Enhanced Photoelectrocatalytic Degradation Of Benzotriazole By Composite Metal Oxides

Benzotriazole（BTA）is a nitrogen-containing organic pollutant that is often found in beneficiation wastewater and airport discharge effluent.The substance has the characteristic of being highly hazardous at low concentrations,and when it enters the natural environment,it will pose a threat to plant,animal,and human health.Photoelectrocatalytic oxidation（PEC）has always been a research hotspot in the field of difficult-to-degrade organic wastewater treatment because of its unique advantages of high efficiency and sensitivity,and the key to its practical application is to develop new catalysts that are green,efficient and low-cost.In this thesis,an inexpensive composite metal oxide material was prepared,and its effect as a catalytic material to enhance the degradation of PEC by BTA was examined,and its degradation mechanism was discussed.Firstly,Fe₂O₃/Cu₂O（FC）photoelectrocatalytic materials were successfully prepared by a pot of hydrothermal method.The physicochemical properties were characterized by SEM,XRD and XPS,and the results showed that Fe₂O₃ with a small disc structure was successfully loaded on Cu₂O with cubic structure,so that FC had better photoelectrocatalytic performance than single Fe₂O₃ and Cu₂O for PEC catalytic degradation of BTA.When the compound ratio of FC was 2:1,the p H value was 3.06,the catalyst dosing amount was 0.05g/L,and the degradation time was 60 min,the removal rate of FC-enhanced photoelectrocatalytic degradation of BTA was 99.95%,and the degradation process of FC-enhanced PEC on BTA was in line with the first-level kinetic model.Secondly,in order to further improve the degradation effect of BTA.Sn O₂ was introduced into the preparation of FC to further improved its oxygen evolution potential and oxygen deficiencies,and the composite material Sn O₂/Fe₂O₃/Cu₂O（SFC）was prepared.Through material characterization and experimental results,it can be seen that SFC has a more uniform distribution of active sites than FC,which is conducive to efficient degradation of BTA in water.At the p H was 6.68,the dosage was 0.09g/L,and the time was 40min,the degradation effect was the best,and the removal rate of SFC to BTA reaches 99.89%,and the repeatability experiment showd that the removal rate can still reach more than 99.27%after 5 SFC cycles,which proved that it has good recyclability.The experimental conditions for SFC to enhance PEC degradation of BTA were more neutral than FC,the removal efficiency was higher,the energy consumption was 0.11 k W·h lower than that of FC,and it was greener and more environmentally friendly.Finally,the reaction mechanism of PEC degradation of BTA by two materials was explored.Through PL,UV-Vis and i-t curve analysis,the main mechanism of FC and SFC enhanced PEC degradation of BTA was verified:the composite materials produced hydroxyl radicals under the action of ultraviolet light and electricity（·OH）,superoxide radicals（·O₂^-）and holes（h⁺）,FC was the oxidative degradation of BTA by the combination of the three,while SFC was dominated by holes,supplemented by two other free radicals.The possible degradation pathways of BTA in FC-enhanced PEC were inferred by liquid chromatography-mass spectrometry,UV full-spectrum scanning,and COD monitoring and analysis.In summary,the results of this study can provide new technical support and theoretical basis for for the effective treatment of BTA-containing wastewater.