Activated H2O2 on Ag/SiO2-SrWO4 surface for enhanced dark and visible-light removal of methylene blue and p-nitrophenol

Activated H2O2 on the surface of nanostructures for advanced oxidation process attracts the interest for energy consumption, time saving rather than Fenton reaction process. Here, we introduce Ag/SiO2 NPs immobilized on SrWO4 surface for enhanced catalytic and photocatalytic oxidation of methylene blue and reduction of p-nitrophenol by H2O2 surface activation. Both theoretical calculations (rwb97xd/LANL2DZ) and experimental (FT-IR and XRD) show that the catalytic enhancement was due to the surface interaction between Ag/SiO2 and SrWO4 that activate H2O2 surface molecules in absence of light. The photocatalytic enhancement was interpreted by the hot electrons ejected from Ag NPs to the SrWO4 rather than the p-n junction created by Ag/SiO2 and SrWO4 mechanism. Different spectroscopic techniques such as SEM, TEM, XRD were used for the catalysts characterizations. The optical measurements such as UV-Vis and photoluminescence were incorporated to further support the mechanism. The catalyst posses high catalytic activity over wide pH range (4-10). (C) 2020 Elsevier B.V. All rights reserved.