The modification of a BiVO 4 /WO 3 photoelectrode with Al 2 O 3 by a chemical vapor deposition (CVD) method significantly improved the faradaic efficiency for H 2 O 2 production (FE(H 2 O 2 )) in the photoelectrochemical oxidation of H 2 O. The faradaic efficiency after passing 0.9 C (after photoirradiation for 15 min using simulated solar light) was 80% using a 2.0 M KHCO 3 aqueous solution as an electrolyte. The initial FE(H 2 O 2 ) (<0.02 C) was almost 100% on the Al 2 O 3 /BiVO 4 /WO 3 photoelectrode. The thin Al 2 O 3 layer prevents the oxidative decomposition of the produced H 2 O 2 into O 2 . The applied bias photon to current efficiency (ABPE) was 2.57% based on H 2 O 2 and O 2 production on the photoanode and H 2 production on a Pt cathode. Solar light driven simultaneous H 2 O 2 production at the anode for H 2 O oxidation and the cathode for O 2 reduction was also achieved by combining a noble-metal-free biomass-derived carbon cathode without applying any external bias.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology