In-situ synthesis of structurally oriented hierarchical UiO-66(–NH2)/CdIn2S4/CaIn2S4 heterostructure with dual S-scheme engineering for photocatalytic renewable H2 production and asulam degradation

Abstract

The in-situ fabrication of dual S-scheme ternary heterostructure is a promising approach to isolate photo-induced electron-hole and boost the efficiency of a semiconductor photocatalyst. However, the dual S-scheme heterostructure based on MOFs are rarely narrated. Herein, a S-vacancy rich hierarchical UiO-66(–NH2)/CdIn2S4/CaIn2S4 ternary hybrid material is successfully fabricated by in-situ preferential growth of ultrathin CaIn2S4 nanosheets and CdIn2S4 nanorods in presence of UiO-66(–NH2) (UN) spherical nanoparticles by using a simple reflux route. The physiochemical characteristics and optoelectronic features of the developed materials are illustrated in detail. The efficacy of UiO-66(–NH2)/CdIn2S4/CaIn2S4 ternary hybrid material is explored for photocatalytic H2 evolution reaction and decontamination of asulam (ASM) herbicide. The development of S-vacancy facilitates interfacial charge carrier migration and reduces the recombination rate. The enhanced photocatalytic H2 production and ASM degradation could be ascribed to staggered band alignment between UiO-66(–NH2) (UN), CdIn2S4 (CDS) and CaIn2S4 (CAS), which support S-scheme charge channelization in the heterojunction. Due to its physio-chemical advantages, the optimal 15UN/CDS/CAS30 hybrid photocatalyst exhibits highest photocatalytic H2 evolution rate of 4931 μmol g−1h−1 with apparent conversion efficiency of 31.5% and ASM degradation > 93% (k = 0.02 min−1) under irradiation of visible light. This work furnishes a new perceptive into the in-situ construction of dual S-scheme photocatalytic systems for renewable energy production and decontamination of organic pollutants. In addition, this study for the first time illustrates mineralization of Asulam using a heterogeneous photocatalytic route.