Non-radical activation of HO by surface-disordered WO for efficient and selective pollutant degradation with weak matrix effects.

Heterogeneous catalysis is promising for water treatment. Solid catalysts play governing roles. Herein, the surface-disordered WO, D-WO, engineered with surface and sub-surface defective sites from NaBH reduction was proven to be an effective catalyst for HO activation. The defective degree and defects amount on WO were regulated by NaBH. More than 95% of two typical azo dyes, RhB and MG, were selectively degraded in D-WO/HO system during 3.0 h, while no significant activity was observed for MO as well as bisphenol A, roxarsone, phenol, 4-chlorophenol, p-nitrophenol, o-aminophenol, urea, and 2,4-dichlorophenol in comparison under the identical conditions (mainly less than 20%). Both ESR and radical scavenging tests indicated the minor role of ·OH from HO activation on D-WO. The superior activity of D-WO could be mainly attributed to the surface and sub-surface defects with finely tailored local atomic configurations and electronic structures of central metal sites. Surface and sub-surface defective sites could serve as the reactive sites of interfacial adsorption, dissociative activation, and catalytic decomposition for both oxidant and pollutants, with high adsorption energy, strong structural activation, and superior catalytic activity. Our findings provided a new chance for non-selective radical catalysis based on transition metal oxides and a promising catalyst with high performance, low cost, and no toxicity for pollutant degradation with weak matrix effects in wastewater and surface water.