Enhanced photoelectrochemical glycerol oxidation and hydrogen production using Fe-doped ZnS/ZnO nanowire heterostructures

Abstract

Achieving efficient photoelectrochemical (PEC) glycerol oxidation requires understanding and optimizing interactions between glycerol and the photoelectrode surface. In this study, we present Fe-doped ZnS/ZnO photoelectrodes, focusing on their surface properties. Incorporating Fe into ZnS improves photocatalytic performance, promoting glycerol oxidation and hydrogen production to nearly twice that of ZnO. At 1.0 V versus the reversible hydrogen electrode (VRHE), the Fe-doped ZnS/ZnO nanowires achieve a photocurrent density of 1.88 mA cm−2 and a total liquid product yield of 177.7 mmol m−2 h−1. Glyceric acid is identified as the major oxidation product, with sulfur-based structures favoring C3 product formation. Computational results also reveal that Fe-doping on the surface of ZnS can facilitate the adsorption of hydroxyl groups of glycerol, leading to efficient photocatalytic reactions on ZnS. This study clarifies the role of metal dopants in enhancing PEC glycerol oxidation and provides valuable insights for designing reactant-tailored photoelectrodes. © 2025