Heterovalent State and Oxygen Vacancy Defect Structure‐Associated V/S Co‐Doped SnO₂ for Catalytic Reduction of Organic and Cr⁶⁺ Pollutants in the Dark

V/S co‐doped SnO 2 bimetal sulfur‐oxides catalysts labeled as (Sn,V) 1‐ x (S,O) 2‐ y or (SnVSO) with heterovalent state and oxygen vacancy defect are prepared via a green and facile method. The presence of SnVSO in the heterovalent states of Sn 4+ /Sn 2+ and V 5+ /V 4+ facilitates the rapid transfer of the electrons. It improves the electronic charge lifetime, accelerating the efficiency of the catalytic reduction of pollutants. The V/S co‐doped SnO 2 regulates the bandgap energy structure. The hydrazine adjusts the heterovalent metal states to reduce Sn 4+ to Sn 2+ and V 5+ to V 4+ . Also, it introduces oxygen vacancies to SnVSO to maintain the charge equilibrium and increase the active surface reactive sites, which enhance the catalytic activity. The SnVSO‐3 prepared with 0.4 mL hydrazine exhibits excellent catalytic activity, which wholly reduces 20 ppm of 100 mL methyl orange (MO), rhodamine B (RhB), methylene blue (MB), hexavalent chromium (Cr 6+ ), and 4‐nitrophenol (4‐NP) within 6 min. In addition, the SnVSO‐3 also has good stability after repeated 6 runs with a reduction efficiency of 96.8%. Therefore, the V/S co‐doped SnO 2 sulfur oxide catalysts have a promising potential for reducing Cr 6+ and organic pollutants.