Charge Transfer-Regulated Bimetallic ZnCd-ZIF-8/Graphene Oxide Hybrid Nanostructures for Solar Hydrogen Generation

Zeolite imidazolate frameworks (ZIFs) have recently attracted eminent attention in the field of photocatalytic hydrogen generation. Herein, we first report and demonstrate the π–π interactions among bimetallic ZnCd-ZIF-8 and GO and their probed catalytic activity over the photocatalytic hydrogen generation efficiency. The successful synthesis of bimetallic ZIFs (ZnCd-ZIF-8) with the confined loading of a porous nanospace on GO enhances photocatalytic efficiency. The synthesized GO/ZnCd-ZIF-8(10) exhibited exceptional photocatalytic hydrogen generation efficiency of 2.4 mmol g–1 h–1 and AQY of 1.56% in 4 h. The optical and photoelectrochemical studies of the photocatalysts demonstrate the proximity of the catalytic active centers of GO toward water splitting and the Zn-Cd metal centers, with their chemical binding and stabilization, with increased electron–hole separation efficiency and charge transfer over the nanopores. The real-time studies demonstrate that the strong π–π interactions between ZnCd-ZIF-8 and GO are highly efficient toward photoinduced charge separation, confirmed through the Nyquist plot, which demonstrates their easy electron transfer over the hybrid photocatalyst, further leading to effectively enhanced water splitting.