A new type of photoinduced Anion-Exchange Approach: MOF-Derived Cobalt-Based sulfide enables spatial separation of catalytic sites for efficient H2 photoproduction

Abstract

The high- and low-dimensional cross-structure catalyst enables activating more reaction sites and separates the reduction and oxidation sites in space, thus achieving efficient catalytic reactions. Herein, we develop metal–organic frameworks (MOFs) derivatives with a complete skeleton as high-dimensions cocatalysts under mild conditions. That is, using zeolitic imidazolate frameworks (ZIF-67) as a sacrificial template, a flower-like amorphous CoSx cocatalyst (CoSx-C/N) assembled from two-dimensional (2D) nanosheets rich in C/N is prepared by a new type of photoinduced anion-exchange approach and supported on one-dimensional (1D) Cd0.5Zn0.5S (CZS) catalyst. The formation of unique high- and low-dimensional cross-structure 2D@1D composite photocatalyst (designated as CoSx-C/Ny@CZS). In addition, the Co-S-C/N charge channel is introduced. Such structure can result in both the dispersion of the active sites and an increase in the charge transfer rate. As a result, CoSx-C/N2@CZS has better activity (18.57 mmolg−1h−1) than CZS (7.90 mmolg−1h−1) under visible light irradiation and the quantum yield reaches 21.05% at 420 nm excitation. This work emphasizes utilizing the characteristic of photochemical instability of Co-MOF for cocatalyst design to achieve high photo-charge transfer efficiency and sufficient reaction kinetics, thereby enhancing hydrogen photoproduction performance.