Augmented photocatalysis induced by 1T-MoS2 bridged 2D/2D MgIn2S4@1T/2H-MoS2 Z-scheme heterojunction: mechanistic insights into H2O2 and H2 evolution

Abstract

In the realm of composite photocatalysts, the fusion of the co-catalyst effect with interfacial engineering is recognized as a potent strategy for facilitating the segregation and migration of photo-induced charge carriers. Herein, an innovative mediator-based Z-scheme hybrid, i.e. MIS@1T/2H-MoS₂, has been well designed by pairing MIS with 1T/2H-MoS₂via a facile hydrothermal strategy as a competent photocatalyst for H₂O₂ and H₂ generation. The co-catalyst, i.e. metallic 1T-phase bridging between semiconducting 2H-MoS₂ and MIS, serves as a solid state electron mediator in the heterostructure. Morphological findings revealed the growth of 1T/2H-MoS₂ nanoflowers over MIS microflowers, verifying the close interaction between MIS and 1T/2H-MoS₂. By virtue of accelerated e⁻/h⁺ pair separation and migration efficiency along with a proliferated density of active sites, the MMoS₂-30 photocatalyst yields an optimum H₂O₂ of 35 μmol h⁻¹ and H₂ of 370 μmol h⁻¹ (ACE of 5.9%), which is 3 and 2.7 fold higher than pristine MIS. This obvious enhancement can be attributed to photoluminescence and electrochemical aspects that substantiate the diminished charge transfer resistance along with improved charge carrier separation, representing a good example of a noble metal-free photocatalyst. The proposed Z-scheme charge transfer mechanism is aided by time-resolved photoluminescence (TRPL), XPS, radical trapping experiments, and EPR analysis. Overall, this endeavour provides advanced insights into the architecture of noble metal-free Z-scheme heterostructures, offering promising prospects in photocatalytic applications.