文献类型：期刊文献

英文题名：Density functional theory study of mixed-phase TiO2: heterostructures and electronic properties

作者：Li, Wei-Kun[1,2,3,4];Hu, Peijun[1,2,3,4,5];Lu, Guanzhong[1,2];Gong, Xue-Qing[1,2,3,4]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China;[3]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[4]E China Univ Sci & Technol, Ctr Computat Chem, Shanghai 200237, Peoples R China;[5]Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT9 5AG, Antrim, North Ireland

年份：2014

卷号：20

期号：4

外文期刊名：JOURNAL OF MOLECULAR MODELING

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000334934900003)】；

基金：The authors thank the financial support from National Basic Research Program (2010CB732300, 2011CB808505), National Natural Science Foundation of China (21322307), Shanghai Rising-Star Program (12QH1400700), and Fundamental Research Funds for the Central Universities. P. H. thanks the Chinese Government for the program of "Thousands Talents". Computing time in the National Super Computing Center in Jinan is acknowledged.

语种：英文

外文关键词：Mixed-phase materials; Photocatalysis; Photogenerated electrons/holes; Titanium dioxide

摘要：In this work, density functional theory calculations have been performed to study the geometric, electronic, and energetic properties of two-phase TiO2 composites built by joining two single-phase TiO2 slabs, aiming at verifying possible improvement of the photo-activities of the composites through phase separation of excitons. We find that such desired electronic properties can be determined by several factors. When both the HOMO and LUMO levels of one of the two single-phase TiO2 slabs are higher than the corresponding ones of the other, the composite may have native electronic structures with phase-separated HOMO-LUMO states, especially when the two slabs exhibit highly matched surface lattices. For those pairs of TiO2 slabs with the HOMO and LUMO levels of one phase being within the range of those of the other, though the energetically favored composite give HOMO-LUMO states within one phase, one may still be able to separate them and move the HOMO state to the interface region by destabilizing the interactions between the two slabs.