Seamless recovery and reusable photocatalytic activity of CVD grown atomically-thin WS₂ films

Three-atom-thick two-dimensional layered transition metal dichalcogenides (TMDs) has shown appreciable capabilities as materials candidate for photocatalytic applications. In particular, atomically-thin tungsten disulfide (WS₂) has shown attractive interest towards visible-light photocatalytic activity. In this work, we show that the atomically-thin WS₂ films can be used as an effective photocatalyst with Methylene Blue (MB) as a model pollutant, under visible light irradiation. Further, we demonstrate that these WS₂ thin film samples can be recovered effortlessly without losing its chemical and structural stability. The bi-layered WS₂ films yielded a degradation efficiency of ~94% for MB dye. Recovery and reusability of the WS₂ thin films were demonstrated without significant loss in the degradation-efficiency even after 4-cycles of degradation. This study may pave the way for the large-scale degradation and recycling of various effluents using recoverable thin-film photocatalysts.