新型聚2-氨基苯磺酸改性TiO_2纳米颗粒的制备及光催化性能

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·OHh+·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。

Synthesis and photocatalytic property of new poly-2-aminobenzene sulfonic acid modified TiO2 nano particles

In order to improve the photocatalytic activity of TiO₂, the poly-2-aminobenzene sulfonic acid modified TiO₂ (P2ABSA/TiO₂) nano particles were synthesized via the in situ oxidative polymerization method. The prepared nano particles were characterized by TEM, EDS, XRD, UV-Vis DRS and Photocurrent Test. The methylene blue was used as simulated pollutants, the synthesis conditions of nano materials were optimized, the influences of initial pH value and P2ABSA/TiO₂ concentration on photocatalytic effect were investigated, the contributions of reactive oxidation species were determined by using trap experiment in photocatalytic process. The results show that the optimum synthesis conditions of P2ABSA/TiO₂ nano particles are P2ABSA, TiO₂ and oxidant amount of substance ratio 2:1:2, HCl concentration 1.2 mol/L. There is a P2ABSA film on the surface of TiO₂. The modification of P2ABSA does not impact on the phase and grain size of TiO₂. P2ABSA/TiO₂ nano particles enhance the response to visible light and photocurrent density (from 18.3 μA/cm² to 28.7 μA/cm²). The photocatalytic degradation rate of methylene blue increases from 92.0% to 99.0%, with initial pH value increasing from 3.93 to 11.36, the optimum concentration of P2ABSA/TiO₂ nano particles is 1.5 g/L. The contribution order of reactive oxidation species in photocatalytic process is ·OH > h⁺ > ·O₂^-, the photosensitization effect of P2ABSA to TiO₂ is a key reason for enhancing photocatalytic activity of P2ABSA/TiO₂ nano particles.