Department of Materials Science and Engineering, University of Toronto, 184 College Street, Suite 140, Toronto, ON M5S 3E4, Canada.
J Phys Condens Matter. 2013 Feb 27;25(8):085501. doi: 10.1088/0953-8984/25/8/085501. Epub 2013 Jan 23.
A systematic study of electronic structure and band gap states is conducted to analyze the monodoping and charge compensated codoping of rutile TiO(2) with Rh and Nb, using the DFT + U approach. Doping of rutile TiO(2) with Rh atoms induces hybridized O 2p and Rh 4d band gap states leading to a red shift of the optical absorption edge, consistent with previous experimental studies. Since Rh monodoping may induce recombination centers, charge compensated codoping with Rh and Nb is also explored. This codoping induces an electron transfer from Nb induced states to Rh 4d states, which suppresses the formation of Rh(4+), thereby leading to a reduction in recombination centers and to the formation of more stable Rh(3+). A combination of band gap reduction by 0.5 eV and the elimination of band gap states that account for recombination centers makes (Rh, Nb)-codoped TiO(2) a more efficient and stable photocatalyst.
采用 DFT+U 方法对金红石 TiO(2)的单掺杂和电荷补偿共掺杂进行电子结构和带隙态的系统研究，Rh 和 Nb。Rh 原子掺杂金红石 TiO(2)会诱导 O 2p 和 Rh 4d 带隙态杂化，导致光吸收边缘红移，与先前的实验研究一致。由于 Rh 单掺杂可能会产生复合中心，因此还探索了 Rh 和 Nb 的电荷补偿共掺杂。这种共掺杂会引起电子从 Nb 诱导的态转移到 Rh 4d 态，从而抑制 Rh(4+)的形成，从而减少复合中心的形成，并形成更稳定的 Rh(3+)。带隙减小 0.5eV 和消除与复合中心相关的带隙态的组合使(Rh, Nb)共掺杂 TiO(2)成为一种更有效和稳定的光催化剂。
