Kinetic study of laser-induced photoelectrochemical processes at a dye solution semiconductor interface

Laser‐Induced Photoelectrochemical Transients at a Dye Solution/Semiconductor Interface: Presence of a Slow Photosensitized Process

“…The anchoring of rhodamine B to the SnO2 hydroxyl groups via an ester linkage, according to the method of Fujihira and Osa (14), has also been previously described (9).…”

“…The photopotential relaxes exponentially with time until a final value hVf, not till zero because one part of R + reacts and gives rise to an irreducible product P (reaction [4]). From hVf and the argument of the decreasing exponential, k3 and k4 have been determined (9), the inverse of their sum I/ks + k4 corresponding to the lifetime T(R +) of the adsorbed oxidized dye. With increasing hydroquinone (H2Q) concentrations, AVo remains constant, but AVf and the argument of the exponential decay increase *Electrochemical Society Active Member.…”

“…It was shown that the product k.~ 9 (1/k3 + k4) gives the Stern-Volmer constant Ksv = k.~(R+), which was also obtained independently under continuous illumination (12). Knowing the initial photopotential hV,, and the semiconductor capacitance, determined from impedance measurements, the initial injected charge hQo can be obtained and this was shown to be independent of the applied potential (9). Some observations, however, remained unclear (8).…”

Review of material properties of (Mo/W)Se2-layered compound semiconductors useful for photoelectrochemical solar cells

“…The voltage distribution at the n-WSe 2 and n-MoSe 2 /electrolyte interface is obtained from electroreflection and capacitance measurements (74). Photocell outputs of the order of 15 mA cm À2 and 0.5 V obtained in 100 mW cm À2 illumination show that the produced photo-voltage is not systematically dependent on the redox potential of the redox agent, but is influenced by the chemical reactivity due to a specific interaction with the electrode surface (75). Careful photo-etching of n-WSe 2 leads to a large improvement in its photo response.…”

Transient Photocurrents in WSe2 and MoSe2 Photoanodes

“…A similar technique was employed by Kamat and Fox (7) to study native and chemically modified TiO2 electrodes in acetonitrile solutions. Frippiat et al (8) studied the dye sensitization of SnOe with rhodamine B using a similar method.…”