中文摘要：

以纳米α-Fe2O3和草酸在500W汞灯照射下构成了光化学类Fenton体系,并研究在此体系中甲基橙溶液的异相光催化降解行为。考察了草酸的初始浓度对纳米α-Fe_2O_3和光催化体系对甲基橙催化反应效率的影响,同时为探究该光催化反应过程的机理,对反应过程中溶液pH、Fe^2＋的浓度进行了检测。结果表明,草酸能显著促进甲基橙的脱色与降解,甲基橙光化学降解反应一级动力学常数随草酸浓度的增大呈先升后降的趋势,最佳草酸初始浓度为1 mmol/L;溶液p H的变化也显著影响甲基橙的脱色。光化学反应过程中溶液pH和Fe^2＋的浓度的变化和草酸的初始浓度有关。

英文摘要：

The behavior of methyl orange（MO） heterogeneous photocatalytic degradation was investigated under 500 W UVA light irradiation with nanometer α-Fe_2O_3 and oxalic acid,which could set up a so-called photo-Fenton-like system. The effect of the initial oxalic acid concentration on the photodegradation of MO was investigated. The changes of pH value and Fe^2＋during the reaction were also detected. The results indicated that MO could be degraded efficiently in the present of oxalic acid in the system. The constants of MO photochemical degradation via pseudo first-order kinetics were found to increase first and then decrease with the concentration of oxalic acid increasing,and the optimum concentration was 1.0 mmol/L. MO decoloration was obviously affected by the change of pH of the solution. During the photodegradation process,the pH and Fe^2＋concentration depended on the initial oxalic acid concentration.