Photoelectrochemistry-driven selective hydroxyl oxidation of polyols: Synergy between Au nanoparticles and C₃N₄ nanosheets

Selective and efficient oxidation of a certain hydroxyl group in biomass-derived polyols is quite appealing but challenging. We herein propose a new photoelectrochemical strategy for enhancing the selectivity and kinetics of the middle hydroxyl oxidation in glycerol molecules using Au/C₃N₄ catalyst. The introduction of illumination and usage of C₃N₄ are first demonstrated to have a direct bearing on enhancing the selectivity of middle hydroxyl oxidation on Au through the electron transfer and accelerating the kinetics by accumulating photogenerated holes with moderate oxidizability. By this strategy, the selectivity of glycerol to dihydroxyacetone and turnover frequency are achieved as high as 53.7% and unprecedented 4,619 h⁻¹. The synergy of electronic interaction, localized surface plasmon resonance effect, and photogenerated carriers dual injection is revealed to account for such high selectivity and kinetics of the middle hydroxyl oxidation during the photoelectrochemical process. Our results sheds light on the photoelectrocatalysis-driven selective hydroxyl oxidation in polyols.