Photoassisted chemical energy conversion into electricity using a sulfite-iron photocatalytic fuel cell

Author(s)

Sena, Izabela Campos ; Sales, Davi de Oliveira ; Andrade, Tatiana Santos ; Rodriguez, Mariandry ; da Silva, Adilson Candido ; Esteves Nogueira, Francisco Guilherme ; Rodrigues, Jairo Lisboa ; de Mesquita, Joao Paulo ; Pereira, Marcio Cesar

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 881, p. 10-pg., 2021-01-15.

Abstract

Photocatalytic fuel cells (PFC) are light-assisted devices that convert chemical energy into electricity. However, conventional PFC produces extremely low photocurrents due to the slow kinetics of the photoanodes to oxidized organic fuels, thus limiting the power generation. Here, an all-inorganic PFC manufactured with heterostructured W-BiVO4/V2O5 photoanode separated from a platinum cathode by a porous membrane is described. Sulfite ions are used as a fuel anolyte and Fe3+ is the catholyte. Under lighting, the W-BiVO4/V2O5 photoanode is exceptionally efficient for oxidizing sulfite to sulfate, which results in a high photocurrent output. Under optimized conditions, the W-BiVO4/V2O5-Pt cell produces a high short-circuit current of 8.79 mA cm(-2), an open-circuit potential 0.85 V, and a power density of 1.89 mW cm(-2) at 4.30 mA cm(-2). The excellent PFC performance is attributed to the photovoltage generated by W-BiVO4/sulfite-sulfate liquid-junctions and efficient charge separation and hole transport in the photoanode bulk promoted by theW-BiVO4/V2O5 junctions. Also, the kinetics of redox reactions are fast, eliminating the use of cocatalysts. Thus, this simple PFC concept can be a viable alternative for electricity generation. (AU)

• FAPESP's process: 18/09723-9 - CO2 PHOTOCONVERSION IN PRODUCTS WITH VALUE-ADDED: EXPERIMENTAL AND THEORIC STUDIES
• Grantee: Francisco Guilherme Esteves Nogueira
• Support Opportunities: Regular Research Grants