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-TiO2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TiO2光活性的影响机制。 结果表明, 与未掺杂、N或P单掺杂TiO2相比, N-P共掺杂TiO2具有更高的光催化降解4-氯酚活性。 N-P共掺杂TiO2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TiO2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TiO2的光活性提高。%Mesoporous N-P-codoped anatase-TiO2 nano-sheets were successfully 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 TiO2 were discussed. The results revealed that the N-P-codoped TiO2 exhibited higher photocatalytic activity for 4-CP degradation than the undoped, N-doped or P-doped TiO2. 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 TiO2, 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 TiO2.
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