Mesoporous manganese dioxide prepared by nano-casting: An efficient catalyst for of methyl orange and oxalic acid degradation in aqueous solution

Abstract

In the present study, mesoporous manganese dioxide catalysts with large high specific surface area, pore volume and large pore size structure were synthesised using the nano-casting method with a mesoporous structure of silica SBA-15 as a hard template. Therefore, the physical and chemical properties of mesoporous MnO2 were characterised by XRD, FT-IR, Raman, UV–Vis, N2 adsorption-desorption, SEM, EDS, TEM, TG and XPS. In this study, the oxidative reactivity of MnO2 corresponding to methyl orange (MO) and oxalic acid (OA) was assessed. MnO2 was found to contain the most abundant oxygen vacancies and easily reducible surface adsorbed oxygen (Olatt), which facilitates the catalytic utilisation of ozone. As a result, the highest catalytic performance was achieved for methyl orange and oxalic acid, with degradation efficiencies of 98.37% and 92.96%. This present study deepens our understanding of manganese dioxide catalyzed ozone and provides a reference for improving process efficiency.