煅烧温度对纳米SnO_2光催化降解亚甲基蓝的影响  

Effect of Calcination Temperature of SnO_2 on Photocatalytic Degradation of Methylene Blue

作　　者：马瑞[1] 万霞[1] 铁绍龙[1] 

机构地区：[1]华南师范大学化学与环境学院,广州510006

出　　处：《华南师范大学学报（自然科学版）》2014年第2期61-66,共6页Journal of South China Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(11374109)

摘　　要：采用四氯化锡与氢氧化钠在92℃下直接沉淀法制备了纳米级SnO2,经不同温度处理得到性质不同的SnO2样品.研究了处理温度对SnO2性质和紫外光(254 nm)照射下降解亚甲基蓝(MB)效率的影响.结果显示:200℃处理样品的降解率最高,超过该温度后,随着处理温度的升高,SnO2的粒径逐渐增大,比表面依次减小,表面吸附的羟基或水的数量减少,则样品的降解率逐渐减小.SnO2降解MB的反应为拟一级反应,满足Langmuir-Hinshelwood模型,且在UV/SnO2降解体系中,羟自由基OH·为主要的活性体,它与MB反应导致其最终分解为CO2、H2O和无机酸根离子等无害物质.The nano-SnOz sample was synthesized by direct precipitation of tin tetrachloride（SnCl4）and sodium hydroxide（NaOH） at 92 0C temperature and a series of SnOz samples with different characters were obtained by calcined at different temperatures. The effects of calcination temperature on characters of SnOz and photodegrada- tion of methylene blue（MB） under UV-light（254 nm） irradiation have been investigated. The SnOz sample cal- tined at 200 0C showed the highest degradation rate of MB. When the calcination temperature is over 200 0C,with increasing calcination temperature the particle size of SnOz increases and the specific area of SnOz decreases,so the degradation rates of MB are decrease. The photocatalytic degradation kinetics was analyzed in detail,which was found fitting a pseudo-first-order kinetics and the Langmuir-Hinshelwood model. In UV/SnOz system the hydroxyl radicals OH·play a critical role in the degradation of MB,inducing the complete mineralization of MB to carbon dioxide,water and mineral acid.

关 键 词：直接沉淀合成 纳米SNO2 亚甲基蓝 光催化降解 

分 类 号：O614.81[理学—无机化学]