Insight into the Photocatalytical Activity of TiO2 Nanoparticles Through the Electrochemical Characterization of Carbon Paste Electrodes

Author(s)

Soares, Gabriela Byzynski ^{[1, 2]} ; Vaz, Carlos M. P. ^[2] ; Ribeiro, Caue ^[2] ; Hermans, Ive ^{[3, 4, 5]}

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

^[2] Embrapa Instrumentat, BR-13560970 Sao Carlos, SP - Brazil

^[3] ETH, Dept Chem & Appl Biosci, CH-8093 Zurich - Switzerland

^[4] Univ Wisconsin, Dept Chem, Madison, WI 53706 - USA

^[5] Univ Wisconsin, Dept Chem & Biol Engn, Madison, WI 53706 - USA

• Document type: Journal article
• Source: ELECTROCATALYSIS; v. 6, n. 1, p. 92-101, JAN 2015.
• Web of Science Citations: 5

Abstract

We propose a methodology to study the behavior of semiconductor nanoparticles-especially TiO2 nanoparticles-in photoactivated processes via electrochemical studies, using solid electrodes instead of thin-film electrodes. This strategy allows the comparison of properties probed from freestanding nanoparticles with the results of electrochemical characterization, without grain growth or texturization effects, frequently observed in thin-film electrodes. In this study, solid electrodes prepared with homogenized carbon paste and TiO2 were characterized. The TiO2/carbon paste electrode showed lower currents than the carbon paste electrode under UVC illumination. The electrode containing 15 % TiO2/carbon paste showed better results for electroanalytical characterization. However, for electrolysis, the carbon paste electrode with 60 % TiO2 was used, as 15 to 45 % (w/w) TiO2 content was deemed insufficient for this purpose. In order to compare the electrochemical characterization with photocatalytical properties, the degradation of rhodamine B (Rhod-B) dye was used. The reaction order for the Rhod-B degradation was between first and second order, which suggests that the products of the reaction may interfere with the decomposition itself. The results will enhance the establishment of a valuable characterization route to support future research regarding the influence of different materials in photodegradation processes. (AU)

• FAPESP's process: 09/10998-3 - Kinetic parameters involved in the photodegradation of pesticides catalyzed by TiO2 nanoparticles: comparative studies on the contribution of charge transfer and free radicals oxidation
• Grantee: Gabriela Byzynski Soares
• Support Opportunities: Scholarships in Brazil - Doctorate