摘要
利用溶胶-水热法制备了未掺杂、N掺杂、Gd掺杂和Gd-N共掺杂TiO2纳米光催化剂,以甲基橙(MO)溶液在紫外光和可见光照射下的光催化脱色评价其光活性;采用XRD、XPS、BET、UV-Vis和PL分析技术表征样品的物理化学性能,探讨Gd-N共掺杂对TiO2光活性的影响机制。结果表明,Gd掺杂能有效抑制光生e-/h+的复合,提高光量子效率;抑制TiO2晶粒生长,改善样品表面织构特性,明显提高紫外光活性。N掺杂窄化TiO2带隙,拓宽光吸收范围至可见光区,从而提高了可见光活性。Gd-N共掺杂进一步窄化带隙增加可见光吸收,减小晶粒尺寸,改善样品的表面织构特性,增强织构的热稳定性。与单掺杂样品相比,Gd-N-TiO2在可见光照射下对MO的光催化脱色活性进一步提高,这归因于Gd-N共掺杂的协同效应。
Un-doped, N-doped, Gd-doped and Gd-N-codoped TiO2 nano-photocatalysts were successfully prepared by a sol-hydrothermal method. Their photocatalytic activities were evaluated by photocatalytic deeoloration of methyl orange dye in aqueous solution under UV and visible light irradiation, respectively. The physicoehemieal properties of as-prepared samples were characterized by XRD, XPS, BET, UV-Vis and PL analytic techniques. The effect of Gd-N-codoping on the photoactivity of TiO2 was also discussed. The results showed that Gd-doping could effectively inhibit the recombination of photogenerated electron-hole pairs, then enhancing photo quantum efficiency. Gd-doping could inhibit the growth of crystalline size and improve the surface textural properties. Therefore, the UV photoaetivity was obviously enhanced by Gd-doping. N-doping could make the absorption edge red-shift to visible light range by narrowing the electronic band structure, which enhanced the visible light photoactivity. Gd-N-codoping could further increase the absorption to visible light by narrowing the electronic band structure, and further decrease the crystalline size and improve the surface textural properties, therefore increasing the thermal stability. Compared to the single-doped TiO2, Gd-N-TiO2 significantly improved the photoactivity for decoloring methyl orange in aqueous solution under visible light irradiation, which was ascribed to the synergetic effect of Gd-N-eodoping.
出处
《应用化学》
CAS
CSCD
北大核心
2013年第5期560-566,共7页
Chinese Journal of Applied Chemistry
基金
黑龙江省高校科技创新团队建设计划(2011TD010)
哈尔滨师范大学青年学术骨干资助计划项目(08XBSK89)
