Photoelectrocatalytic hydrogen production on SnS films prepared by chemical bath

Sustainable energy production is urgently needed due to the high environmental costs associated with the use of fossil fuels. Green hydrogen produced by photoelectrocatalysis is an emerging solution for meeting the global energy demand. Herein, we discuss the physicochemical properties and electrochemical hydrogen production of SnS films prepared via chemical bath deposition at 40 °C under visible light. The synthesis times were varied to obtain films with thicknesses of 102, 295, and 495 nm deposited at 3, 4, and 6 h, respectively. All samples were annealed at 400 °C and exhibited an orthorhombic phase. The direct optical bandgap transition decreased from 1.44 to 1.25 eV with increasing sample thickness. With increasing synthesis time, a significant amount of Sn was deposited, forming a surface monolayer of amorphous SnO2, which improved the electronic conductivity of the samples. However, the presence of SnO2 reduced the number of sulfur vacancies, which is crucial for the hydrogen evolution reaction. Therefore, the SnS film synthesized for 3 h exhibited the highest hydrogen evolution rate, which reached 18,826 μmol/m2-h. These results suggest the feasibility of using SnS films for photoelectrochemical hydrogen generation.