Enhanced Photocatalytic Activity of Cs₄PbBr₆/WS₂ Hybrid Nanocomposite

Photocatalytic processes are among the prime means for mitigating the pollution caused by toxic effluents. In this context, photocatalysis presents a promising path and is undergoing rapid evolution. Halide perovskite-nanocrystals (HP-NCs) are excellent candidates due to their negative conduction band minimum and low work function, essential for photocatalysis. Yet, HP-NCs face limitations within this domain because they are prone to chemical degradation when exposed to external factors like high temperature, polar solvents, oxygen, and light. A practical approach toward stabilizing HP-NCs involves hybridizing them with a chemically inert material that can provide steric stabilization and act as a cocatalyst. Transition-metal dichalcogenides emerge as outstanding candidates to sterically stabilize the HPs as they are stable, chemically inert, and can serve as co-catalysts, enabling suppressed charge recombination. Herein, the photocatalytic performance of Cs₄PbBr₆/WS₂-nanocomposites towards organic dye degradation in polar solvents under visible light illumination is investigated. We found that the presence of WS₂ nanostructures significantly stabilizes the HP-NCs and promotes dye degradation rate compared to pristine Cs₄PbBr₆-NCs. Using transient absorption measurements, we found that the WS₂-nanostructures act as an electron transport channel, effectively reducing charge recombination in the NCs. These findings pave the way for implementing Cs₄PbBr₆/WS₂-nanocomposites as stable and superior photocatalysts.