Cu掺杂MIL-88B-Fe活化双氧水降解有机污染物性能研究

Performance study of Cu doped MIL-88B-Fe in activation of H_2O_2 for organic pollutants degradation

非均相类芬顿反应是一种去除水中难降解有机污染物的有效方法,但受限于Fe(Ⅲ)向Fe(Ⅱ)转换速率较慢,非均相类芬顿催化剂活性普遍偏低.通过溶剂热法制备了高活性Cu掺杂MIL-88B-Fe非均相类芬顿催化剂.以苯酚作为目标污染物,研究了Cu掺杂量对MIL-88B-Fe催化性能的影响.结果表明,掺杂Cu可以提高MIL-88B-Fe的催化性能,MIL-88B-Fe0.6Cu0.4的催化活性最高,其降解苯酚动力学常数是未掺杂MIL-88B-Fe的1.6倍,并且比一些常见的非均相类芬顿催化剂(Fe2O3、α-FeOOH及FeBiO3)高3个数量级.X射线光电子能谱(XPS)及电化学表征结果表明:Cu的掺杂可以加快催化剂中电子传递,促进催化剂中Fe(Ⅲ)/Fe(Ⅱ)氧化还原循环,从而提高MIL-88B-Fe催化效率.

Heterogeneous Fenton-like reaction is an effective method for degrading non-biodegradable organic pollutants in water. However, the activity of the heterogeneous Fenton-like catalysts is limited due to the low reduction rate of Fe(Ⅲ) to Fe(Ⅱ). Here, a highly effective heterogeneous Fenton-like catalyst Cu doped MIL-88B-Fe is prepared by solvothermal method. The effect of the doping amount of Cu on the catalytic performance of MIL-88B-Fe is studied choosing phenol as a target pollutant. It is found that doping Cu into MIL-88B-Fe can enhance the catalytic performance of MIL-88B-Fe. Among the doping catalysts, MIL-88B-Fe 0.6 Cu 0.4 exhibits the highest catalytic activity, its kinetic constant of phenol degradation is 1.6 times that of MIL-88B-Fe and is 3 orders of magnitude higher than those of other heterogeneous Fenton-like catalysts (Fe2O3,α-FeOOH and FeBiO3). The XPS and electrochemical characterization results show that doping Cu can enhance the electron transfer in catalyst, thus facilitate the redox cycle of Fe(Ⅲ)/Fe(Ⅱ). As a result, the catalytic efficiency of MIL-88B-Fe is improved.