Morphology Control And Catalytic Oxidation Properties Of Nano-Manganese Oxide Supported Titanium Based Electrocatalytic Membranes

Titanium membrane electrode prepared by thermal decomposition with manganese nitrate in the treatment of refractory organic wastewater shows excellent performance.In this paper,nano-manganese oxide loaded on porous Ti membrane substrate were synthesized by sol-gel method with the manganese acetate to realize the purpose of the green preparation of nano-manganese oxide loaded on Ti membrane without releasing NOx.Manganese acetate sol was prepared by manganese acetate and citric acid.The effects of pH,sintering temperature,sintering time and raw material molar ratio on the crystal structure and morphologies were investigated.Field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),High-resolution transmission electron microscopy(HRTEM)and X-ray diffraction spectrometer(XPS)were employed to analyse the microstructure,crystal structure and electrochemical properties.Nanosphere MnOx/Ti membrane,nanosheet MnOx/Ti membrane and nanorod MnOx/Ti membrane were prepared by sol-gel method.The results showed that nanorod MnOx/Ti membrane performed the best electrochemical properties with electrochemical active area of 378 cm2 and the electron transmission resistance(Rct)was 9.8?.The MnOx/Ti membrane with different morphologies as anode and a stainless steel mesh as a cathode constituted an electrocatalytic membrane reactor(ECMR)was employed to treat the phenol wastewater.Results showed that the COD removal rate of ECMR with nanorod MnOx/Ti membrane was 62.7%under current density of 0.25 mA/cm2 and residence time of 7 min.Under the same condition,the COD removal rate of ECMR prepared by manganese nitrate was 48.9%.The mixture of Mn2O3 and ?-MnO2 were detected after acidification treatment of nanorod MnOx/Ti membrane.The electron transmission resistance between the membrane and the solution was lower than the nanorod MnOx/Ti membrane before acidification treatment.Results showed that the COD removal rate of ECMR was 68.2%under current density of 0.25 mA/cm2 and residence time of 7 min.