碳纳米管负载二氧化钛的制备及其对甲基橙的光催化降解

Preparation of carbon nanotubes supported titanium dioxide and its photocatalytic degradation for methyl orange

采用溶胶-凝胶法,以钛酸四丁酯为前驱体,羧基化多壁碳纳米管(oCNTs)为载体,乙醇为溶剂,冰醋酸为抑制剂,成功制备了TiO_2纳米粒子负载碳纳米管的复合光催化剂(TiO_2/o CNTs).通过XRD、TEM、UV等测试手段对复合材料进行了表征.结果表明:经450℃煅烧3 h后制备的TiO_2/o CNTs复合体系中,纳米TiO_2呈现锐钛矿且均匀包覆在碳纳米管表面.o CNTs的存在能够有效改变复合材料的表面性质,以实现TiO_2对紫外光的敏感性.当TiO_2和o CNTs的质量比为1∶0.03、TiO_2/3%o CNTs催化剂使用量为0.8 g/L时,对20 mg/L甲基橙溶液紫外灯照射1 h,甲基橙溶液的降解率达到99%,而同等条件下纯TiO_2对甲基橙的降解率不到50%,说明o CNTs能够有效提高TiO_2对甲基橙的光催化活性.TiO_2/3%o CNTs光催化剂对甲基橙进行5次循环降解,降解率保持在95%左右.

By using sol-gel method with tetrabutyl titanate as precursor, carboxylic multi walled carbon nanotubes （oCNTs） as carrier, ethanol as solvent, acetic acid as inhibitor, the composite photocatalyst of TiO2 nanoparticles sup-ported on carbon nanotubes （TiO2 /oCNTs） was synthesized successfully. The prepared TiO2 /oCNTs nanocomposite materials were characterized through X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and UV-vis spectra （UV-vis） etc. The results showed that in the TiOs/oCNTs composite prepared by calcination at 450 t for 3 hours, Nano TiO2 was anatase and even coated on the surface of oCNTs. The existence of oCNTs can effectively change the surface properties of the composite in order to realize the sensitivity of TiO2 to UV light. When the TiO2 and oCNTs were dispersed in the solution with the mass ratios of 1 ： 0.03, and the amount of the TiO2/oCNTs catalyst was 0.8 g/L, the methyl orange solution was 20 mg/L, which was lighted under UV radiation for 1 h, the degradation rate of the methyl orange in the photocatalystr s experimental was about 99%. At the same conditions, the degradation rate of pure TiO2 for methyl orange was below 50%. This indicated that the oCNTs can improve the photocatalytic activity of TiO2 towards methyl orange. Methyl orange was cyclic degra- dated with five times by the TiO2/3% oCNTs photocatalyst when the mass ratios of TiO2 and oCNTs is 1 ： 0.03, its degradation rate remained at 95%,catalyst recovery reached 95%.