Comparison of charge transfer dynamics in polypyridyl ruthenium sensitizers for solar cells and water splitting systems

Abstract

Standard ruthenium components of dye-sensitized solar cells (sensitizer N719) and dye-sensitized photoelectrochemical cells (sensitizer RuP and water oxidation catalyst RuOEC) are investigated in the same solar cell configuration to compare their photodynamics and charge separation efficiency. The samples are studied on time scales from femtoseconds to seconds by means of transient absorption, time-resolved emission and electrochemical impedance measurements. RuP shows significantly slower electron injection into a mesoporous titania electrode and enhanced fast (sub-ns) electron recombination with respect to those of N719. Moreover, RuOEC is found to be responsible for partial light absorption and electron injection with low efficiency. The obtained results reveal new insights into the reasons for the lower charge separation efficiency in water splitting systems with respect to that in solar cells. The important role of the initial processes occurring at the dye-titania interface within the first nanoseconds in this efficiency is emphasized.

The Effect of Chloride Anions on Charge Transfer in Dye-Sensitized Photoanodes for Water Splitting

“…The representative absorption spectra of the photoanodes sensitized with RuP alone, RuOEC alone, and both dyes together (RuP + RuOEC) are shown in Figure 1. We determined the extinction coefficient for RuP in ethanol to be ≈14,250 M −1 cm −1 (455 nm), and that for RuOEC was ≈4300 M −1 cm −1 (530 nm), as previously reported [19]. The spectra recorded for dye layers on the TiO 2 (Supplementary Figure S2), suggests that ca.…”

Angstrom Thick ZnO Passivation Layer to Improve the Photoelectrochemical Water Splitting Performance of a TiO2 Nanowire Photoanode: The Role of Deposition Temperature

“…From optical perspective, elemental doping using metal and non-metal particles 12 – 24 , hydrogen treatment 25 – 30 , semiconductor sensitization 31 – 37 , dye sensitization 38 – 45 , and plasmonic metal incorporation 46 – 54 are examples of the ideas on the development of PEC performance of the TiO 2 . As discussed above, the ultimate goal of these studies is further improvement in light absorption toward longer wavelengths as visible (Vis) and near infrared (NIR) regimes.…”

Quinoline‐Coupled Coumarin‐Based Ruthenium(II) Dye Sensitizer for Photoelectrochemical Cells and Solar Cells: A Mimic for an Artificial‐Light‐Harvesting System

“…[4] Latterly, molecular hydrogen can be produced from the water-splitting process using dye-sensitized photoelectrochemical cells, in which a photosensitizer is attached to a mesoporous TiO 2 semiconductor that drives the half-cell reactions of conversion of water to O 2 and H 2 . [5][6][7][8][9] In this context, photoelectrochemical hydrogen production from photoactive cathodes based on dye-sensitized TiO 2 semiconductors is of great interest. TiO 2 -based photocathodes were acquired by loading of nanostructured TiO 2 films with dyes and seemed to enhance the photoelectrochemical activity in aqueous media.…”

“…NPs(5) where A 0 and A are the absorbance intensities of RQC in the absence and presence of diverse concentrations of TiO 2 nanoparticle suspension, respectively, A c is the absorbance of the ground-state RQC …. TiO 2 nanoparticle suspension complex, and [TiO 2 NPs] is the concentration of TiO 2 nanoparticle suspension.…”