论文部分内容阅读
为提高TiO_2的光催化活性,利用原位氧化聚合法制备聚2-氨基苯磺酸改性TiO_2(P2ABSA/TiO_2)纳米颗粒,通过TEM、EDS、XRD、UV-Vis DRS和Photocurrent Test进行表征,以亚甲基蓝为模拟污染物,优化纳米材料制备条件,考察初始pH值和P2ABSA/TiO_2浓度对光催化效果的影响,通过捕捉实验判定活性氧物种在光催化过程中的贡献。结果表明:P2ABSA/TiO_2纳米颗粒最优制备条件为P2ABSA、TiO_2和氧化剂的物质的量之比2∶1∶2、HCl浓度1.2mol/L;TiO_2表面存在一层P2ABSA膜,P2ABSA改性没有改变TiO_2的物相和晶粒尺寸;P2ABSA/TiO_2纳米颗粒对可见光的响应提高,光电流密度从18.3μA/cm2提高到28.7μA/cm2;溶液初始pH值由3.93升至11.36,亚甲基蓝脱色率由92.0%提高到99.0%,P2ABSA/TiO_2纳米颗粒浓度最佳值为1.5g/L;活性氧物种在光催化过程中的贡献大小顺序为·OH>h+>·O-2,P2ABSA对TiO_2的光敏化作用是P2ABSA/TiO_2纳米颗粒光催化活性得到提高的主要原因。
In order to improve the photocatalytic activity of TiO_2, poly (2-aminobenzene sulfonic acid) modified TiO_2 (P2ABSA / TiO_2) nanoparticles were prepared by in-situ oxidation polymerization and characterized by TEM, EDS, XRD, UV-Vis DRS and Photocurrent Test. Using methylene blue as a simulated pollutant, the preparation conditions of nanomaterials were optimized. The effects of initial pH value and P2ABSA / TiO 2 concentration on photocatalytic activity were investigated. The contribution of reactive oxygen species to photocatalytic activity was evaluated by capture experiments. The results showed that P2ABSA / TiO_2 nanoparticles had the best preparation conditions: the molar ratio of P2ABSA to TiO_2 and oxidant was 2:1:1 and the concentration of HCl was 1.2mol / L; the presence of a layer of P2ABSA membrane on the surface of TiO_2 did not change the modification of P2ABSA TiO 2 phase and grain size. The response of P2ABSA / TiO 2 nanoparticles to visible light increased, and the photocurrent density increased from 18.3μA / cm 2 to 28.7μA / cm 2. The initial pH of the solution increased from 3.93 to 11.36 and the decolorization rate of methylene blue decreased from 92.0 %, The optimal concentration of P2ABSA / TiO 2 nanoparticles was 1.5 g / L; the order of contribution of reactive oxygen species to photocatalytic process was · OH> h +> · O-2 and the sensitization of TiO 2 by P2ABSA The main reason for the increase of photocatalytic activity of P2ABSA / TiO 2 nanoparticles was observed.