Co single atom coupled oxygen vacancy on W₁₈O₄₉ nanowires surface to construct asymmetric active site enhanced peroxymonosulfate activation

Enhancing the activation of peroxymonosulfate (PMS) is essential for generating more reactive oxygen species in advanced oxidation process (AOPs). Nevertheless, improving PMS adsorption and expediting interfacial electron transfer to enhance reaction kinetics pose significant challenges. Herein, we construct confined W₁₈O₄₉ nanowires with asymmetric active centers containing Co-Vo-W (Vo: oxygen vacancy). The design incorporates surface-rich Vo and single-atom Co, and the resulting material is employed for PMS activation in water purification. By coupling unsaturated coordinated electrons in Vo with low-valence Co single atoms to construct an the “electron fountainhead”, the adsorption and activation of PMS are enhanced. This results in the generation of more active free radicals (SO₄^•-, •OH, •O₂^-) and non-free radicals (¹O₂) for the decomposition of micropollutants. Thereinto, the degradation rate of bisphenol A (BPA) by Co-W₁₈O₄₉ is 32.6 times faster that of W₁₈O₄₉ monomer, which is also much higher than those of other transition-metal-doped W₁₈O₄₉ composites. This work is expected to help to elucidate the rational design and efficient PMS activation of catalysts with asymmetric active centers. © 2024 Elsevier Inc.