活性炭纤维基Fe-N-TiO_2复合材料的制备及表征

Fabrication and characterization of Fe-N-codoped nano-TiO_2/activated carbon fiber composites

为解决纳米TiO_2在光催化处理纺织印染废水中可见光利用率低、粉体难回收的问题,采用溶胶-凝胶法制备Fe-N-TiO_2可见光催化剂;以黏胶基活性碳纤维(ACF)毡为负载基体,用浸渍负载法制备Fe-N-TiO_2负载活性炭纤维光催化复合材料(Fe-N-TiO_2/ACF).利用X射线衍射(XRD)、紫外-可见漫反射吸收光谱(UV-Vis DRS)、X-射线光电子能谱(XPS)和扫描电镜(SEM)表征Fe-N-TiO_2/ACF的晶相组织和纤维结构;以弱酸性红RN染液为目标降解物,测试材料的光催化性能.结果表明,在硝酸铁、尿素、钛酸丁酯的质量摩尔比为1.25∶400∶100,煅烧温度为400℃时,所制复合材料中Fe-N-TiO_2晶粒均为锐钛矿相,平均粒径17.1nm,且均匀分布在ACF表面,其吸收边带红移至528nm,禁带宽度减小到2.35eV.在300 W金卤灯照射下,光催化反应180min,0.12g Fe-N-TiO_2/ACF复合材料对100mL质量浓度为5mg/L弱酸性红RN染液的降解率达98.7%,远高于单一光催化剂的降解率.

In order to solve the problem that nano-TiO2 exhibits a low visible light utilization rate and is difficult to recycle in textile printing and dyeing wastewater treatment, Fe-N-TiO2 photocatalysts are prepared by sol-gel method, and then Fe-N-codoped nano-TiO2/activated carbon fiber（ACF）composites are fabricated by making Fe-N-codoped nano-TiO2loaded on the surface of ACF in impregnating method. The structure and morphology of the composites are characterized by X-ray diffraction（XRD）, UV-Visible diffusive reflectance spectroscopy（UV-Vis DRS）, X-ray photoelectron spectroscopy（XPS）, and Scanning electron microscope（SEM）. The photocatalytic performance of the composites was evaluated by using weak acid red RN solution as degradation target. Results show that Fe-N-TiO2 particles of composites are single anatase phase, and the average particle size is 17.1nm, when the molar ratio of nitric acid iron, urea and butyl titanate is 1.25：400：100, and the calcinated temperature is 400 ℃. Fe-N-TiO2 particles in the composites are homogeneously dispersed on the surface of ACF. The absorption band edge of Fe-N-TiO2 exhibits an evident red shift to 528 nm and forbidden band width is reduced to 2.35 eV. The degradation rate of weak acid red RN reaches to 98.7% when the dosing quantity of Fe-N-TiO2/ACF composite is 0.12 g/100 mL, irradiated under 300 W metal halide lamp for 180 min, which is much higher than that of Fe-N-TiO2photocatalyst.