Effect of Size Tuning of Hexagonal SnS2 Nanosheet on the Efficiency of Photocatalytic Degradation Processes

Recent research on SnS₂ materials aims to enhance their photocatalytic efficiency for water pollution remediation through doping and constructing heterojunctions. These methods face challenges in cost-effectiveness and practical scalability. This study synthesizes hexagonal SnS₂ nanosheets of various sizes via a hydrothermal method, assessing their performance in degrading methyl orange (MO) and reducing hexavalent chromium (Cr(VI)). The results show that smaller SnS₂ nanosheets exhibit higher photocatalytic efficiency under sunlight. Specifically, 50 mg of small-sized nanosheets degraded 100 ml of MO (10 mgL^-1) in 30 min and reduced Cr(VI) (10 mgL^-1) in 105 min. The enhanced performance is attributed to: i) an energy bandgap of 2.17 eV suitable for visible light, and ii) more surface sulfur (S) vacancies in smaller nanosheets, which create electronic states near the Fermi level, reducing electron-hole recombination. This study offers a straightforward strategy for improving 2D materials like SnS₂.