The rotating optical disc–ring electrode. Part 1.—Collection of a stable photoproduct

Abstract

The rotating optical disc–ring electrode consists of a transparent disc surrounded by a concentric ring electrode. Light is shone through the central disc to drive a photoredox system. The current from the photogenerated product is measured downstream on the ring electrode. The convective diffusion equation for this system is solved and analytical solutions are presented for the collection of a stable product. The theory takes into account the bleaching of the solution. Experiments performed on the iron–thionine system are found to be in good agreement with the theory.