Investigation on the Kinetics of Electroreduction Processes at Dark TiO2 and SrTiO3 Single Crystal Semiconductor Electrodes

Abstract

The cathodic dark current at n-type Nb-doped TiO2 and Ha-treated SrTiOs electrodes in Fe(CN)63-, Fe +3, or IrC162-aqueous solution was meastired as a function of applied voltage, concentration of oxidizing agent, and pH. Two distinct current regimes were observed, differing by their Tafel slopes and by their concentration dependence. The most marked feature of the results was the saturation of the current as a function of concentration in the high current-density region. The experimental data were interpreted on the basis of a model involving electron transfer through surface states. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-10 to IP VoI. I27, No. 2 ELECTROREDUCTION PROCESSES 325 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-10 to IP

Sensitization of Nanocrystalline Metal Oxides with a Phosphonate-Functionalized Perylene Diimide for Photoelectrochemical Water Oxidation with a CoOxCatalyst

“…Interestingly, at higher applied potentials, the sharp photocurrent spike disappears, while the steady-state photocurrent remains the same (see Figure S12, Figure below). Our current best hypothesis is that the current spikes are related to ‘monoenergitic’ SnO 2 surface states acting as recombination centers (see section S6a), as has previously been proposed for SnO 2 and TiO 2 films. − …”

Dynamic Tuning of a Thin Film Electrocatalyst by Tensile Strain

“…The higher Tafel slopes at low overpotentials are often observed for semiconductors, where charge transfer is mediated by surface states 45,46 . We also conduct electrochemical impedance spectroscopy (EIS) measurements in the frequency range 1 Hz to 100 kHz at different strain conditions.…”

Does a Photocatalytic Synergy in an Anatase–Rutile TiO2 Composite Thin‐Film Exist?

“…[32] However, the average FQY indicated that only approximately 2.5 % of electrons trapped at the surface of TiO 2 took part in photoreduction exchanges with Rz molecules, where it was assumed that the remaining electrons at the surface took part in detrimental recombinations with travelling holes. [38,39] The photocatalysis of anatase-rutile phase composites: There are a number of reports that indicate the intimate mixing of anatase and rutile TiO 2 composites causes a synergic enhancement in photocatalysis. [11][12][13][14][15] However, this effect has primarily been observed within powdered titania slurries or pastes.…”

“…who demonstrated that the photo‐generated electron and hole formation and surface trapping processes are on the femtosecond to picosecond time‐scale,37 far faster than the electron/hole transfer or recombination processes that follow (nanosecond to microsecond time‐scale2). This was further supported by the observation that charge transfers within anatase take place exclusively at the material surface38, 39 and that electrons can travel unhindered for several micrometers 32. However, the average FQY indicated that only approximately 2.5 % of electrons trapped at the surface of TiO 2 took part in photoreduction exchanges with Rz molecules, where it was assumed that the remaining electrons at the surface took part in detrimental recombinations with travelling holes 38.…”

“…However, the average FQY indicated that only approximately 2.5 % of electrons trapped at the surface of TiO 2 took part in photoreduction exchanges with Rz molecules, where it was assumed that the remaining electrons at the surface took part in detrimental recombinations with travelling holes 38. 39…”