Characterized Semiconductor Electrodes: II . Room Temperature Diffusion in a Single Crystal Rutile Electrode

Abstract

The capacitance, spectral response, and volt-ampere characteristics of lightly reduced TiO~ photoelectrochemieal electrodes are all significantly altered by immersion in concentrated acids or by operation at sufficiently negative voltages. These changes, which are reversible, are attributed to diffusion of protons along the c-axis channels of rutile. There is an apparent threshold voltage for appreciable accumulation af protons which are presumed to enter the crystal as H atoms.

Enhancement of Photoelectrochemical Hydrogen Production from Hematite Thin Films by the Introduction of Ti and Si

“…The Tidoped film has a substantially higher response than the Si-doped film at all wavelengths. The drop-off in the IPCE at short wavelengths has been observed previously for hematite (see Figure 1) and other materials such as TiO 2 54 . The IPCE measurements for the Ti doped film in Figure 2C were analyzed by fitting a simple Schottky barrier model which assumes a solid film.…”

Sol−Gel Synthesis, Electrochemical Characterization, and Stability Testing of Ti0.7W0.3O2 Nanoparticles for Catalyst Support Applications in Proton-Exchange Membrane Fuel Cells

“…Hence, doped TiO 2 has the possibility of being both electrically conducting and kinetically stable under fuel cell conditions, assuming that the doping does not radically alter the chemical stability of the host lattice. Some transition metal oxides have been studied as electrodes or supports in a variety of electrochemical systems. ,− …”

“…Some transition metal oxides have been studied as electrodes or supports in a variety of electrochemical systems. 12,[23][24][25][26][27] Rutile has a tetragonal structure and is a large-band-gap semiconductor (3.0-3.5 eV). 28,29 Since pure titania has very few charge carriers, resulting in low electronic conductivity, conductivity must be achieved either by aleovalent cation substitution or by introduction of oxygen vacancies.…”

An approach to the effect of hydrogen loading on the anodic behaviour of Ti in NaOH solutions

“…The lower value of the dielectric constant of the oxide formed on the hydrogenloaded metal is an indication of its higher conductivity. The conductivity induced by generation of hydrogen is attributed to the diffusion of hydrogen atoms into the crystal where they donate their electrons to the conduction band, leaving interstitial proton [18]. A large change in the dielectric constant was also illustrated previously due to the loading of the TiO 2 films with hydrogen [17,20].…”