Bimetallic zeolite-imidazole framework-based heterostructure with enhanced photocatalytic hydrogen production activity†

Abstract

Bimetallic zeolite-imidazole frameworks with controllable flat band position, band gap and hydrogen evolution reaction characteristics were adopted as a photocatalytic hydrogen production catalyst. Furthermore, the g-C ₃N ₄–MoS ₂ 2D–2D surface heterostructure was introduced to the ZnM-ZIF to facilitate the separation as well as utilization efficiency of the photo-exited charge carriers in the ZnM-ZIFs. On the other hand, the ZnM-ZIFs not only inhibited the aggregation of the g-C ₃N ₄–MoS ₂ heterostructure, but also improved the separation and transport efficiency of charge carriers in g-C ₃N ₄–MoS ₂. Consequently, the optimal g-C ₃N ₄–MoS ₂–ZnNi-ZIF exhibited an extraordinary photocatalytic hydrogen evolution activity 214.4, 37.5, and 3.7 times larger than that of the pristine g-C ₃N ₄, g-C ₃N ₄–ZnNi-ZIF and g-C ₃N ₄–MoS ₂, respectively, and exhibited a H ₂-evolution performance of 77.8 μmol h ⁻¹ g ⁻¹ under UV-Vis light irradiation coupled with oxidation of H ₂O into H ₂O ₂. This work will furnish a new MOF candidate for photocatalysis and provide insight into better utilization of porous MOF-based heterostructures for hydrogen production from pure water.

Abstract

The g-C ₃N ₄-MoS ₂ could facilitate the separation as well as utilization efficiency of the photo-generated charge carriers in the ZnM-ZIFs, and hence improved the photocatalytic H ₂ production with and without sacrificial agent.