BiVO 4 -Based Heterojunction Photocathode for High-Performance Photoelectrochemical Hydrogen Peroxide Production.

Photoelectrochemical (PEC) cells provide a promising solution for the synthesis of hydrogen peroxide (H 2 O 2 ). Herein, an integrated photocathode of p-type BiVO 4 (p-BVO) array with tetragonal zircon structure coupled with different metal oxide (MO x , M = Sn, Ti, Ni, and Zn) heterostructure and NiNC cocatalyst (p-BVO/MO x /NiNC) was synthesized for the PEC oxygen reduction reaction (ORR) in production of H 2 O 2 . The p-BVO/SnO 2 /NiNC array achieves the production rate 65.46 μmol L -1 h -1 of H 2 O 2 with a Faraday efficiency (FE) of 76.12%. Combined with the H 2 O 2 generation of water oxidation from the n-type Mo-doped BiVO 4 (n-Mo:BVO) photoanode, the unbiased photoelectrochemical cell composed of a p-BVO/SnO 2 /NiNC photocathode and n-Mo:BVO photoanode achieves a total FE of 97.67% for H 2 O 2 generation. The large area BiVO 4 -based tandem cell of 3 × 3 cm 2 can reach a total H 2 O 2 production yield of 338.84 μmol L -1 . This work paves the way for the rational design and fabrication of artificial photosynthetic cells for the production of liquid solar fuel.