Abstract <p>In this study, an efficient SnO₂ photocatalyst was rapidly synthesized via a simple solid-state reaction method using SnSO₄ and hydrogen peroxide disinfectant (with solid hydrogen peroxide powder as the reactant). The results indicate that the formation of SnO₂ occurs rapidly after heating the mixed powder to approximately 80°C, with a reaction time of approximately 30 s. XRD analysis reveals poorly developed crystal grains with fine sizes. SEM and TEM observations confirmed that the sample was composed of numerous nanocrystallites. Infrared spectroscopy reveals the presence of abundant hydroxyl groups in the sample. XPS characterization confirms the presence of sulfur doping in SnO₂. UV-Vis absorption spectroscopy demonstrates that sulfur-doped SnO₂ exhibited good light absorption in the visible region and a reduction in the bandgap energy. Photoluminescence spectroscopy indicates that sulfur doping increased oxygen vacancies, promoting the separation of photogenerated electrons and holes. The prepared sulfur-doped SnO₂ catalyst exhibited outstanding photocatalytic degradation capabilities. The optimal sample completely degrades methyl orange within 90 min under visible light or 6 minutes under sunlight. Finally, a mechanism for the photocatalytic degradation of methyl orange by sulfur-doped SnO₂ was proposed.</p>