Additive-free hydrothermal synthesis of SnS2 nanostructures and its enhanced photocatalytic and photoelectrochemical performance under visible solar light

Tin (IV) sulfide (SnS₂) is an inexpensive direct band gap semiconductor and layered structure with great potential in photovoltaic and photocatalytic applications. Among other sulfides of tin (e.g., SnS, Sn₂S₃ etc.), SnS₂ is thermodynamically more stable than others. However, the development of the cost-effective, high-yield, and additive-free synthesis of SnS₂ nanostructures with enriched photocatalytic properties remains a challenge. Herein, we report the additive-free hydrothermal synthesis of SnS₂ nanosheets in a non-aqueous medium. The nanostructures and film grown on FTO substrate were annealed at 250°C in a nitrogen atmosphere to obtain more compact and highly crystalline nanosheets. The photocatalytic performance of the nanostructures is evaluated by the photo-degradation of Methylene Blue dye under simulated solar light. A 98 % dye degradation is achieved within 60 min under solar visible light with 5 mg/ 50 ml SnS₂ photocatalyst present in the dispersion. The enhanced photocatalytic activities of the annealed SnS₂ nanostructures are attributed to their novel quasi-two-dimensional morphologies and superior semiconducting properties tuned by thermal treatment.