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arXiv · 1210.7749

A DFT+U study of Rh, Nb codoped rutile TiO2

Kulbir Kaur Ghuman·Chandra Veer Singh
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Abstract

A systematic study of electronic structure and band gap states is conducted to analyze the mono doping and charge compensated codoping of rutile TiO2 with Rh and Nb, using the DFT+U approach. Doping of rutile TiO2 with Rh atom 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 mono-doping 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 Rh4+, thereby leading to a reduction in recombination centers and to the formation of more stable Rh3+. 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 TiO2 a more efficient and stable photocatalyst.

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Kulbir Kaur Ghuman, Chandra Veer Singh. 2012-10-29. A DFT+U study of Rh, Nb codoped rutile TiO2. https://doi.org/10.1088/0953-8984%2F25%2F8%2F085501

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