Precisely decorating CdS on Zr-MOFs through pore functionalization strategy: A highly efficient photocatalyst for H2 production

Abstract

Different materials, such as metal sulphides, are often combined with metal-organic frameworks (MOFs) to develop multi-functional composites and improve their photocatalytic properties. However, the high interfacial energy barrier limits the formation and nano-assembly of the heterogeneous junctions between MOFs and metal sulphides. Herein, the heterostructured Zr-MOF-S@CdS are successfully constructed through a sequential synthesis method, in which the mesoporous Zr-MOF are firstly decorated with thioglycolic acid through pore functionalization, and followed by the S2- anion exchange process resulting in the surface close attached growth of CdS onto Zr-MOF-S materials. Due to the presence of molecules linkers, the CdS can be precisely decorated onto Zr-MOF-S without aggregation, which can provide more active sites. Moreover, the intimate connections and the suitable band structures between two materials can also facilitate the photogenerated electron-hole pairs separation. Therefore, the resulting Zr-MOF-S@CdS with appropriate ratio exhibits high photocatalytic activity for water reduction, in which the H2 evolution rate can reach up to 1861.7 μmol·g−1·h−1, 4.5 times higher than pure CdS and 2.3 times higher than of Zr-MOF/CdS, respectively. Considering the promising future of MOF-based photocatalysts, this work may provide an avenue for the further design and synthesis MOF-based composite photocatalysts for efficient H2 evolution.