Ti₄O₇多孔膜电极降解橙黄Ⅱ的效果与催化机制

To develop an efficient and low-cost electrochemical oxidation system, a flow-through electrochemical oxidation process was designed based on a Ti₄O₇ porous membrane electrode. The material properties of the Ti₄O₇ porous membrane electrode were analyzed by X-ray diffraction, mercury intrusion, and electron paramagnetic resonance spectroscopy. The degradation kinetics of orange Ⅱ in flow-through and non-flow-through electrochemical oxidation modes were analyzed. The effects of pipeline pressure, current density, initial pollutant concentration, and solution pH on the electrochemical oxidation of orange Ⅱ in the flow-through mode were investigated. The cycling stability of the Ti₄O₇ porous membrane electrode was tested, and the catalytic mechanism of the Ti₄O₇ porous membrane electrode was revealed. Results showed that the Ti₄O₇ porous membrane electrode had high crystal purity, high specific surface area (10.18 m²/g), concentrated pore size distribution (0.1-1.0 μm), and high oxygen evolution potential (2.2 V vs. SHE). The flow-through electrochemical oxidation mode could enhance the liquid-phase mass transfer of pollutants to the electrode surface, accelerating the electrooxidation of pollutants. The degradation rate of orange Ⅱ in flow-through electrochemical oxidation mode was 91.03% and the current efficiency was 88.77%. In the flow-through mode, the pipeline pressure and current density had positive correlation with the degradation rate of orange Ⅱ. Orange Ⅱ with different initial concentrations (10-50 mg/L) could all be effectively degraded in the flow-through electrochemical oxidation mode, with the optimum pH ranging between 3 and 7. The cycling stability of the Ti₄O₇ porous membrane electrode was high. ·OH and SO₄^-· were the main oxidants in the electrochemical oxidation process of Ti₄O₇ porous membrane electrode.