Charge transfer reductive doping of single crystal TiO2 anatase

Reduction Mechanism and Capacitive Properties of Highly Electrochemically Reduced TiO2 Nanotube Arrays

“…This new peak is well ascribed to the defect of Ti 3+ 2p 3/2 (oxygen vacancy, V o ) [17,32]. The Ti 3+ XPS peak was also observed in highly reduced titania such as vacuum-annealed TNAs [17] and lithium intercalated nanoporous anatase TiO 2 [32], but not in previously reported hydrogenised [13] and the references by using the similar approach [26,28] TNAs, where only $ 1% of the Ti 4 + in a TiO 2 layer were reduced to Ti 3+ or even there was no noticeable change in O 1 s core level XPS spectra. The content of the oxygen vacancies or Ti 3+ ions in the r-TNAs reported here is estimated to be about 22% of the total Ti ions by fitting the Ti 2p spectrum into four peaks of Ti 4+ (2p 1/2 , 2p 3/2 ) and Ti 3+ (2p 1/2 , 2p 3/2 ) and further calculating the signal intensity ratio of Ti 3+ : (Ti 4+ + Ti 3 + ).…”

“…31.7% of the total Ti 4+ ions were reduced as Ti 3+ states by the vacuum-annealing treatment [17], whereas only ca. 1% of the Ti 4+ in a TiO 2 layer could be reduced to Ti 3+ or even there is no noticeable change in O 1s core level XPS spectra using the electrochemical reduction approach [25][26][27][28]. The electrochemical reduction level was so low that the characteristic XPS peak of Ti 3+ 2p 3/2 could not be observed.…”

Prototype of a scalable core–shell Cu2O/TiO2 solar cell

“…In the doping process, the Ti 4+ ions in nanotube barrier layer can be reduced to Ti 3+ ions (Ti 4þ O 2 þ e À þ H þ ! Ti 3þ ðOÞðOHÞ) which leads to donor states accompanied by an increased conductivity [22][23][24][25]. Figure 2a represents the cyclic voltammetry (CV) curves of the prepared TiO 2 nanotubes film in 1 M NH 4 Cl aqueous solution at a scan rate of 100 mV/s.…”

Graphene-based cathodes for liquid-junction dye sensitized solar cells: Electrocatalytic and mass transport effects

“…The titania photoanode has been studied thoroughly, ranging from investigation of single crystals [15,38] to advanced organized nanostructures [9,39]. Usually, the nanocrystalline TiO 2 (anatase) is deposited on transparent oxides (TCO), such as FTO or indium-tin oxide (ITO) serving as current collectors.…”