Redox reactivity, irradiated semiconductor surfaces

Controlled Organic Redox Reactivity on Irradiated Semiconductor Surfaces... 

In principle, the arrangement of reactive intermediates generated by electron - hole pair capture by two redox couples on the semiconductor surface may allow for divergent reaction paths when the same reactive intermediates are generated on the irradiated surface and in an isotropic environment. If a particular reactive intermediate is quite stable, the overall chemistry observed may be... 

The utility of visible- or UV-sensitive semiconductors as initiators for redox chemistry is limited by the instability of the surface under irradiation while in contact with an oxidizable substrate or an electrolyte. This decreased activity is caused by the chemical reactivity of the semiconductor itself, so that an insulating (blocking) layer is formed or the electrode quickly corrodes. This lack of stability is particularly troublesome with small-band-gap semiconductors that adsorb strongly in the visible region. 

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