Photoelectrocatalytic Cell Research Articles

A tungsten oxide-based photoelectrocatalyst for degradation of environmental contaminants

The use of photocatalysts in the remediation of contaminated water is now well established in the scientific literature, the most common photocatalyst being nano-dimensional particulate titanium dioxide. The generation of charge and charge transfer mechanisms on titanium dioxide are also well described, but this paper addresses the use of tungsten oxide and discusses its potential in water remediation when supported as a photoelectrocatalytic electrode. A photoelectrocatalytic cell is described and its performance in the context of the band structure of tungsten oxide is discussed.

Water electrolysis and photoelectrolysis on electrodes engineered using biological and bio-inspired molecular systems

Photoelectrocatalytic cells for water splitting should combine one or two photosensitive units with a water oxidation catalyst at the anode and a hydrogen evolution catalyst at the cathode. In this perspective article, we first show how a chemist can take the naturally occurring multi-electron catalysts for these two electro- and photochemical reactions, photosystem II and hydrogenases, as a source of inspiration for the design of original, efficient and robust molecular catalysts. The focus of this article is given to the immobilisation of these natural or bio-inspired catalysts onto conducting surfaces and the design of electrode and photoelectrode materials for hydrogen evolution/uptake and water oxidation.

Photoactive Silicon-Based Nanostructure by Self-Organized Electrochemical Processing

A solar cell design is presented that allows energy conversion in solid-state photovoltaics as well as in photoelectrochemical and photoelectrocatalytic cells. The energy-converting structure uses a Schottky-type, (i.e., metallic) nanoemitter, prepared by an oscillatory (photo)electrochemical process. Silicon shows (photo)current oscillations in fluoride-containing electrolytes that form an oxide with interspersed nanopores. Spatially selective electrodeposition of Schottky-barrier metals into these pores produces the nanoemitter contacts. The electrolyte structure shows pronounced photoactivity in a photoelectrochemical cell. Light-induced hydrogen evolution is obtained for structures made with . The energy-band alignments of the structures are discussed and routes for preparation of efficient solid-state devices are outlined.

Photoelectrochemical measurements of a heterosupramolecular system under visible light irradiation

A photochemical system utilising a modular approach characterised through interpretation of photoelectrochemical measurements is discussed. A photoanode was prepared by the chemisorption of a photosensitiser, cis-bis-(2,2'-bipyridine)-(4,4'-bis-(methyl)phosphonato-2,2'-bipyridine)ruthenium(II) dichloride (RuL2L'2+), to a mixed nanoporous nanocrystalline RuO2:TiO2 thin film, calcined on a fluorine doped SnO2 conducting glass substrate. Similarly, an electron relay molecule, 1-ethyl-1'-(2-phosphonoethyl)-4,4'-bipyridinium dichloride (EVP), was covalently bound to a platinum electroplated nanoporous nanocrystalline TiO2 thin film, and the electrodes connected in a photoelectrocatalytic cell (PCC). Irradiation with lamda > 420 nm gave a measurable photocurrent. Interpretation of the photocurrents obtained from this assembly provides a means for understanding photochemical reactions under low light intensities. Optimised conditions of the electrolyte solution were determined to be pH = 5 and illumination yielded eta = 0.0036% with an apparent quantum yield (AQY)= 1.6%.