Mechanism of reduction of rutile with hydrogen

One-Dimensional Titanium Dioxide Nanomaterials: Nanotubes

“…Other reasoning for enhanced photocatalytic properties of reduced TiO 2 particles was that it had an altered Fermi level leading to an increased height of the Schottky barrier that repels electrons from the particle surface 469 . Electrical conductivity 474 and Fourier transform infrared spectroscopy 475 suggested OV and Ti 3+ to be present in the modified TiO 2 . The presence of hydroxyl groups in the treated TiO 2 was confirmed by infrared spectroscopy by the appearance of OH absorption peaks, indicating that the hydrogen is bound to O atoms of the lattice, 470 however from those investigations it seemed not entirely clear if OH groups or Ti 3+ /OV formation are the main reasons for the improved photoactivity of TiO 2 after a H 2 treatment.…”

Autocatalytic Reduction of Hematite with Hydrogen under Conditions of Surface Control: A Vacancy-Based Mechanism

“…tions (36)(37)(38). During this initial stage of the reduction process, the reaction is confined to the surface of the pellet.…”

The enhancement of TiO2 photocatalytic activity by hydrogen thermal treatment

“…The H 2 treatment was a usual method to improve the surface and photoelectrochemical properties of TiO 2 (Chen et al, 1983;Howe and Gr€ a atzel, 1987;Qin et al, 1993;Rekoske and Barteau, 1997). More recently, some researchers have investigated the reduction mechanism in the temperature range of 300-500°C (Khader et al, 1993) and the surface stoichiometry (Haerudin et al, 1998) of the TiO 2 with H 2 treatment by means of Chemosphere 50 (2003) [39][40][41][42][43][44][45][46] www.elsevier.com/locate/chemosphere electrical conductivity (Khader et al, 1993) or Fourier transform infrared (FTIR) spectroscopy (Haerudin et al, 1998). Based on the results reported in the above literature, it seems that oxygen vacancies (OV) and trivalent titanium (Ti 3þ ) may be present in the modified TiO 2 .…”