Orientation Engineering of Nanoporous BiVO4 Photoanodes Toward Boosted Glycerol Valorization and Hydrogen Generation

Abstract

Photoelectrocatalysis has the capability to utilize solar energy to produce hydrogen and valuable chemicals; however, their conversion efficiency remains to reach practical thresholds. Here, a rapid-ramping annealing strategy is reported to synthesize nanoporous Mo-doped bismuth vanadate (MBVO) photoanodes with (001)-preferred orientation. This approach leverages the enhanced carrier transport along the crystallographic [001] direction, optimizing the bulk photoelectrical properties of the MBVO photoanodes. By substituting the surface oxygen evolution reaction with the glycerol oxidation reaction, the photoconversion efficiency is significantly boosted, reaching a photocurrent density of 7.45 mA cm⁻² at 1.23 V versus RHE and an incident photon-to-current conversion efficiency of ≈100% for hydrogen generation, accompanied by the production of value-added products in a high rate (≈1700 mmol m⁻² h⁻¹ in total) with a total Faradaic efficiency up to 96%. These results shed light on the construction of practical photoelectrocatalysis systems by demonstrating the potential of bulk-phase engineering coupled with surface reaction design.