Abstract

The integration of photocatalysts with cocatalysts is a widely employed strategy to enhance charge separation and transport while providing active sites for accelerated interfacial catalytic reactions. Understanding the structure-performance relationship in doped MoS2 remains challenging, and Re-doped MoS2 alloys as cocatalysts for the degradation of rhodamine B (RhB) dye have not been yet explored. In this study, we employed a 2D TiO2 intercalated with stearic acid (TiSA) composite as a core-shell photocatalytic platform to evaluate the role of rhenium doping in MoS2 nanosheets by fabricating heterojunctions through a simple mechanical mixing synthesis process. The photocatalytic performance of this newly developed Re-doped MoS2/TiSA composite was investigated, leveraging the synergy between activated Re-doped MoS2 nanosheet cocatalysts and TiSA. Optimal photocatalytic performance was achieved with a 10 % Re-doped MoS2 cocatalyst prepared from a precursor mixture with a mole fraction of [Mo]/([Mo]+[Re]) equal to 0.1. This Re loading into MoS2 resulted in the removal of 80 % of RhB within 120 minutes, with a rate constant 3.6 and 1.4 times higher than that of bare TiSA and the undoped MoS2/TiSA, respectively. Experimental results indicate the formation of an n-type doped 2HRexMo1-xS2 polymorphic phase, featuring sulfur vacancies and defects in the otherwise inert basal planes. This structural and electronic modification of the MoS2 layer enables optimal band alignment in the Re-doped MoS2/ TiSA heterojunction, facilitating efficient charge transfer and separation across the interface via a Z-type scheme. The Re-doped MoS2/TiSA n-n heterojunction photocatalyst demonstrated excellent chemical stability and recyclability, maintaining its activity over multiple photocatalytic cycles without significant performance loss, indicating its potential as a promising photocatalyst for developing green technologies.