Solar energy surface modified electrodes

Solar energy, 6, 488 surface modified electrodes, 6, 30 Sol-Gel process fast reactor fuel, 6, 924 Solid state reactions, 1, 463-471 fraction of reaction, 1, 464 geometric, 1, 464 growth, 1, 464 nucleation, 1, 464 rate laws, 1,464 Solochrome black T metallochromic indicators, 1,555 Solubility... 

The deliberate modification of electrode surfaces by coating with one or more layers of electroactive material has been used for a variety of purposes. Solar energy conversion, electrochromism, corrosion protection, and electrocatalysis are but a few of the applications which are currently of interest. The use of in situ Raman spectroscopic studies can help to determine the structural characteristics of electrode coatings at the molecular level and can provide information on the mechanisms of electrochemical reactions occurring at modified electrode surfaces. 

Despite extensive studies, the photovoltage or the solar-to-chemical energy conversion efficiency still remains relatively low. The main reason is that it is very difficult to meet all requirements for high efficiency. For example, high catalytic activity and sufficient passivation at the electrode surface are incompatible. It was found, however, that a semiconductor electrode modified with small metal particles can meet all the requirements and thus becomes an ideal type semiconductor electrode. Cu, Ag, and Au were chosen because they were reported to work as efficient electrocatalysts for the C02 reduction. p-Si electrodes modified with these metals in C02-staurated aqueous electrolyte under illumination produce mainly methane and ethylene.178 This is similar to the metal electrodes but the metal-particle-coated electrodes work at approximately 0.5 V more positive potentials, contrary to continuous metal-coated p-Si electrodes. 

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