  The polymer of intrinsic microporosity PIM 1 is employed to disperse and
deposit a Pt at titanate nanosheet photocatalyst film. The resulting
microporous films allow electrolyte and oxygen permeation to give conventional
oxygen reduction voltammetric responses on glassy carbon or on platinum disk
electrodes in the dark. Preliminary data are presented showing that with pulsed
light from a blue LED oxygen reduction at the electrode is effectively switched
off. A mechanism is tentatively assigned as photocatalytic depletion of oxygen
near the electrode. Photoelectrochemical current responses are observed in
aqueous NaOH, NaCl, Na2HPO4 and shown to be light intensity and oxygen
concentration dependent. Electroanalytical applications are suggested.
