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 SO-4· were the main oxidants in the electrochemical oxidation process of Ti4O7 porous membrane electrode.