SnS2-based heterostructures: advances in photocatalytic and gas-sensing applications

Recent advances in tin disulfide (SnS₂)-based heterojunctions have demonstrated their great potential for photocatalysis and sensing applications, owing to their optimal bandgap (2.0–2.3 eV), remarkable stability, environmental compatibility, and outstanding surface reactivity. Despite these advantages, a comprehensive review systematically addressing this emerging field remains lacking. This review first outlines the state-of-the-art synthesis strategies for SnS₂ heterostructures. It then critically evaluates their photocatalytic performance in key applications, including hydrogen evolution, environmental remediation, and hydrogen peroxide production. The gas-sensing capabilities are subsequently analyzed, with special emphasis on nitrogen dioxide and ammonia detection. Mechanistic studies reveal that the enhanced performance originates from tailored heterojunction designs: S-scheme configurations significantly boost charge separation in photocatalysis; n-n/p-n junctions optimize active site distribution and gas adsorption in sensing applications. The interfacial synergy between SnS₂ and coupled semiconductors is identified as the key factor governing performance improvements. Finally, some conclusions and perspectives as well as future challenges are presented.