Ti₄O₇ 阳极材料制备改性及其在电化学水处理中的应用研究进展

With the rapid development of China′s industry，water pollution in various fields is becoming more and more serious. Traditional water treatment methods have been difficult to meet the environmental requirements. Electrochemical water treatment technology，as an effective means to build a "carbon neutral" water treatment technology model and realize green development of water treatment technology，has developed rapidly in recent years. Among them，electro catalytic oxidation technology，as one of electrochemical water treatment technologies，directly degrades organic pollutants by electrode reaction under the action of external electric field，or degrades organic pollutants by using electrodes to generate a large number of strong oxidizing free radicals. This technology is mainly aimed at organic wastewater with high concentration，difficult biodegradation and high toxicity，and has the advantages of green，safety，high efficiency，low energy consumption，small secondary pollution，etc. As the core of electro catalytic oxidation technology，the selection of anode is very important. Common electrodes such as carbon，precious metals and titanium based metal oxides have defects such as high cost，poor stability and weak catalytic ability. For example，metal electrodes and titanium based metal oxide electrodes have surface metal element dissolution，causing certain potential safety hazards；the catalytic performance of carbon electrode fluctuates greatly，and the yield of hydroxyl radicals on the surface of Sb/SnO₂ electrodes and Ir/Ru/Ta electrodes are not high，so the catalytic ability needs to be improved The preparation cost of precious metal electrode and boron doped diamond electrode is high，which is not conducive to large-scale use economically. Therefore，it is imperative to develop new anode materials. The research showed that titanium sub-oxide materials had unique physical and electrochemical properties such as high conductivity，superior chemical stability，wide electrochemical stability potential window，etc. Among them，Ti₄O₇ materials had the best conductivity，which could reach 1500 S·cm^-1，about twice the conductivity of graphite（727 S·cm^-1）. Compared with the above materials，Ti₄O₇ electrodes could meet the increasingly complex requirements of industrial organic wastewater treatment in terms of safety，catalysis，economy，stability，etc. In order to further promote the application，this review introduced the structural properties and physical and chemical properties of sub-oxide anode materials. According to the classification of in-situ and ex-situ，the preparation methods of Ti₄O₇ powder electrodes were summarized，and the advantages and disadvantages of coated electrodes，integrated electrodes and composite electrodes and their application scenarios were analyzed. In addition，the research progress of Ti₄O₇ anodes used in different electrochemical water treatment fields was summarized，and the application of Ti₄O₇ anodes in electrocatalytic oxidation wastewater treatment field was mainly introduced. Magnéli phase titanium sub-oxide electrode played a very important role in the degradation of different kinds of target pollutants and the mixing of actual wastewater. Coupling with different processing technologies could also achieve better processing effect. On the basis of summarizing the existing work，this review also pointed out the current technical difficulties，and put forward the future research direction in process optimization，material modification and application expansion. It was worth noting that Magnéli phase titanium suboxides had played very important roles in organic degradation，and there was no doubt that titanium sub-oxides would become indispensable materials in the future.