Enhanced adsorption and photocatalytic Cr(VI) reduction and sterilization of defective MoS2/PVP.

The exploration of novel nanomaterials to resolve the issues of water pollution with the aid of photocatalytic technology has always been a research hotspot. MoS2 is acknowledged to be one of the promising photocatalysts for its interesting layered structure, suitable band gap, and good chemical stability. However, the fast recombination of photogenerated electrons and holes within the MoS2 impedes its extensive application. Here, hydrophilic polymer (polyvinyl pyrrolidone, PVP) and sulfur vacancy (Vs) are simultaneously introduced into the MoS2 nanosheets to achieve high-efficient photocatalytic hexavalent chromium Cr(VI) removal and antibacterial performance. The incorporation of PVP greatly enhances the adsorption capacity of MoS2, and creating Vs essentially strengthens the photogenerated carrier separation of MoS2. As a result, the Cr(VI) removal efficiency of MoS2-PVP with an appropriate Vs concentration is up to 99.5 % for 3 h. Meanwhile, MoS2-PVP with a relatively higher Vs concentration displays a superior Escherichia coli (E. coli) removal efficiency of 91.8 % within 30 min with the initial E. coli concentration of ∼1.0 × 107 CFU/mL. This study extends photocatalysts to a higher level in designing advanced materials for environmental remediation and establishes a feasible platform for emphasizing the versatility of defect engineering in regulating catalytic activity.