La掺杂在BiOBr光催化剂氧化和还原性能调控中的不同作用（英文）

Distinct Role of La Doping in Regulating the Photo-Oxidation and Reduction of BiOBr Nanosheet

同时使用有机溴源十六烷基三甲基溴化铵(CTAB)和无机溴源NaBr,通过溶剂热法合成了具有层状类囊体结构的La掺杂BiOBr光催化剂。通过第一性原理(DFT)计算了La掺杂对BiOBr能带结构的影响。采用X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱及荧光光谱对催化剂进行了表征。在可见光照射下,以光催化降解酸性橙Ⅱ和氨氮废水测试了LaBiOBr的氧化性能;以亚甲基蓝为还原指示剂,测试了La-BiOBr的还原性能。研究表明,La的掺杂可以促进晶粒的堆积。而且BiOBr的氧化性能和还原性能分别被促进和抑制,即La的掺杂促进了BiOBr光催化剂的氧化性能,抑制了其还原性能。

Both organic cetyltrimethyl ammonium bromide(CTAB)and inorganic NaBr are served as the bromine source,the thylakoid-like La doped BiOBr photocatalysts were synthesized via a hydrothermal process.The obtained samples were first characterized by X-ray diffraction(XRD),N2 physical adsorption,scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV-visible spectroscopy,X-ray photoelectron spectroscopy(XPS)and photoluminescence(PL)spectroscopy.Then,the effects of photo-oxidation and reduction properties of BiOBr with La doping were investigated by DFT calculation.The photo-oxidation and reduction activity of the pure and La doped BiOBr samples were evaluated by photo-catalytic degradation of acid orangeⅡ,ammonia nitrogen and methylene blue reduction under visible light irradiation.The results showed that it could inhibit growth of BiOBr crystals and promote the stacking crystals when La doped.More importantly,the oxidation performances of BiOBr were promoted,where the reduction performances were inhibited in large part by La doping.