PHOTOCATALYTIC SPLITTING OF WATER - INCREASE IN CONVERSION AND ENERGY-STORAGE EFFICIENCY

The yield of the photocatalytic splitting of water using yl)-2-phenyl- 1,2-ethylenodithiolenic-S,S']tungsten as a photocatalyst-catalyst incr eases by more than threefold on going from 20 to 70-degrees-C, and the re is no indication that the effect levels off at this temperature. Th e intensity of light (within the error limits of our experiments) does not have an appreciable effect. The nature of the reversible electron acceptor also influences the energy storage efficiency, eg. 1,1-diben zyl-4,4'-bipyridiniumdichloride gives an energy storage efficiency app roximately 10% higher than methylviologen. The energy storage efficien cy also depends on the presence of electron donors; if PhN is added, t he energy storage efficiency increases by 20%. With ethylenediaminetet raacetic acid (EDTA) the results are even more spectacular; there is a twofold increase, but only initially. At longer times the system is u nstable. Overall light energy storage efficiencies can be as high as 7 %, and the expectations for further improvement are very good.