State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Nankai University, Tianjin 300071, PR China.
J Hazard Mater. 2011 Aug 30;192(2):538-44. doi: 10.1016/j.jhazmat.2011.05.048. Epub 2011 May 23.
In this article, a facile solvothermal method was introduced to synthesize mesoporous BiOBr microspheres with Bi(NO(3))(3) as Bi source. The synthesized catalysts were characterized by XRD, SEM, TEM, XPS, UV-vis, TG-DTA, and N(2)-adsorption-desorption, and their photoactivity was evaluated by gaseous toluene both under UV and UV-vis irradiation with Degussa TiO(2) P(25) as reference. The prepared BiOBr catalysts were of pure tetragonal phase and its band gap energy was calculated to be about 2.64eV. Comparing with P(25), BiOBr showed promoted photocatalytic activity under UV-vis irradiation, during which more than 90% of toluene was eliminated after 5h irradiation. Kinetic analysis further demonstrated the enhanced activity of BiOBr under UV-vis irradiation and the reaction rate constant k of BiOBr was nearly 2 times higher than that of P(25). The superior activity of BiOBr under UV-vis irradiation can be attributed to its hierarchical structure and suitable band gap energy. Moreover, the reacted intermediates under different light source were identified by GC-MS. Fifteen main intermediates were identified and a tentative pathway of toluene degradation by BiOBr was proposed.
本文采用简便的溶剂热法，以 Bi(NO(3))(3)为铋源合成了具有介孔结构的 BiOBr 微球。采用 XRD、SEM、TEM、XPS、UV-vis、TG-DTA 和 N(2)-吸附-脱附等手段对合成的催化剂进行了表征，并以 Degussa TiO(2) P(25)为参比，考察了其在紫外光和紫外-可见光照下对气态甲苯的光催化活性。所制备的 BiOBr 催化剂为纯四方相，其带隙能约为 2.64eV。与 P(25)相比，BiOBr 在紫外-可见光照下表现出更高的光催化活性，在 5h 的照射后，超过 90%的甲苯被消除。动力学分析进一步证明了 BiOBr 在紫外-可见光照下的增强活性，BiOBr 的反应速率常数 k 比 P(25)高近 2 倍。BiOBr 在紫外-可见光照下的优异活性可归因于其分级结构和适宜的带隙能。此外，还通过 GC-MS 鉴定了不同光源下的反应中间体。鉴定出 15 种主要中间体，并提出了 BiOBr 降解甲苯的初步途径。
