Functionalized ZIF-67@CdS for photocatalytic oxidation of benzyl alcohol coupled with hydrogen production

Abstract

ZIF-67 has garnered much attention in the field of photocatalytic water splitting due to the advantages of MOFs and zeolite sieves. However, post-modification and composite strategies have emerged as effective approaches to enhance its photocatalytic performance, particularly in enabling bi-functionality for oxidation-coupled reduction reactions. In this study, 2-mercaptobenzimidazole (MBI) modified ZIF-67 and cadmium sulfide (CdS) composites were prepared to investigate their application in photocatalytic oxidation-coupled hydrogen evolution reactions. The results demonstrated an enhancement in hydrogen production performance over CdS@ZIF-67-MBI, with an increase from 2.39 mmol g⁻¹ h⁻¹ to 4.49 mmol g⁻¹ h⁻¹ upon the introduction of MBI. Moreover, the conversion efficiency of benzyl alcohol reached an improved value of 58.5%. The study findings revealed that the heterogeneous coupling between ZIF-67 and CdS, along with the effective charge transfer facilitated by the anion S, played a decisive role in promoting charge–hole separation of composite materials and improving carrier transport efficiency. This demonstrates the viability of utilizing ZIF-67 in a bifunctional photocatalytic reaction system, thereby paving the way for broader applications of ZIF-67.