Surface oxygen vacancies induced peroxidase-like activity for W₁₈O₄₉ nanospheres and their application in degradation of methylene blue

In this paper, the W₁₈O₄₉ nanospheres (W₁₈O₄₉ NSs) with diameter about 100 nm have been found to exhibit intrinsic peroxidase-like activity, which can catalytically oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) by H₂O₂ to produce a color reaction. Different from the catalytic behavior of the Fe₃O₄ particles, the possible catalysis mechanism was notably dependent on the surface oxygen vacancies (SOVs) abundant in W₁₈O₄₉ NSs, which served as important catalytic sites. Moreover, due to the speciality with high surface area (136.13 m² g⁻¹) and negative potential (− 54.8 mV), the obtained W₁₈O₄₉ NSs could be used as efficient peroxidase mimetic to remove the dye pollutant methylene blue (MB) in the assistance of H₂O₂. And the degradation efficiency of MB could be achieved above 91% with 50 μg mL⁻¹ W₁₈O₄₉ NSs. .