Chemical bath deposition of SnS nanosheet thin films for FTO/SnS/CdS/Pt photocathode

SnS nanosheet thin films were prepared by chemical bath deposition in acidic solution, which used tin (II) chloride dihydrate and thioacetamide as precursors of Sn and S, respectively. The influences of pH levels, precursors' mole ratios, deposition times on the physical properties of SnS nanosheet thin films were investigated. The sheet-like morphologies and compositions of as-deposited SnS thin film were characterized by Scanning electron microscope (SEM). X-ray diffraction (XRD), Raman and X-ray photoelectron spectra (XPS) were used to confirm the crystal structures and phase purities of SnS nanosheet thin films. When employed as a photocathode for photo-electrochemical (PEC) solar hydrogen production, the as-deposited SnS nanosheet thin films yielded photocurrent densities of 31.94 μA cm−2 at −0.4 V under illumination of AM 1.5G. After deposition of CdS and Pt layers, the cathodic photocurrent densities of FTO/SnS/CdS/Pt and FTO/annealed SnS/CdS/Pt were improved to 0.572 mA cm−2 and 0.702 mA cm−2, respectively, which demonstrated the great potential of using earth-abundant SnS for efficient hydrogen production.