Two dimensional S-scheme Bi2WO6-TiO2-Ti3C2 nanocomposites for efficient degradation of organic pollutants under natural sunlight

Two-dimensional (2D) materials have fascinated the researchers to exploit their properties including large sur-face area, ability to act as a support and to form face-to-face interfacial contact with other 2D materials for fabricating efficient photocatalytic materials. In this work, Bi2WO6, TiO2 and Ti3C2 nanosheets have been used synthesizing different series of binary Bi2WO6-TiO2 and ternary Bi2WO6-TiO2-Ti3C2 2D nanocomposites by an electrostatic self-assembly synthesis route. The as-prepared pristine materials and binary and ternary nano -composites were characterized by different structural, morphological and compositional characterization tech-niques to confirm their successful synthesis and 2D morphology. It was found that the optimized Bi2WO6-TiO2 (20 wt%) and Bi2WO6-TiO2 (20 wt%)-Ti3C2 (5 wt%) nanocomposites showed 97.0% and 98.5% degradation of methyl green in 80 min and 40 min, respectively, which was higher than their pristine counterparts. The enhanced activity was credited to the large surface area offered by 2D nanocomposites, pollutant adsorption and enhanced photogenerated charge separation and transfer facilitated by S-scheme mechanism and face-to-face interfacial contact of different components of these nanocomposites. This work delivers an example of highly efficient 2D nanocomposites and discusses the role of Ti3C2 as an electron acceptor in S-scheme photocatalytic system.

Automated summary

In this study, binary and ternary nanocomposites were synthesized using Bi2WO6, TiO2, and Ti3C2 nanosheets by electrostatic self-assembly. The optimized nanocomposites showed enhanced photocatalytic activity for the degradation of methyl green.