Generation of Schottky heterojunction (SnO2-Au NPs) transparent thin film for ciprofloxacin photodegradation

resumo

In this study, transparent Schottky heterojunction thin films composed of SnO2 and Au nanoparticles (Au NPs) were developed and applied for the photocatalytic degradation of ciprofloxacin (CIP) under UV light. The SnO2Au NPs films achieved a 75 % degradation of CIP and 70 % total organic carbon (TOC) mineralization within 180 min using only 0.02 g/L of catalyst, highlighting their exceptional efficiency compared to conventional powderbased systems. The incorporation of Au NPs significantly enhanced charge separation and reduced electron-hole recombination, as confirmed by structural and optical analyses. Optimal photocatalytic activity was observed at pH 7, following pseudo-first-order kinetics. Scavenger tests and fluorescence probing confirmed that hydroxyl radicals (center dot OH) and superoxide radicals (O2 center dot- ) were the primary active species. QTOF-MS identified five degradation intermediates, suggesting mechanisms involving defluorination, hydroxylation, and ring cleavage. In silico toxicity assessments showed reduced toxicity for most transformation products. The catalyst exhibited high stability and reusability over four cycles without detectable leaching, indicating strong potential for sustainable water treatment applications.

palavras-chave

PHOTOCATALYTIC DEGRADATION; OXIDATION; SURFACE; NANOPARTICLES; ADSORPTION; CATALYST; PATHWAYS; PRODUCTS; KINETICS; BARRIER

categoria

Chemistry; Materials Science; Physics

autores

Cuadra, JG; Molina-Prados, S; Mínguez-Vega, G; Abderrahim, LA; Colombari, J; Carda, JB; Gonçalves, NPF; Novais, RM; Labrincha, JA

Grupos

G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

3D Printed Fouling-Resistant Photoactive Membranes for Wastewater Treatment (PURAQUA)

agradecimentos

Jaime Gonzalez Cuadra gratefully acknowledges the support received through the postdoctoral contract (reference CIAPOS/2023/425) and the predoctoral contract (ref- erence CIACIF/2022/277) , both cofunded by the Valencian Community Government and the European Social Fund. This work has been funded by Ministerio de Ciencia e Innovacion with grant PRE2020-094889 funded by MCIN/AEI/10.13039/501100011033 and "ESF Investing in your future" and the project PID2022-142907OB-I00, financed by MCIN/AEI/10.13039/501100011033 and "ERDF A way of making Europe". Funding from the Generalitat Valenciana CIPROM/2023/44 is also acknowledged. The authors are very grateful to the "Serveis Centrals d'Instrumentacion Cientifica" (SCIC) of the University Jaume I for the use of the laser facilities. This work was developed within the scope of the CICECO-Aveiro Institute of Materials project, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) and LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through FCT/MCTES (PIDDAC) . Nuno Goncalves acknowledges funding from the European Union's Horizon Europe research and innovation programme under the Marie Skl-odowska- Curie Actions PF grant agreement No. 101065059 and FCT 2022.06593.CEECIND/CP1720/CT0024 (DOI10.54499/2022.06593.CEECIND/CP1720/CT0024) .