Wednesday, 1 June 2016: 11:00
Sapphire 410 A (Hilton San Diego Bayfront)
Extensive studies have been carried out on clean and renewable energy due to the pollution and depletion of fossil fuel. Ions doping is the efficient ways to enhance photocatalytic activity of titanium oxide (TiO2). Here we report photocatalytic activity of the Ni and Nb-doped TiO2 nanotube arrays photoanodes, respectively. The Ni-doped TiO2 nanotube arrays were fabricated through anodization of Ti50Ni alloys in electrolyte containing 5% ethylene glycol/glycerol containing (NH4)2SO4 and NH4F. Nb-doped TiO2 nanotube arrays were fabricated through anodization of Ti35Nb alloys in electrolytes of 1M NaH2PO4 containing 0.5 wt% HF. X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the doped TiO2 nanotubes photoanodes. The experimental results indicated that Nb and Ni doping could enhance the photocatalytic properties of the titanium oxide. The photocatalytic activity of Nb-doped TiO2 and Ni-doped TiO2 nanotube arrays photoanodes were 1.5 and 2 times as high as that of the undoped TiO2 nanotubes photoanodes, respectively. Density functional theory (DFT) calculations indicated that Ni-doping could narrow the band gap of undoped TiO2 through formation of impurity states and Nb doping could result in the valence band shift of the undoped TiO2. The doped TiO2 nanotube photoanode are promising for photoelectochemical water splitting application.