SnSx/SrTiO3 Nanocomposites for Solar-to-Hydrogen Conversion

Abstract

Large-scale application of direct solar-to-hydrogen technology requires cost-effective and readily available base materials for photocatalysis. Perovskite materials are currently undergoing extensive research aimed at enabling widespread use at a low cost, making compounds like SrTiO₃ promising candidates as base materials for large-scale photocatalysts. In this study, we focused on the hydrothermal synthesis of tin sulfide (SnS_x) embedded on SrTiO₃ to form nanocomposites with varying weight percentages (5%, 10%, 15%, and 20% wt) for photocatalytic hydrogen production. The nanocomposites were characterized using X-ray diffraction and scanning electron microscopy to confirm the formation of SnS_x on SrTiO₃. Photocatalytic hydrogen production experiments were conducted under 4 h of simulated solar illumination. The optimum hydrogen production was achieved with 10% wt SrTiO₃/SnS_x (273.1 μmol g⁻¹ h⁻¹) compared to 54.4 μmol g⁻¹ h⁻¹ for pure SrTiO₃. In contrast, pure tin sulfide showed no photocatalytic activity due to the rapid recombination of photogenerated electrons and holes. Nevertheless, this study clearly demonstrates that tin sulfide can function as a co-catalyst material in the formation of SrTiO₃/SnS_x nanocomposites, enhancing hydrogen production by facilitating electron excitation, increasing the effective surface area of SrTiO₃, and effective photogenerated charge separation. Overall, the results highlight the potential of low-cost, noble-metal-free nanocomposite photocatalysts as promising candidates for efficient solar-to-hydrogen conversion via water splitting, leveraging the chemical versatility of perovskite materials to fine-tune photocatalytic properties.