Hierarchical P-doped TiO2 nanotubes array@Ti plate: Towards advanced CO2 photocatalytic reduction catalysts

• Published in: Ceramics international 2016-11, Vol.42 (14), p.16405-16411
• Main Authors: Wang, Keda, Yu, Jing, Liu, Lijun, Hou, Lin, Jin, Fengyou
• Format: Article
• Language: English
• Subjects: CO2; P-doped TiO2; Photocatalytic reduction; Solar energy materials
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2016.07.149

In order to narrow band gaps of semiconductor oxides and extend their working spectra scope, doping non-metal elements with oxides has been an effective strategy. While, doped non-metal elements also bring new charge-carrier trapping and recombination centers, which correspondingly result in the quantum efficiency losses caused by the charge pair recombination. Fortunately, it is demonstrated that the interface of oxide-metal has the abilities to effectively inhibit the recombination of the electron-hole pairs due to the fact that the charge pairs can be spatially separated and the electrons are transported to the surface active sites rapidly. Herein, as a proof-of-concept experiment, P-doped TiO2 nanotube array@Ti plate (P-TiO2 NT@Ti plate) hierarchical photocatalysts have been obtained via facile electrochemical anodic oxidation and pyrolytic phosphating approaches. Impressively, obtained P-TiO2 NT@Ti plate photocatalysts show reduced band gaps (3.02–3.16eV), high activities and excellent selectivity in the photocatalytic reduction of CO2 to CH3OH (the maximum CH3OH yield is 860.4μmolg−1cat. for 3.0h under visible-light irradiation) as a result of the improved electron-hole pair separation rate on the oxide-metal interface, as well as high light harvesting effects derived from the hierarchical nanotube structure.