Adopting sulfur-atom sharing strategy to construct CoS2/MoS2 heterostructure on three-dimensional nitrogen-doped graphene aerogels: A novel photocatalyst for wastewater treatment

Abstract

One of the significant challenges arising from the design of the structure of photocatalytic materials lies in the control over how the photogenerated electrons and hole pairs on semiconductors are re-combined to accelerate the surface catalytic reaction. In this work, the bottom-up approach is applied to design three-dimensional (3D) CoS2/MoS2-nitrogen-doped graphene aerogel (CoS2/MoS2-NGA) photocatalyst, where a large number of small-sized ultra-thin MoS2 nanosheets are connected to CoS2 nanoparticles by means of sulfur-atoms (S-atoms) sharing, and covered on the CoS2 surface uniformly. The chemical bonding between the CoS2 and MoS2 completely restricts the aggregation of nanoscale MoS2 so as to expose more edge active sites. In the meantime, it is demonstrated that CoS2 plays a critical role in accelerating charge separation at the heterojunction interface and in preventing electron-hole recombination. As indicated by the results, CoS2/MoS2-NGA possesses excellent photocatalytic properties and high cycle stability when applied for the photodegradation of organic pollutants, which provides a potential solution to the treatment of wastewater in practice.