Phase-transition-induced defect and valence engineering in Sr/S co-doped W 18 O 49 oxysulfide for efficient NaBH 4 -assisted dark reduction of pollutants

-3 exhibits excellent catalytic durability, broad pH adaptability, and efficient reduction performance toward mixed-pollutant systems in the presence of coexisting ions. This work provides new mechanistic insight into defect-assisted dark catalytic reduction and offers a rational strategy for designing advanced oxysulfide catalysts for environmental remediation.