In Situ TiO₂-Decorated SnS₂ Nanoheterostructures for Enhanced Photocatalytic Hydrogen Generation

The synthesis of TiO 2 -decorated SnS 2 nanosheets with varying concentrations of Ti from 5 to 20 mol % (5 mol %, 10 mol %, 15 mol %, and 20 mol %) was carried out, and their several physicochemical and photocatalytic characteristics were investigated. The hydrothermal method was utilized for the in situ synthesis of TiO 2 decorated on SnS 2 hexagonal nanosheets. The XRD indicates the formation of the highly crystalline hexagonal phase of SnS 2 and anatase phase of TiO 2 . Further, the as-prepared TiO 2 –SnS 2 nanophotocatalyst shows absorption behavior in the UV–visible region, and photoluminescence spectra of the TiO 2 –SnS 2 nanostructures show band edge emission along with the peaks attributed to the defects. The formation of hexagonal SnS 2 sheets with uniformly dispersed TiO 2 nanoparticles and SnS 2 nanosheets is confirmed by the FE-SEM and FE-TEM. As TiO 2 loading increased, it was found that the BET surface area also improved. The photocatalytic activity of the synthesized TiO 2 –SnS 2 nanosheets was assessed for hydrogen generation via water reduction under a 400 W mercury vapor lamp as the light source. Among the prepared TiO 2 –SnS 2 nanostructures, the TiO 2 loaded with 15 mol % provides the maximum hydrogen generation, i.e., 2464.9 μmol/0.1gm in 4 h, nearly 2.8 times more than that of pristine SnS 2, i.e., 846.1 μmol/0.1gm. This demonstrates that TiO 2 –SnS 2 could be an auspicious photocatalyst agent for H 2 production via water reduction. Moreover, the photocatalytic activity of the prepared nanostructures is also correlated with the photoconductivity by the photocurrent measurement. Higher the photocurrent, higher is the photocatalytic performance of the prepared nanostructures.