Enhanced photocatalytic hydrogen production on tin disulfide self-assembled from ultrathin sheets with sulfur vacancies generated by doping indium ions.

In consideration of comparable ionic radius between indium ions and tin ions, indium-doped SnS₂ (In/SnS₂) sample was designed and synthesized by one-pot solvothermal method. Its multi-level structure composed of 10-nm-thick ultrathin sheets can enhance utilization efficiency of solar light. The substitution of trivalent indium ions for tetravalent tin ions causes indium to form a negative charge center and simultaneously produces sulfur vacancies positively charged. As expected, the production of hydrogen on doped sample is up to 470 µmol g⁻¹, which is about twice as high as that on SnS₂. This is attributed to hierarchical structure composed of ultrathin sheets and effective attraction of hydrogen ions by negative charge on trivalent indium ions. The results suggest that doping the ions whose ionic radius is close to the radius of the anions or cations in the material into the lattice sites may provide a new tactic for the design of semiconductor photocatalytic materials. [ABSTRACT FROM AUTHOR]