結(jié)構(gòu)和性能的影響
(南京師范大學 化學與環(huán)境科學學院，南京 210097)
摘 要: 分別以KI和KIO3為碘源，用改進的溶膠−凝膠法合成不同價態(tài)碘修飾的TiO2納米材料。采用XRD、UV-Vis、SEM、EDS、TG-DTA和BET等手段對催化劑進行表征，比較不同價態(tài)碘修飾和煅燒溫度對光催化劑結(jié)構(gòu)和性能的影響。結(jié)果表明：KI和KIO3修飾的TiO2均為銳鈦礦相，平均粒徑約為10 nm。由于在催化劑表面形成I2，KI和KIO3修飾增強TiO2在可見光區(qū)的吸收能力。煅燒溫度對KI修飾的催化劑影響較大，KI修飾可提高催化劑的比表面積和孔容，KIO3修飾改變TiO2的孔結(jié)構(gòu)，增大孔徑。在相同條件下，KI修飾的催化劑的比表面積是原催化劑的3.5倍(50.37 m2/g變?yōu)?76.74 m2/g)。KI和KIO3修飾的TiO2在模擬太陽光和紫外光下對亞甲藍的光活性均高于純TiO2的。
關(guān)鍵字: 改性TiO2；光催化劑；光催化；溶膠−凝膠法；KI；KIO3
activity of I-TiO2 photocatalysts synthesized by sol-gel method
（School of Chemistry and Environmental Science, Nanjing Normal University, Nanjing 210097, China）
Abstract:The different valence iodine modified TiO2 nanomaterials were prepared by the improved sol-gel method using KI or KIO3 as the iodine sources. The modified TiO2 photocatalysts were characterized by XRD, UV-Vis, SEM, EDS, TG-DTA and BET. The effects of different valence iodine and calcinated temperature on the structure and properties of catalysts were investigated. The results show that the photocatalysts modified by KI or KIO3 contain 100% anatase crystalline phase of TiO2, and the average particle size of that are about 10 nm. Because I2 is formed on the catalyst surface, KI and KIO3 modification increase the absorption of TiO2 in the visible region. The calcination temperature has great effect on the modified KI catalyst. KI modification can increase the catalyst surface area and pore volume, and KIO3 modification changes the structure of TiO2 and increases the pore diameter of TiO2. Under the same conditions, the surface area of catalyst modified by KI (176.74 m2/g) is 3.5 times than that of pure TiO2 (50.37 m2/g). The photoactivity of TiO2 modified by KI and KIO3 on the methylene blue is greater than that of pure TiO2 under simulated solar light and UV light.
Key words: modified TiO2; photocatalyst; photocatalysis; sol-gel method; KI; KIO3
