the UV-visible range and contributing significantly to the overall performance of the process (Aguilar et al., 2022) (Adamu et al., 2023).

4. Conclusions.

Innovative photocatalytic ceramic foams have been developed using biogenic silica extracted from rice husks and TiO₂ NPs, both in their pure form and decorated with copper (EC0 and EC1, respectively). XRD characterization confirmed that TiO₂ is in its anatase phase, while analysis of the photocatalytic ceramic foams revealed the amorphous nature of the biogenic silica. On the other hand, the SEM-EDS study showed a rough morphology composed of a network of hemispherical particle agglomerates and confirmed the presence of copper in the EC1 ceramic foams.

The improvement in the photocatalytic activity of EC1 is attributed to a lower charge recombination rate and a longer lifetime of the photogenerated charges. This is because copper can induce doping states near the top of the valence band, which enhances the absorption in the visible spectrum through the Cu 3d-Ti 3d optical transition. In terms of performance, 91.0% degradation of ACP was achieved in a time of 83 min using a loading of 1.5 g/L of photocatalytic ceramic foam (EC1) under natural solar irradiation with an intensity of 924 W/m². This finding represents a significant advance in the photodegradation of emerging contaminants and provides valuable insights into the potential use of photocatalytic materials in the remediation of contaminated waters.

Acknowledgements

The abstract of this paper was presented at the Sustainable Water Management and Resource Adaptation: Security and Energy Nexus (SWMRA) Conference – 1st Edition, which was held on the 12^th – 13^th of November 2024.

The authors would like to express their gratitude to the National Fund for Science, Technology, and Innovation (Fonacit) for the funding provided to conduct this research, which is part of project No. 202300063. They also appreciate the valuable support provided by Dr. Paulino Betancourt, from the Center for Catalysis, Petroleum and Petrochemistry of the School of Chemistry of the Faculty of Sciences of the Central University of Venezuela.

Ethics approval

Not applicable.

Conflict of interest

The authors declare that there is no competing interest.

References

Adamu A., Isaacs M., Boodhoo K., Abegão F.R.. Investigation of Cu/TiO2 synthesis methods and conditions for CO2 photocatalytic reduction via conversion of bicarbonate/carbonate to formate. Journal of CO2 Utilization. 2023; 70(January)DOI
Aguilar C., Cruz A., Montalvo C., Ruiz A., Oros S., Figueroa S., Abatal M., Anguebes F., Córdova V.. Effect of kinetics on the photocatalytic degradation of acetaminophen and the distribution of major intermediate with anatase-Ag synthesized by sol-gel under visible irradiation. Frontiers in Environmental Science. 2022; 10(October):1-11. DOI
Borio V., Vinha R., Nicolau R., Oliveira H., Lima C., Silveira L.. Quantitative Evaluation of Acetaminophen in Oral Solutions by Dispersive Raman Spectroscopy for Quality Control. Spectroscopy: An International Journal. 2012; 27(4):215-228. DOI
Cailletaud J., Bleye C., Dumont E., Sacré P.Y., Netchacovitch L., Gut Y., Boiret M., Ginot Y.M., Hubert P., Ziemons E.. Critical review of surface-enhanced Raman spectroscopy applications in the pharmaceutical field. Journal of Pharmaceutical and Biomedical Analysis. 2018; 147:458-472. DOI
Cassano A., Alfano O.. Reaction engineering of suspended solid heterogeneous photocatalytic reactors. Catalysis Today. 2000; 58(2–3):167-197. DOI
Castillo J., Arcuri M., Vargas V., Piscitelli V.. Synthesis of nanocomposites SiO2@Co3O4, SiO2@ZnO, and SiO2@CuO from rice husks: spectroscopy and optical properties. Applied Physics A. 2022; 128(2)DOI
Bleye C., Dumont E., Rozet E., Sacré P.Y., Chavez P.F., Netchacovitch L., Piel G., Hubert P., Ziemons E.. Determination of 4-aminophenol in a pharmaceutical formulation using surface enhanced Raman scattering: From development to method validation. Talanta. 2013; 116:899-905. DOI
Dorraj M., Alizadeh M., Sairi N., Basirun W., Goh B., Woi P., Alias Y.. Enhanced visible radiation photocatalytic activity of copper-doped titanium oxide–zinc oxide heterojunction for methyl orange degradation. Applied Surface Science. 2017; 414:251-261. DOI
Espiga L.. Universidad Politecnica de Catalunya. 2018. Publisher Full Text
Fernández M., Matos J., Montaña R., Poon P., Lanfredi S., Praxedes F., Hernández J., Calvino J., Rodríguez E., Rodríguez E., Ania C.. Sunradiation photoactivity of rice husks-derived biogenic silica. Catalysis Today. 2019; 328(December):125-135. DOI
Fujishima A., Honda K.. Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature. 1972; 238:37-38.
Gonzalez K., Quesada I., Aleksandrova F., Julcour C., Andriantsiferana C., Manero M., Albasi C., Jáuregui U.. DEGRADATION OF PARACETAMOL IN AQUEOUS SOLUTION: COMPARISON OF DIFFERENT UV INDUCED ADVANCED OXIDATION PROCESSES. Latin American Applied Research - An International Journal. 2016; 46(3):115-120. DOI
Gupta S., Gandhi J., Kokate S., Raikar L., Gupta V., Prakash H.. Augmented photocatalytic degradation of Acetaminophen using hydrothermally treated g-C3N4 and persulfate under LED irradiation. Heliyon. 2023; 9(5)DOI
Hoerudin Setyawan, N. Suismono, Purwaningsih H., Apriliani N.. Morphology, Extraction Yield, and Properties of Biogenic Silica Nanoparticles from Indonesian Rice Husk as Influenced by Solvent Type and Aging Time. IOP Conference Series: Earth and Environmental Science. 2022; 1024(1)DOI
Kaur R., Kaur A., Kaur R., Singh S., Bhatti M., Umar A., Baskoutas S., Kansal S.. Cu-BTC metal organic framework (MOF) derived Cu-doped TiO2 nanoparticles and their use as visible radiation active photocatalyst for the decomposition of ofloxacin (OFX) antibiotic and antibacterial activity. Advanced Powder Technology. 2021; 32(5):1350-1361. DOI
Leong C.Y., Teh H.L., Chen M.C., Lee S.L.. Effect of Synthesis Methods on Properties of Copper Oxide Doped Titanium Dioxide Photocatalyst in Dye Photodegradation of Rhodamine B. Science and Technology Indonesia. 2022; 7(1):91-97. DOI
Lin J.C., Sopajaree K., Jitjanesuwan T., Lu M.. Application of visible radiation on copper-doped titanium dioxide catalyzing degradation of chlorophenols. Separation and Purification Technology. 2018; 191(June 2017):233-243. DOI
Manga I., Rao S., Lakshmi D., Chandra R., Padmaja S., Divya G.. Poly 3-Thenoic acid sensitized, Copper doped anatase/brookite TiO2 nanohybrids for enhanced photocatalytic degradation of an organophosphorus pesticide. Journal of Environmental Chemical Engineering. 2019; 7(4)DOI
Mojica E., Zapata J., Vedad J., Desamero R., Dai Z.. Analysis of over-the-counter drugs using Raman spectroscopy. ACS Symposium Series. 2018; 1305:69-91. DOI
Moongraksathum B., Shang J.-Y., Chen Y.-W.. Photocatalytic Antibacterial Effectiveness of Cu-Doped TiO2 Thin Film Prepared via the Peroxo Sol-Gel Method. Catalysts. 2018; 8(9)DOI
Nevárez M., Espinoza P., Quiroz F., Ohtani B.. Fotocatálisis: inicio, actualidad y perspectivas a través del TiO2. Avances En Química. 2017; 12:45-59.
Ochuma I., Osibo O., Fishwick R., Pollington S., Wagland A., Wood J., Winterbottom M.. Three-phase photocatalysis using suspended titania and titania supported on a reticulated foam monolith for water purification. Catalysis Today. 2007; 128(1-2 SPEC. ISS.):100-107. DOI
Pereira J., Castillo J., Labrador H.. Evaluación de las propiedades tribológicas y la viscosidad de un lubricante basado en un nanofluido de sílice ( SiO2 ) Evaluation of the tribological properties and the viscosity of a lubricant based on a silica nanofluid ( SiO2. Revista Ciencia e Ingenería. 2023; 44(December 2022):79-88.
Porrang S., Rahemi N., Davaran S., Mahdavi M., Hassanzadeh B.. Preparation and in-vitro evaluation of mesoporous biogenic silica nanoparticles obtained from rice and wheat husk as a biocompatible carrier for anti-cancer drug delivery. European Journal of Pharmaceutical Sciences. 2021; 163(April)DOI
Preda S., Pandele-Cușu J., Petrescu S., Ciobanu E., Petcu G., Culiță D., Apostol N., Costescu R., Raut I., Constantin M., Predoană L.. Photocatalytic and Antibacterial Properties of Doped TiO2 Nanopowders Synthesized by Sol−Gel Method. Gels. 2022; 8(10)DOI
Raheem S., Sattar J., Al-Jubori S.. Characterization of Titanium dioxide (TiO2 ) Nanoparticles Biosynthesized using Leuconostoc spp. Isolated from Cow’s Raw Milk. Proceedings of the Pakistan Academy of Sciences: B. Life and Environmental Sciences. 2023; 60(1):133-142. DOI
Rodríguez M., Barrera C.. Publicaciones UAEM. 2020. Publisher Full Text
Shende C., Smith W., Brouillette C., Farquharson S.. Drug Stability Analysis by Raman Spectroscopy. Pharmaceutics. 2014; 6(4):651-662. DOI
Shrestha D., Nayaju T., Kandel M.R., Pradhananga R., Park C., Kim C.. Rice husk-derived mesoporous biogenic silica nanoparticles for gravity chromatography. Heliyon. 2023; 9(4)DOI
Srabovic M., Huremovic M., Catovic B., Muratovic S.. Design synthesis and crystallization of acetaminophen. Journal of Chemical , Biological and Physical Sciences. 2017; 7(January):218-230.
Turkten N., Cinar Z., Tomruk A., Bekbolet M.. Copper-doped TiO2 photocatalysts: application to drinking water by humic matter degradation. Environmental Science and Pollution Research. 2019; 26(36):36096-36106. DOI
Ugarteburi A.. Optimizacion de la reologia de componentes Fotocataliticos para aplicaciones avanzadas en elementos de fachada [Universidad Politécnica de Catalunya. 2018. Publisher Full Text
Warren Z., Guaraldo T., Martins A., Wenk J., Mattia D.. Photocatalytic foams for water treatment: A systematic review and meta-analysis. Journal of Environmental Chemical Engineering. 2023; 11(1)DOI
Yang L., Yu L., Ray M.. Degradation of paracetamol in aqueous solutions by TiO2 photocatalysis. Water Research. 2008; 42(13):3480-3488. DOI
Zhao X., Wang N., Zhu M., Qiu X., Sun S., Liu Y., Zhao T., Yao J., Shan G.. Application of Transmission Raman Spectroscopy in Combination with Partial Least-Squares (PLS) for the Fast Quantification of Paracetamol. Molecules. 2022; 27(5)DOI

Plum Analytics

Read Counter : 628 Download : 370

Share Now

[BIBR-1] Adamu A., Isaacs M., Boodhoo K., Abegão F.R.. Investigation of Cu/TiO2 synthesis methods and conditions for CO2 photocatalytic reduction via conversion of bicarbonate/carbonate to formate. Journal of CO2 Utilization. 2023; 70(January)DOI

[BIBR-2] Aguilar C., Cruz A., Montalvo C., Ruiz A., Oros S., Figueroa S., Abatal M., Anguebes F., Córdova V.. Effect of kinetics on the photocatalytic degradation of acetaminophen and the distribution of major intermediate with anatase-Ag synthesized by sol-gel under visible irradiation. Frontiers in Environmental Science. 2022; 10(October):1-11. DOI

[BIBR-3] Borio V., Vinha R., Nicolau R., Oliveira H., Lima C., Silveira L.. Quantitative Evaluation of Acetaminophen in Oral Solutions by Dispersive Raman Spectroscopy for Quality Control. Spectroscopy: An International Journal. 2012; 27(4):215-228. DOI

[BIBR-4] Cailletaud J., Bleye C., Dumont E., Sacré P.Y., Netchacovitch L., Gut Y., Boiret M., Ginot Y.M., Hubert P., Ziemons E.. Critical review of surface-enhanced Raman spectroscopy applications in the pharmaceutical field. Journal of Pharmaceutical and Biomedical Analysis. 2018; 147:458-472. DOI

[BIBR-5] Cassano A., Alfano O.. Reaction engineering of suspended solid heterogeneous photocatalytic reactors. Catalysis Today. 2000; 58(2–3):167-197. DOI

[BIBR-6] Castillo J., Arcuri M., Vargas V., Piscitelli V.. Synthesis of nanocomposites SiO2@Co3O4, SiO2@ZnO, and SiO2@CuO from rice husks: spectroscopy and optical properties. Applied Physics A. 2022; 128(2)DOI

[BIBR-7] Bleye C., Dumont E., Rozet E., Sacré P.Y., Chavez P.F., Netchacovitch L., Piel G., Hubert P., Ziemons E.. Determination of 4-aminophenol in a pharmaceutical formulation using surface enhanced Raman scattering: From development to method validation. Talanta. 2013; 116:899-905. DOI

[BIBR-8] Dorraj M., Alizadeh M., Sairi N., Basirun W., Goh B., Woi P., Alias Y.. Enhanced visible radiation photocatalytic activity of copper-doped titanium oxide–zinc oxide heterojunction for methyl orange degradation. Applied Surface Science. 2017; 414:251-261. DOI

[BIBR-9] Espiga L.. Universidad Politecnica de Catalunya. 2018. Publisher Full Text

[BIBR-10] Fernández M., Matos J., Montaña R., Poon P., Lanfredi S., Praxedes F., Hernández J., Calvino J., Rodríguez E., Rodríguez E., Ania C.. Sunradiation photoactivity of rice husks-derived biogenic silica. Catalysis Today. 2019; 328(December):125-135. DOI

[BIBR-11] Fujishima A., Honda K.. Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature. 1972; 238:37-38.

[BIBR-12] Gonzalez K., Quesada I., Aleksandrova F., Julcour C., Andriantsiferana C., Manero M., Albasi C., Jáuregui U.. DEGRADATION OF PARACETAMOL IN AQUEOUS SOLUTION: COMPARISON OF DIFFERENT UV INDUCED ADVANCED OXIDATION PROCESSES. Latin American Applied Research - An International Journal. 2016; 46(3):115-120. DOI

[BIBR-13] Gupta S., Gandhi J., Kokate S., Raikar L., Gupta V., Prakash H.. Augmented photocatalytic degradation of Acetaminophen using hydrothermally treated g-C3N4 and persulfate under LED irradiation. Heliyon. 2023; 9(5)DOI

[BIBR-14] Hoerudin Setyawan, N. Suismono, Purwaningsih H., Apriliani N.. Morphology, Extraction Yield, and Properties of Biogenic Silica Nanoparticles from Indonesian Rice Husk as Influenced by Solvent Type and Aging Time. IOP Conference Series: Earth and Environmental Science. 2022; 1024(1)DOI

[BIBR-15] Kaur R., Kaur A., Kaur R., Singh S., Bhatti M., Umar A., Baskoutas S., Kansal S.. Cu-BTC metal organic framework (MOF) derived Cu-doped TiO2 nanoparticles and their use as visible radiation active photocatalyst for the decomposition of ofloxacin (OFX) antibiotic and antibacterial activity. Advanced Powder Technology. 2021; 32(5):1350-1361. DOI

[BIBR-16] Leong C.Y., Teh H.L., Chen M.C., Lee S.L.. Effect of Synthesis Methods on Properties of Copper Oxide Doped Titanium Dioxide Photocatalyst in Dye Photodegradation of Rhodamine B. Science and Technology Indonesia. 2022; 7(1):91-97. DOI

[BIBR-17] Lin J.C., Sopajaree K., Jitjanesuwan T., Lu M.. Application of visible radiation on copper-doped titanium dioxide catalyzing degradation of chlorophenols. Separation and Purification Technology. 2018; 191(June 2017):233-243. DOI

[BIBR-18] Manga I., Rao S., Lakshmi D., Chandra R., Padmaja S., Divya G.. Poly 3-Thenoic acid sensitized, Copper doped anatase/brookite TiO2 nanohybrids for enhanced photocatalytic degradation of an organophosphorus pesticide. Journal of Environmental Chemical Engineering. 2019; 7(4)DOI

[BIBR-19] Mojica E., Zapata J., Vedad J., Desamero R., Dai Z.. Analysis of over-the-counter drugs using Raman spectroscopy. ACS Symposium Series. 2018; 1305:69-91. DOI

[BIBR-20] Moongraksathum B., Shang J.-Y., Chen Y.-W.. Photocatalytic Antibacterial Effectiveness of Cu-Doped TiO2 Thin Film Prepared via the Peroxo Sol-Gel Method. Catalysts. 2018; 8(9)DOI

[BIBR-21] Nevárez M., Espinoza P., Quiroz F., Ohtani B.. Fotocatálisis: inicio, actualidad y perspectivas a través del TiO2. Avances En Química. 2017; 12:45-59.

[BIBR-22] Ochuma I., Osibo O., Fishwick R., Pollington S., Wagland A., Wood J., Winterbottom M.. Three-phase photocatalysis using suspended titania and titania supported on a reticulated foam monolith for water purification. Catalysis Today. 2007; 128(1-2 SPEC. ISS.):100-107. DOI

[BIBR-23] Pereira J., Castillo J., Labrador H.. Evaluación de las propiedades tribológicas y la viscosidad de un lubricante basado en un nanofluido de sílice ( SiO2 ) Evaluation of the tribological properties and the viscosity of a lubricant based on a silica nanofluid ( SiO2. Revista Ciencia e Ingenería. 2023; 44(December 2022):79-88.

[BIBR-24] Porrang S., Rahemi N., Davaran S., Mahdavi M., Hassanzadeh B.. Preparation and in-vitro evaluation of mesoporous biogenic silica nanoparticles obtained from rice and wheat husk as a biocompatible carrier for anti-cancer drug delivery. European Journal of Pharmaceutical Sciences. 2021; 163(April)DOI

[BIBR-25] Preda S., Pandele-Cușu J., Petrescu S., Ciobanu E., Petcu G., Culiță D., Apostol N., Costescu R., Raut I., Constantin M., Predoană L.. Photocatalytic and Antibacterial Properties of Doped TiO2 Nanopowders Synthesized by Sol−Gel Method. Gels. 2022; 8(10)DOI

[BIBR-26] Raheem S., Sattar J., Al-Jubori S.. Characterization of Titanium dioxide (TiO2 ) Nanoparticles Biosynthesized using Leuconostoc spp. Isolated from Cow’s Raw Milk. Proceedings of the Pakistan Academy of Sciences: B. Life and Environmental Sciences. 2023; 60(1):133-142. DOI

[BIBR-27] Rodríguez M., Barrera C.. Publicaciones UAEM. 2020. Publisher Full Text

[BIBR-28] Shende C., Smith W., Brouillette C., Farquharson S.. Drug Stability Analysis by Raman Spectroscopy. Pharmaceutics. 2014; 6(4):651-662. DOI

[BIBR-29] Shrestha D., Nayaju T., Kandel M.R., Pradhananga R., Park C., Kim C.. Rice husk-derived mesoporous biogenic silica nanoparticles for gravity chromatography. Heliyon. 2023; 9(4)DOI

[BIBR-30] Srabovic M., Huremovic M., Catovic B., Muratovic S.. Design synthesis and crystallization of acetaminophen. Journal of Chemical , Biological and Physical Sciences. 2017; 7(January):218-230.

[BIBR-31] Turkten N., Cinar Z., Tomruk A., Bekbolet M.. Copper-doped TiO2 photocatalysts: application to drinking water by humic matter degradation. Environmental Science and Pollution Research. 2019; 26(36):36096-36106. DOI

[BIBR-32] Ugarteburi A.. Optimizacion de la reologia de componentes Fotocataliticos para aplicaciones avanzadas en elementos de fachada [Universidad Politécnica de Catalunya. 2018. Publisher Full Text

[BIBR-33] Warren Z., Guaraldo T., Martins A., Wenk J., Mattia D.. Photocatalytic foams for water treatment: A systematic review and meta-analysis. Journal of Environmental Chemical Engineering. 2023; 11(1)DOI

[BIBR-34] Yang L., Yu L., Ray M.. Degradation of paracetamol in aqueous solutions by TiO2 photocatalysis. Water Research. 2008; 42(13):3480-3488. DOI

[BIBR-35] Zhao X., Wang N., Zhu M., Qiu X., Sun S., Liu Y., Zhao T., Yao J., Shan G.. Application of Transmission Raman Spectroscopy in Combination with Partial Least-Squares (PLS) for the Fast Quantification of Paracetamol. Molecules. 2022; 27(5)DOI

Performance of Biogenic Silica Photocatalytic Ceramic Foams and Cu-TiO2 NPs in the Degradation of Emerging Pollutants under Natural Solar Radiation

Abstract

Full text article

References

Authors

Address

Social Media

Article Sidebar

Abstract

Full text article

References

Authors

Article Details