Remarkably enhanced acidic photoelectrochemical glycerol oxidation achieving the theoretical maximum photocurrent of BiVO4 through anion modulation

Converting biomass waste into valuable chemicals, while concurrently producing H2 via photoelectrochemical (PEC) water splitting, offers a compelling solution to energy and environmental issues, with a substantial challenge to boost the output of these high-value chemicals and H2. Herein, we report an anion modulation strategy to significantly increase the photocurrent of BiVO4 photoanodes, enabling the efficient oxidation of glycerol, alongside the hydrogen production. We find that NO3−, with its lesser affinity for BiVO4 compared to SO42−, allows for the exposure of more active bismuth sites for the oxidation of glycerol, while accelerating the reaction kinetics. The BiVO4 photoanode, in the HNO3 electrolyte, attains an unprecedented photocurrent density of 7.52 mA cm−2 at 1.23 VRHE, surpassing existing records for PEC glycerol oxidation and maintaining stability for over 10 h. The versatility of the anion modulation approach can be extended to a wide array of alcohols, promoting the upcycling of bio-waste into valuable chemical products and fuels like H2.