以辊压法制备了炭黑-聚四氟乙烯(PTFE)空气阴极,并与传统涂刷法制备的空气阴极作了性能对比,并优化了该电极产双氧水的主要影响因素。结果表明,辊压法制备阴极工艺中,以炭黑和PTFE质量比为1.5:1的空气扩散电极性能为佳,且优于涂刷法制备的空气阴极。在p H=7的Na2SO4(浓度0.1 mol/L)、空气体积流量0.6L/min、电流150 m A时,2 h后该阴极产H2O2质量浓度可达589 mg/L;且性能稳定,经过10次使用后H2O2的质量浓度仍保持在420 mg/L。进一步以质量浓度50 mg/L的甲基橙为模拟污染物,电芬顿处理10 min其脱色率可达97%,使用10次后其脱色率仍达92.8%。该空气扩散电极H2O2产率高、p H适用范围广(3~9),可望应用于水中污染物的电芬顿处理。
A carbon black/PTFE air cathode was prepared by rolling, and its electrochemical performance was compared with that prepared by traditional brushing. The main influencing factors for hydrogen peroxide production by this electrode were optimized. The results showed that in the process of cathode preparation by rolling, air cathode with the mass ratio of carbon black to PTFE being 1.5:1 performed better than brushing air cathode. And when p H=7, Na2SO4 concentration was 0.1 mol/L, air volume flow rate was 0.6 L/min, and current was 150 m A, mass concentration of hydrogen peroxide could reach 589 mg/L after 2 h. The performance was stable, and after 10 times cycle, mass concentration of H2O2 remained 420 mg/L above. With mass concentration of 50 mg/L methyl orange as simulated pollutant, the de-colorization by electro-Fenton reached 97% in 10 min, which remained 92.8%even after 10 times reuse. The air diffusion electrode possessed high H2O2 yield under wide p H range of 3~9, and thus it was promising to be applied in pollutants degradation by electro-Fenton.