Surface nanocrystal hydrogen-bonded complex for photochemical water splitting

Photocatalytic splitting of water in the heterogeneous system consisting of photosensitizer, intermediate electron carrier and catalyst for hydrogen evolution was studied. Molecules and nanocrystals of Mg phthalocyanine were used as photosensitizer; p-benzoquinone served as intermediate electron carrier, and finely dispersed platinum as catalyst for hydrogen evolution. With finely dispersed platinum in the system, the quantum efficiency by the hydrogen formation in the presence of molecules and nanocrystals of the MgPc sensitizer increased by an order of magnitude. It was found that the new adsorption centers are formed on the platinum-modified surface of silicon dioxide (SiO2). Adsorption of sensitizing molecules of Mg phthalocyanine on them increases the lifetime of the excited states of the latter. The luminescence characteristics of the adsorbates of Mg phthalocyanine nanocrystals on SiO2 were studied.