Achieving high selectivity in photoelectrochemical oxidation of glycerol on WO3 nanosheets coupled with TiO2 nanorods arrays

Abstract

Developing highly efficient photocatalysts for the selective conversion of glycerol into valuable chemicals is of paramount importance. However, achieving the selective oxidation of glycerol to valuable C3 chemicals poses significant challenges. In this study, we employed a two-step hydrothermal method to synthesize a photoelectrochemical (PEC) photocatalyst composed of WO3 nanosheets assembled on TiO2 nanorod arrays. The synergistic interaction between WO3 and TiO2 led to outstanding performance in the selective conversion of glycerol (GLY) into glyceraldehyde (GLD) and 1,3-dihydroxyacetone (DHA). The photocatalyst achieved a selectivity of 61% for GLD and 92% for GLD + DHA, with formation rates of 319 and 160 mmol m-2h−1, respectively. Despite the excellent charge transfer properties of TiO2 nanorods, they displayed suboptimal glycerol conversion rates and tended to oxidize glycerol into lower-value products. The introduction of WO3 nanosheets in the Z-scheme heterojunction improved charge separation, enhanced glycerol adsorption and facilitated the desorption of GLD and DHA, thus improving the selectivity of GLD + DHA. This study unveils a promising approach to efficiently oxidize glycerol and demonstrates the crucial role of catalyst design in achieving selective and high-yield chemical transformations.