Novel C fibers@MoS2 nanoplates core-shell composite for efficient solar-driven photocatalytic degradation of Cr(VI) and RhB

As a green and efficient strategy for wastewater treatment, solar-driven photocatalysis has received great attention in recent years, in which graphene-like semiconductor MoS₂ has been considered as a promising photocatalyst due to its strong absorption on visible light originating from its narrow band-gap. But the poor photocatalytic activity resulted from the strong recombination of photogenerated electron-hole pairs severely limits the practical application of MoS₂ photocatalysts. In this work, we report a novel C fibers@MoS₂ nanoplates core-shell composite prepared by a simple, one-step thermal evaporation method, in which numerous MoS₂ thin nanoplates are in-situ, densely and even vertically grown on the surface of the C fibers. Such composite exhibits superior solar-driven photocatalytic activity and excellent stability for degrading environmental pollutants like inorganic Cr(VI) and organic rhodamine B. In comparison with the commercially available MoS₂ powder, the as-prepared composite shows an increased reaction rate constant by a factor of approximately 7.0 for the photocatalytic reduction of Cr(VI) and about 2.6 for the photodegradation of rhodamine B under simulated sunlight irradiation. The enhanced performance of this composite could be attributed to the improved efficient separation of photogenerated electron-hole pairs and fast transfer of charge carriers caused by the highly conductive C fibers.