Sol-hydrothermal Preparation of N-P-TiO2Nano-particles for Photocatalytic Degradation of 4-Chlorophenol under Sunlight Irradiation

Hongquan Jiang, Qiaofeng Wang, Jingshen Li, Qingyuan Wang, Zhenyu Li
2012 Huaxue xuebao  
哈尔滨师范大学功能材料设计合成与绿色催化黑龙江省高校重点实验室 哈尔滨 150025) 摘要 以尿素和磷酸为掺杂剂、 冰醋酸为抑制剂, 利用溶胶-水热技术制备了介孔锐钛矿型 N-P-TiO 2 片状纳米粒子; 以 4-氯酚溶液在模拟太阳光照射下的光催化降解评价其光活性; 结合 XRD, TEM, BET, XPS, DRS, PL 和 ζ-电位分析, 探讨 了 N 和 P 掺杂对 TiO 2 光活性的影响机制. 结果表明, 与未掺杂、N 或 P 单掺杂 TiO 2 相比, N-P 共掺杂 TiO 2 具有更高的 光催化降解 4-氯酚活性. N-P 共掺杂 TiO 2 的可见光响应是由 N 2p, P 3p 分别与 O 2p 轨道杂化导致带隙窄化引起的. N-P 共掺杂产生协同作用, 进一步改善 TiO 2 的表面织构特性, 增加表面羟基, 抑制光生 e -/h + 复合, 增强表面酸性提高其水 分散性, 导致 N-P 共掺杂 TiO 2 的光活性提高. Abstract Mesoporous N-P-codoped anatase-TiO 2 nano-sheets were
more » ... essfully synthesized by a sol-hydrothermal method which utilized urea and phosphorous acid as dopants, and glacial acetic acid as inhibiting agent. Their photoactivities were evaluated by the photocatalytic degradation of 4-chlorophenol (4-CP) in aqueous solution under simulated sunlight irradiation. In combination with XRD, TEM, BET, XPS, DRS, PL and zeta potential characterization, the effect mechanisms of N and P doping on the photoactivities of TiO 2 were discussed. The results revealed that the N-P-codoped TiO 2 exhibited higher photocatalytic activity for 4-CP degradation than the undoped, N-doped or P-doped TiO 2 . The visible light response of the N-P-codoped sample may be attributed to narrowing of the band gap resulted from hybridization by the 2p orbits of N atom, 3p orbits of P atom and the 2p orbits of O atom, respectively. The N-P-codoping can further improve the surface texture properties of TiO 2 , and increase the surface hydroxyl, and inhibit the recombination of photogenerated electrons and holes, and enhance the dispersive capacity in water due to the increase of the surface acidity, which imply that the N-P-codoping produces synergetic effects, therefore resulting in the enhanced photoactivity of N-P-codoped TiO 2 .
doi:10.6023/a12060341 fatcat:2bxgpecrujhcbiikfl6tfg6x3a