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以钛酸四丁酯为钛源,活性炭(AC)为载体,采用溶胶-凝胶法合成TiO2/AC复合体,利用TGA-DSC、SEM、XRD、DRS(漫反射光谱)及FTIR对复合体表面结构、光谱特征、晶体结构进行表征分析,并通过AAS(原子吸收分光光度计)测定铬(Ⅵ)、铜(Ⅱ)离子浓度以探讨超声-TiO2光催化还原去除率。研究表明:溶胶-凝胶法制备的TiO2/AC在290℃处由板钛矿型向锐钛矿型转变,500℃下焙烧催化活性最高;TiO2/AC复合体分散性能好、团聚尺寸低、比表面积大,其接触界面处有C—O—Ti键生成;经光催化动力学研究发现,光催化吸附还原机制符合一级动力学方程ln(c0/c)=kt及Langmuir-Hinshelwood吸附理论。对比无超声光催化,超声-光催化技术对铬(Ⅵ)、铜(Ⅱ)的还原去除率分别提高了39.32%和52.95%;催化剂循环使用3次后,超声-光催化还原铬(Ⅵ)、铜(Ⅱ)的去除率仍能达到70.61%和75.30%。
The TiO2 / AC composite was synthesized by sol-gel method using tetrabutyl titanate as titanium source and activated carbon (AC) as support. The structure of composite was characterized by TGA-DSC, SEM, XRD, DRS (diffuse reflectance) and FTIR The surface structure, spectral characteristics and crystal structure were characterized and characterized. The concentrations of Cr (Ⅵ) and Cu (Ⅱ) ions were determined by AAS to investigate the photocatalytic reduction efficiency of ultrasonic-TiO 2. The results show that TiO2 / AC prepared by sol-gel method changes from brookite to anatase at 290 ℃ and has the highest calcination activity at 500 ℃. The TiO2 / AC composite has good dispersibility, low agglomeration size, C-O-Ti bond was formed at the contact interface. The photocatalytic kinetics showed that the photocatalytic reduction mechanism was in accordance with first-order kinetic equation ln (c0 / c) = kt and Langmuir-Hinshelwood adsorption theory . Compared with non-ultrasonic photocatalysis and ultrasonic-photocatalysis, the reductive removal rates of chromium (Ⅵ) and copper (Ⅱ) increased by 39.32% and 52.95%, respectively. After the catalyst was recycled for three times, , Copper (Ⅱ) removal rate can still reach 70.61% and 75.30%.