Catalyst bifunctional redox, colloidal

Efficient Water Cleavage by Visible Light in Colloidal Solutions of Bifunctional Redox Catalysts... 

This problem has been overcome only recently throu the development of bifunctional redox catalysts (1 ). The latter are distinguished by the fact that Pt and RUO2 are loaded onto the same mineral carrier particle. Colloidal Ti02 was the first material to be used as a siipport. It fulfills four different functions in the water splitting system (Figure 8) 1) It serves as... 

Figure 8. Schematic illustration of the intervention of a colloidal TiOfbased bifunctional redox catalyst in the cleavage of water by visible light.

Fig. 8.1a, b. Schemes for the visible light-induced decomposition of water a colloidal redox catalysts are present as separated entities. b Bifunctional redox catalyst Ru02 and Pt are codeposited on the colloidal Ti02 carrier particle... 

Although photoelectrochemical systems are able to offer respectable conversion efficiencies, the refinement of other solution-based processes continues. Gratzel has reviewed photoredox processes, paying particular attention to the use of organized assemblies such as micelles and vesicles. He emphasizes the central role of efficient colloidal metal catalysts in these schemes and also describes the recent development of bifunctional redox catalysts that allow the combination of cycles for the generation of hydrogen and oxygen. 

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