Study On Preparation Of Ti/Ni/SnO₂-Sb Catalytic Anodes By Sol-gel Method And Mechanism Of Phenol Degradation

Environment pollution is one of the problems facing humanity in the21st century.Electrochemical catalytic oxidation technology, belonging to the green chemistry, has arousedwide attention because of its operationeasy, no secondary pollution and no selection onorganic pollutants. Ti/Ni/SnO2-Sb2O5anode has high oxygen evolution potential and goodelectrocatalytic activity, however, its practical application is limited due to its shortageelectrode’s service life. For this, the exploration of novel, highly efficient electrochemicalcatalysts, long service life and the catalytic mechanism have become the most importantresearch areas for Electrochemical, Material Science&Technology, and EnvironmentalPollution Control&Renewable Energy Sources. In this dissertation, our work is focused onthe preparation, characterization electrochemical catalytic activities of Ti/Ni/SnO2-Sb2O5anode, and theoretical calculation of phenol degradation. The details are summarized brieflyas follows:Ti/Ni/SnO2-Sb2O5anodes were prepared by sol-gel method to analyze the impact ofprecursor solution and coating thickness. The microstructure and the electrochemicalperformance of coating were analyzed by XRD, SEM, UV-Vis and COD. The resultsshowed that precursor solution and coating thickness have a great influence on themicrostructure and the electrochemical performance of anodes. With the increasing of organicsubstance molecular weight added to precursor solution, the specific surface area and theelectrochemical catalytic activities of anodes increased and the service life of anodesdecreased; and with the increasing of the coating thickness the electrochemical catalyticactivities and the service life increased. The main cause of electrode deactivation mechanismis formation of TiO2insulation layer and detachment of coatings.The influences of methanol, isopropanol and N2, O2, air on degradation rate of phenolwere systematically investigated. It was proved indirectly that the·OH is the main activespecies in aqueous solution under electrochemical catalytic oxidation technology. The GibbsFree Energy of reactant, products and the transition state, that could be used to analyze thedegradation mechanism of phenol,was calculated theoretically by the soft of Gaussian09.Ti/Ni/SnO2-Sb was applied to degradation of the actual industrial wastewater and thecurrent efficiency, power consumption and scope of application were analyzed by the changeof COD. The results showed that electrochemical catalytic oxidation technology is not onlyappropriate to the industrial wastewater with high COD, but also the most promising methodfor treating refractory organics in waste water. During the electrochemical reaction, the current efficiency decreased and the power consumption increased with the decreasing ofCOD for the actual industrial wastewater.