摘要
基于密度泛函理论的第一性原理分别研究了不同浓度Br和I掺杂BiOCl体系的能带结构、态密度、形成能和光学性质.研究结果表明,由于Br的4p和I的5p轨道作用,Br和I掺杂可在一定程度上降低BiOCl的禁带宽度,拓宽BiOCl的光吸收范围.Br和I掺杂BiOCl的形成能计算结果表明,Br掺杂BiOCl的稳定性高于I掺杂体系.对于B,C,N,Si,P和S掺杂BiOCl体系,掺杂能级的形成主要由掺杂元素的np轨道贡献,使BiOCl吸收带边红移至可见光区.而S掺杂则位于价带顶位置,有效地降低了BiOCl禁带宽度,使BiOCl响应波长出现红移,且未形成中间能级,不易成为俘获陷阱,因此S掺杂将是一种提高BiOCl可见光光催化活性的改性方法.
The band structures, density of states, formation energies and optical properties of different con-centration Br and I doped BiOCl systems were investigated via first principles based on the density functional theory. The results show that the incorporation of Br 4p and I 5p orbitals can reduce the energy gap of BiOCl, and then broaden the photo-absorption range. The calculated formation energy indicates that Br-doped BiOCl system has higher stability than I-doped BiOCl at the same doping concentration. For B, C, N, Si, P, S doped BiOCl systems, the impurity energy levels are mainly contributed to the np states of doping elements, which can make the red-shift of photo-absorption band edge into visible light region. Especially, the impurity levels of S-doped BiOCl system located in the top of valence band are difficult to become recombination center of photon-generated carriers, which can result in the reduction of BiOCl band-gap and the red-shift of light-responding scope. The S-doped BiOCl system will be a preferable modification method to improve the photo-catalytic activity of BiOCl.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第12期2624-2631,共8页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21176168)
山西省(青年)自然科学基金(批准号:2014021019-3)
山西省高等学校科技创新项目资助~~
关键词
非金属掺杂
第一性原理
电子结构
光吸收性质
光催化
BiOCl
Non-metal doping
BiOCl
First-principle
Electronic structure
Optical absorption property
Photocatalysis
