碳量子点改性纳米二氧化钛的制备及其光催化降解壬基酚聚氧乙烯醚的性能研究

Preparation and photocatalytic activity of carbon-quantumdot-modified nano-TiO2

以柠檬酸为碳源,以1-氨丙基-3-甲基咪唑溴盐离子液体为表面修饰剂,一锅热解法制备了离子液体修饰碳量子点(L-CQDs),再通过简单的水热法将L-CQDs负载到TiO2纳米颗粒上。以表面活性剂壬基酚聚氧乙烯醚(TX-10)溶液为模拟废水,研究了L-CQDs/TiO2复合光催化剂的光催化性能。傅立叶变换红外光谱仪(FT-IR)和高分辨透射电子显微镜(HRTEM)表征结果证明L-CQDs负载到TiO2纳米颗粒的表面上;固体紫外-可见吸收光谱结果表明,L-GQDs/TiO2相比于TiO2纳米颗粒在可见光区域的吸收得到了明显增强;光催化结果表明,复合光催化剂3%L-CQDs/TiO2在500W氙灯照射下降解0.05g/LTX-10溶液3h时,复合光催化剂对TX-10的降解率最高可达83.5%,比TiO2纳米颗粒高26.6%;重复使用5次后复合光催化剂的光催化活性保持不变。

Ionic-liquid-modified carbon quantum dots(L-CQDs) were prepared by one-pot pyrolysis using citric acid as carbon source and 1-aminopropyl-3-methyl-imidazolium bromide as surface modifier. TiO2 nanoparticles were loaded with L-GQDs by one-step hydrothermal method. Using a solution of nonylphenol polyoxyethylene ether(TX-10) as the simulated wastewater, the photocatalytic performance of L-CQDs/TiO2 composite photocatalyst was studied. The characterization results are proved by FT-IR and high-resolution transmission electron microscopy(HRTEM) that L-CQDs are loaded onto the surface of TiO2 nanoparticles. The UV-visible absorption spectrum show that the absorption of L-GQDs/TiO2 in the visible region is significantly enhanced compared with TiO2 nanoparticles. The results of photocatalysis show that the degradation rate of 3% L-CQDs/TiO2 to 0.05 g/L TX-10 solution could reach 83.5% under illumination of Xenon lamp for 3 h, which is 26.6% higher than that of TiO2 nanoparticles. The photocatalytic activity of the composite photocatalyst remain unchanged after repeated use for 5 times.