V_2O_5改性TiO_2光催化剂制备及其对有机污染物光催化降解性能研究

Preparation and Photocatalytic Properties of TiO_2 Photocatalyst Based on V_2O_5 Modification

[目的]研究V2O5改性Ti O2光催化剂制备及其对有机污染物光催化降解性能。[方法]通过沉淀-浸渍法,利用Ti Cl4与NH4VO3制备了基于V2O5改性的Ti O2光催化剂。以亚甲基蓝为模型化合物考察了改性方法及制备条件对光催化性能的影响,并进行了UV、XRD分析,初步探讨了光催化降解动力学行为。[结果]V2O5-Ti O2催化活性大大高于Ti O2,且焙烧前改性效果明显高于焙烧后改性;V2O5-Ti O2最佳制备条件为p H=7、500℃焙烧4 h、V2O5含量为5.2%;V2O5改性一定程度上扩大了Ti O2光激发波长,提高了紫外光的吸收能力,但未改变Ti O2的晶体结构及光催化降解的一级反应动力学特征。[结论]V2O5-Ti O2对有机污染物光催化降解具有广阔的应用前景。

[Objective] The research aimed to study preparation and photocatalytic properties of TiO2 photocatalyst based on V2O5 modification.[Method]TiO2 photocatalyst based on V2O5 modification was prepared by the method of precipitation- impregnation with TiCl4 and NH4VO3.Photodegradation experiments of methylene blue aqueous solution were carried out to study the effects of preparation conditions,and the spectral character and crystal structure were analyzed by UV and XRD,and the kinetics characteristic of photodegradation was studied.[Result]The photocatalytic activity of V2O5-TiO2 is much higher than that of TiO2,and the photocatalytic activity of V2O5-TiO2 is better when TiO2 is modified before calcination. The optimized preparation conditions of V2O5-TiO2 are pH = 7,calacination at 500 ℃ for 4 h,5. 2% V2O5 in catalyst. The modification based on V2O5 extended the excitation wavelength range and the absorbility of TiO2,but this didn＇t change the crystal structure of TiO2 and the kinetics characteristics of photodegradation.[Conclusion]V2O5-TiO2 has broad application prospect in photodegradation of organic pollutant.