Synthesis of Submicron Hexagonal Plate-Type SnS2and Band Gap-Tuned Sn1−xTixS2Materials and Their Hydrogen Production Abilities on Methanol/Water Photosplitting

Abstract

SnS2and Sn1−xTixS2(x= 0, 0.1, 0.3, 0.5, and 0.7 mol) materials were designed using solvothermal method with the aim to enhance hydrogen production from water/methanol water photosplitting. Scanning electron microscopy revealed hexagonal plates with one side, 3.0 μm in length, in the SnS2materials. Pure SnS2showed absorption band edges of above 660 nm, and the absorption was shifted to low wavelengths with the insertion of Ti ions. The evolution of H2from MeOH/H2O (1 : 1) photosplitting over SnS2hexagonal plates in the photocatalytic liquid system was 0.016 mL h−1 g−1, and the evolutions were enhanced in Sn1−xTixS2. In particular, 0.049 mL h−1 g−1of H2gas was produced in Sn0.7Ti0.3S2without electrolytes and it increased significantly to more than 90.6% (0.47 mL h−1 g−1evolutions) at higher pH using 0.1 M of KOH. Based on the UV-visible absorption spectra, the high photocatalytic activity of Sn1−xTixS2was attributed to the existence of an appropriate band-gap state that retarded recombination between the electrons and holes.