Structural Transformation of SnS2 to SnS by Mo Doping Produces Electro/Photocatalyst for Hydrogen Production.

SnS and SnS2 are layered semiconductors, with potential promising properties for electro- and photocatalytic hydrogen (H2 ) production. The vast knowledge in preparation and modification of layered structures was still not employed successfully in this system to fully maximize its potential. Here, the first report of structural transformation of SnS2 into SnS with Mo-doping as a bifunctional catalyst for the hydrogen evolution reaction (HER) is reported. The structural phase transition optimized the properties of the material, providing a more delicate morphology with additional catalytic sites. The electrochemical studies showed overpotential of 377 mV at 10 mA cm-2 for HER with Tafel slopes of 100 mV dec-1 in 0.5 m H2 SO4 for 10 % Mo-SnS. The same structure acts as an efficient photocatalyst in the generation of H2 from water under visible illumination with rate of 0.136 mmol g-1  h-1 of H2 , which is 20 times higher than pristine SnS2 under visible light.