钛合金表面铁氧化物膜层类Fenton催化剂制备及降解苯酚性能

摘要

采用微弧氧化法在硅酸盐电解液体系中于钛合金表面成功制备了铁氧化物膜层类Fenton催化剂.采用SEM、XRD以及XPS对所得膜层的表面形貌、晶体结构及物相组成进行表征,发现膜层中含有金红石相TiO2(R-TiO2),和非晶态的铁氧化物Fe3O4;对膜层的表面形貌分析发现电解液中加入铁氰化钾后表面粗糙度及平均孔尺寸增大.以苯酚作为目标降解物,研究了膜层类Fenton催化活性,同时研究了铁源含量、苯酚浓度、H2O2投料量以及pH值对膜层降解苯酚效率的影响,优化了降解条件,研究发现在pH 3.0、温度30℃、H2O2 6.0 mmol·L-1、苯酚35 mg·L-1及铁氰化钾含量10 g·L-1的条件下降解90 min,苯酚降解效率可达90％.通过对不同温度下降解苯酚的反应动力学研究,利用阿伦尼乌斯方程得到了该膜层类Fenton降解苯酚的反应活化能E为96.9 kJ·mol-1.最后,评价了膜层的稳定性并分析了稳定性衰减的原因.%The iron oxide coating Fenton-like catalyst on Ti alloy was successfully prepared in silicate electrolyte via micro-arc oxidation.The surface morphology,crystal structure and phase composition were studied by SEM,XRD and XPS.The results indicated that the as-prepared coating included the rutile TiO2 (R-TiO2),and amorphous Fe3O4 which was analyzed by XPS.The SEM images suggested that after the addition of K3[Fe(CN)6] in the electrolyte,the surface roughness and average pore size of the as-prepared coating were increased.The Fentonlike catalytic activity of as-prepared coating was investigated by degradation of phenol.What's more,the influences of K3[Fe(CN)6] content,phenol concentration,H2O2 dosage and pH value on phenol degradation were also studied and finally the optimal degradation condition was confirmed.Under pH 3.0,30 ℃,H2O2 6.0 mmol·L-1,phenol 35 mg·L-1 and K3[Fe(CN)6] 10 g·L-1,90％ phenol could be removed.The effect of degradation temperature on degradation efficiency was also evaluated and the reaction kinetics under different temperature were also studied.The activation energy of Fenton-like degradation of phenol through Arrhenius equation is 96.9 kJ· mol-1.Finally,the stability was studied and the stability degradation was also analyzed.