Enhancement of Z-scheme behavior by coupling local WO3−x–WS2 with Au nanoparticles for efficient photoelectrochemical degradation of methylene blue

Abstract

The removal of water pollutants has become the foremost priority in environmental remediation. To overcome this issue, photoelectrochemical (PEC) organic-dye degradation is preferred as it meets the demands of sustainability and eco-friendliness. For efficiently harvesting solar energy and facilitating carrier migration, semiconductors with appropriate band gaps, high light absorption capacity, and favorable reaction kinetics have been explored to drive PEC organic-dye conversion. In this work, we prepared a WO_3−x–WS₂ heterostructure embedded with Au nanoparticles by hydrothermal and photodeposition strategies. The optimal WO_3−x@Au–WS₂ ternary catalyst achieved the removal of 98.52% methylene blue in a neutral aqueous solution within 60 min under visible light, which was 1.7 times higher than that of bare WO_3−x. In the WO_3−x@Au–WS₂ ternary heterostructure, a Z-scheme of electron transfer paths was formed to promote the migration of photogenerated carriers. Our study offers new insights into the catalytic mechanism of ternary heterostructures, providing a promising strategy for improving the efficiency of wastewater treatment.