Nanoporous MoO_(3−x)/BiVO_(4)photoanodes promoting charge separation for efficient photoelectrochemical water splitting

摘要

Owing to the relatively short hole diffusion length,severe charge recombination in the bulk of bismuth vanadate(BiVO_(4))is the key issue for photoelectrochemical water splitting.Herein,we design a nanoporous MoO_(3−x)/BiVO_(4)heterojunction photoanode to promote charge separation.The efficient electron transport properties of oxygen deficient MoO_(3−x)and the nanoporous structure are beneficial for charge separation,leading to a significantly enhanced PEC performance.The optimized MoO_(3−x)/BiVO_(4)heterojunction photoanode exhibits a photocurrent density of 5.07 mA·cm^(−2)for Na_(2)SO_(3)oxidation.By depositing FeOOH/NiOOH dual oxygen evolution cocatalysts to promote surface kinetics,a high photocurrent density of 4.81 mA·cm^(−2)can be achieved for PEC water splitting,exhibiting an excellent applied bias photon-to-current efficiency of 1.57%.Moreover,stable overall water splitting is achieved under consecutive light illumination for 10 h.We provide a proof of concept for the design of efficient BiVO_(4)-based heterojunction photoanodes for stable PEC water splitting.