Preparation And Electrocatalytic Properties Of MNOX/SB-SNO2/TI Composite Electrode Films

The phenolic wastewater has been one of the important factors which are restricting the development of our country's economy.Sb-SnO₂ coating was prepared by polymer precursor method to modify the tubular porous Ti membrane,and MnO_x/Sb-SnO₂/Ti composite electrode membrane was prepared by sol-gel method.A functional electrocatalytic membrane reactor?ECMR?,which assembled by MnO_x/Sb-SnO₂/Ti composite membrane electrode as anode and a stainless steel mesh as cathode,has been employed for industrial wastewater treatment in this study.MnO_x sol was prepared by sol-gel method,and loaded on the Ti membrane by dip coating method,after heat treatment,Mn₂O₃ and Mn₃O₄ who have excellent catalytic performance were identified on the surface of electrocatalytic membrane.The electrochemical and electrocatalytic properties of MnO,/Ti composite electro-catalytic membrane were superior to the original Ti membrane.In the process of phenolic wastewater treatment,under the conditions of 450 mg/L phenolic wastewater?500 mL?,pH of 7,current density of 0.9 mA/cm² and residence time of 15 min,the achieved phenol,COD and TOC removal rate of ECMR with MnO_x/Ti membrane were 95.89%,84.38%and 76.73%,increased by 36%,32.24%and 33.57%,respectively,compared with the original Ti film.While energy consumption,from 0.66 kWh/KgCOD to 0.41 kWh/KgCOD,was reduced by 37.88%.The Sb-SnO₂ was prepared by polymer precursor method to modified the Ti membrane substrate,and then loaded MnO_x catalyst on the Sb-SnO₂/Ti composite membrane by sol-gel-dip coating-thermal decomposition method to make the MnO_x/Sb-SnO₂/Ti composite electrode membrane.The specific surface area of the the MnO_x/Sb-SnO₂/Ti composite electrode membrane has been increased because of the preparing of the Sb-SnO₂ interlayer.At the same time the new crystal form?Sb2O3,Sb2O5 and SnO₂?and solid solution?MnSnO₄,Sn4SbO8,SnTiO₄ and MnSb2O6?were identified in MnO_x/Sb-SnO₂/Ti composite electrode membrane.The presence of solid solution is beneficial to improve the electrochemical performance of the composite electrode membrane.The ECMR with MnO_x/Sb-SnO₂/Ti composite electrode membrane as anode was assembled to employ for phenolic wastewater treatment.The effects of some main parameters such as the thickness of Sb-SnO₂ interlayer,current density and pH on the performance of the ECMR were investigated.During the ECMR operation under the conditions of Na2SO₄ electrolyte concentration of 15 g/L?500 mL?,phenol initial concentration of 450 mg/L?500 mL?,current density of 0.9 mA/cm²,residence time of 15 min,Sb-SnO₂ loading amount of 3.4 wt%,and neutral or weak acid for processing environment,the MnO_x/Sb-SnO₂/Ti composite electrode membrane showed the optimal electrocatalytic performance,and the achieved phenol,COD and TOC removal rate were 98.98%?89.38%and 82.97%,respectively.While energy consumption,from 0.41 kWh/KgCOD to 0.28 kWh/KgCOD,was reduced by 31.71%,comparing with the ECMR with MnO_x/Ti as the anode.