摘要
在微波助离子液体介质中制备稀土元素Y掺杂改性TiO_2光催化剂,以提高催化剂的光催化降解活性,用XRD、SEM和BET等测试手段对催化剂结构进行表征;以甲基橙溶液和苯酚溶液为模拟污染物,分别在紫外光照(UV)和微波辐射-紫外光照(MW-UV)条件下考察TiO_2-Y催化剂的光催化活性;以对苯二甲酸作为荧光探针利用荧光技术检测TiO_2-Y催化剂表面所产生的羟基自由基,并对光催化降解反应进行动力学分析,探索了光催化降解反应机理.实验结果表明,通过优化反应条件后制得的TiO_2-Y催化剂具有较高光催化活性和热稳定性,在UV和UV-MW条件下降解甲基橙和苯酚溶液1.5h后,甲基橙降解率分别为98.3%和99.5%,苯酚降解率分别为97.5%和98.2%.荧光光谱分析表明,TiO_2-Y在MW-UV条件下产生的羟基自由基比UV条件下要多,因而微波辐照具有强化TiO_2-Y降解模拟污染物的作用;反应动力学数据分析表明,TiO_2-Y光催化降解甲基橙溶液反应呈现一级反应动力学规律,其表观速率常数K最大值为0.051 9min-1.
Y-doped TiO2 photo-catalysts were synthesized by a microwave aided sol-gel method using ionic liquid as a reaction medium.The purpose of the experiment was improvement for the photo-catalytic activity and accelerate the degradation of pollutants.The structure and morphology of Y-doped TiO2 were characterized using XRD,BET and SEM.The photo-catalytic activity was respectively investigated by ultraviolet irradiation（UV）and microwave irradiation with ultraviolet irradiation（MW-UV）using the photo-catalytic degradation of methyl orange and phenol solution as simulated pollutants.With terephthalic acid as the fluorescence probing,the influence of hydroxyl radical on the surface of TiO2-Y on the photo-catalytic activity was investigated by the fluorescence technology.To understand the reaction mechanism,the photocatalytic degradation kinetics was determined.The results showed that the TiO2-Y catalysts prepared at the optimum condition had higher photo-catalytic activity and heat stability,the degradation rate of methyl orange and phenol solution reaching 98.3% and 99.5%,97.5% and98.2%,respectively,under UV and MW-UV for 1.5h.The fluorescence spectra also indicated that the UV combining with MW technology could effectively improve the catalytic efficiency of TiO2-Y catalyst,for the amount of hydroxyl radicals under MW-UV irradiation were more than that under UV.The reaction kinetics data indicated the first order model for the photocatalytic degradation reaction of methyl orange,and that the maximum apparent rate constant K was 0.051 9min^-1.
出处
《化学研究》
CAS
2016年第2期234-240,共7页
Chemical Research
基金
国家自然科学基金资助项目(20663007)
关键词
离子液体
钇掺杂
TIO2光催化剂
微波强化
光催化活性
ionic liquid
Y-doped
TiO2 photo-catalysts
microwave enhancing effect
photocatalytic activity
