Bi<sub>2</sub>S<sub>3</sub>–In<sub>2</sub>S<sub>3</sub> Heterostructures for Efficient Photoreduction of Highly Toxic Cr<sup>6+</sup> Enabled by Facet‐Coupling and Z‐Scheme Structure
Linjuan Wang, Siva Krishna Karuturi, Ling Zan
Abstract
Abstract The construction of Z‐scheme photocatalyst materials mimicking the natural photosynthesis system provides many advantages, including increased light harvesting, spatially separated reductive and oxidative active sites and strong redox ability. Here, a novel Bi 2 S 3 nanorod@In 2 S 3 nanoparticle heterojunction photocatalyst synthesized through one‐pot hydrothermal method for Cr 6+ reduction is reported. A systematic investigation of the microstructural and compositional characteristics of the heterojunction catalyst confirms an intimate facet coupling between (440) crystal facet of In 2 S 3 and (060) crystal facet of Bi 2 S 3 , which provides a robust heterojunction interface for charge transfer. When tested under visible‐light irradiation, the Bi 2 S 3 –In 2 S 3 heterojunction photocatalyst with 15% Bi 2 S 3 loading content achieves the highest Cr 6+ photoreduction efficiency of nearly 100% with excellent stability, which is among the best‐reported performances for Cr 6+ removal. Further examination using optical, photoelectrochemical, impedance spectroscopy, and electron spin resonance spectroscopy characterizations reveal greatly improved photogenerated charge separation and transfer efficiency, and confirm Z‐scheme electronic structure of the photocatalyst. The Z‐scheme Bi 2 S 3 –In 2 S 3 photocatalyst demonstrated here presents promise for the removal of highly toxic Cr 6+ , and could also be of interest in photocatalytic energy conversion.