The synthesis of CdS hierarchical micro-nanostructures with different pore structure and their influence on the photocatalytic ethanol transformation

Photocatalytic ethanol conversion into high-valuable chemicals while realizing hydrogen production is attractive and challenging. In this study, flower-like, porous flower-like, and net-like CdS nanostructures were prepared by solvothermal technique and were used to investigate the effect of morphology on ethanol conversion. It was found by characterization that the one-dimensional net-like CdS had the best crystallinity and the largest specific surface area, which provided more active sites and possessed superior ethanol conversion activity. The ethanol conversion was 4.7% in 10 h with a hydrogen production rate of 1.32 mmol g⁻¹ h⁻¹ and an acetaldehyde (AA) production rate of 1.96 mmol g⁻¹ h⁻¹ with a selectivity of 51%. In comparison, 2,3-butanediol(2,3-BDO) was produced at a rate of 0.61 mmol g⁻¹ h⁻¹ with a selectivity of 32%. The pore structure of one-dimensional net-like CdS with predominantly large mesopores showed better selectivity for 2,3-BDO, indicating that the pore size of the catalyst plays an important role in the C–C coupling reaction. Further, the catalysts were modified by depositing Pt nanoparticles on net-like CdS and the photocatalytic ethanol conversion performance was improved by about 3.5 times.