Engineering the Band Gap States of the Rutile TiO2(110) Surface by Modulating the Active Heteroatom

• Published in: Angewandte Chemie International Edition Vol. 57; no. 28; pp. 8550 - 8554
• Main Authors: Yu, Yaoguang, Yang, Xu, Zhao, Yanling, Zhang, Xiangbin, An, Liang, Huang, Miaoyan, Chen, Gang, Zhang, Ruiqin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 09-07-2018
• Edition: International ed. in English
• Subjects: Band gap; band gap states; Catalysis; Chemical reduction; CrVI reduction; density functional theory; Photocatalysis; rutile TiO2; Solar energy; substitutional N doping; Titanium dioxide
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201803928

Introducing band gap states to TiO2 photocatalysts is an efficient strategy for expanding the range of accessible energy available in the solar spectrum. However, few approaches are able to introduce band gap states and improve photocatalytic performance simultaneously. Introducing band gap states by creating surface disorder can incapacitate reactivity where unambiguous adsorption sites are a prerequisite. An alternative method for introduction of band gap states is demonstrated in which selected heteroatoms are implanted at preferred surface sites. Theoretical prediction and experimental verification reveal that the implanted heteroatoms not only introduce band gap states without creating surface disorder, but also function as active sites for the CrVI reduction reaction. This promising approach may be applicable to the surfaces of other solar harvesting materials where engineered band gap states could be used to tune photophysical and ‐catalytic properties.
Band gap state engineering: Band gap states are introduced to the surface electronic structure of rutile TiO2 by substituting the in‐plane oxygen atoms of the (110) facet with nitrogen atoms without creating surface disorder. The modified material is able to reduce CrVI, which suggests that adsorption and heteroatom sites create an active surface that promotes charge transfer.