自制掺Fe^(3+)锐钛矿型-TiO_2复合材料的光催化反应动力学研究

Photo-catalysis degradation kinetics of as-prepared Fe^(3+)-doping A-TiO_2 to acid Congo red

以自制的掺Fe^(3+)锐钛矿型TiO_2(A-TiO_2)为光催化剂,以酸性刚果红为降解对象,研究酸性刚果红的初始浓度C0、催化剂用量m和掺铁量χ等因素对自制A-TiO_2可见光催化降解反应动力学方程的影响和光催化剂对酸性刚果红的吸附性能。结果表明:在40W白炽灯照射下,当C0=20mg/L、m=0.6g/L(pH=6)、χ=1.2%(摩尔分数)、室温(18℃)下反应t=56min时,酸性刚果红的降解率最大D=92.7%。酸性刚果红的光催化降解过程符合一级反应动力学方程,于上述最佳条件下其表观反应速率常数k达到最大,为0.0404min-1。自制的光催化剂对C0分别为20、30和40mg/L的酸性刚果红吸附率E随C0增大而减小,110min达到吸附平衡,对20mg/L酸性刚果红的吸附率E达94.6%。D和E成正比。

Fe^（3＋）-doping anatase TiO_2（i.e.A-TiO_2）photo-catalyst was prepared via hydrothermal method.The main influence factors including the acid Congo red＇s initial concentration C0,TiO_2 dosage m,amountχof Fe^（3＋）-doping in A-TiO_2 were investigated for the kinetic equation of Fe^（3＋）-doping A-TiO_2 under visible light,and the adsorption property was also studied under dark condition.The results showed that the degradation rate D=92.7% of acid Congo red was the maximum under follow optimal conditions：acid Congo red＇s initial concentration C0=0 mg/L（pH=6）,catalyst dosage m=0.6 g/L,amount of Fe^（3＋）-dopingχ=1.2%（molar fraction）,and irradiated by 40 Wfilament lamp for t=56 min at room temperature（18℃）.The kinetic procedure of photo-catalytic degradation of acid Congo red was corresponded to the first-order kinetics equation,the degradation observed rate constant k（0.0404 min-1）achieved the maximum under the above optimum condition.The adsorption rate E of as-prepared photo-catalyst on acid Congo red was decreased with the increase of C0,when t=110 min,the adsorption equilibrium was reached,and for 20 mg/L acid Congo red solution,the adsorption rate E was 94.6%.D was proportional to E.