Solar-Driven Photoreactor for Water Remediation Based on n-Type TiO2 and p-Type Ag/AgBiW2O8/Bi2WO6 Light-Responsive Air-Fed Gas Diffusion Electrodes

Author(s)

de Medeiros, Jessyca Ferreira ; Galante, Miguel Tayar ; Bertazzoli, Rodnei ; dos Santos, Caio Guilherme Pereira ; Longo, Claudia

• Document type: Journal article
• Source: ACS ES&T WATER; v. 2, n. 6, p. 12-pg., 2022-06-10.

Abstract

Photocathodes with multiphasic Ag/AgBiW2O8/Bi2WO6 (Ag/ABW/BW) particles, obtained by hydrothermal synthesis, were evaluated for light-assisted oxygen reduction reaction (ORR). Under irradiation, electrodes of Ag/ABW/BW deposited on FTO exhibited ORR cathodic photocurrent enhancement and impedance decreasing (p-type semiconducting behavior). The Ag/ABW/BW particles were deposited on graphite sintered with PTFE; under irradiation and flow of compressed air, this gas diffusion electrode (GDE) produced H2O2 from ORR. The air-fed GDE vertical bar Ag/ABW/BW photocathode was associated with an FTO vertical bar TiO2 photoanode and externally connected with a silicon solar cell. Irradiated by a solar simulator, this photoreactor was used for remediation of amoxicillin (AMX) aqueous solution. After 3 h, 53% of AMX was degraded, while with a bare GDE, the AMX removal was 30%. Smaller values (<15%) were obtained using Pt or a GDE vertical bar Ag/ABW/BW under N-2 flow as the cathode, since these configurations preclude the H2O2 production from ORR. Thus, association of photoactive electrodes in this innovative solar-driven photoreactor provides a sustainable system for water remediation. (AU)

• FAPESP's process: 19/11353-8 - Brazilian Water Research Center (BWRC)
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 19/09838-3 - Multiuser equipments: integrated system for photo electrochemical experiments
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Multi-user Equipment Program