Synthesis and study of zirconium viologen-phosphonate compounds on a polymer surfactant template and their use in photocatalytic production of hydrogen

This paper describes a novel system, in which colloidal platinum particles and a zirconium viologen-phosphonate material (ZrVP) are both strongly interacting with a polymer surfactant template. A method of sequential treatment and dialysis was developed to grow the metal phosphonate compound on the phosphonate groups of the polymer surfactant template. This polymer surfactant also functions as a protecting agent for platinum colloids in aqueous solution to prevent aggregation and precipitation. Monitoring the growth of ZrVP by electronic spectroscopy shows that the compound grows incrementally on the polymer surfactant template. Transmission electron microscopic study shows a blanket-like morphological feature for these templated materials. Photoreduction of viologen in these compounds leads to the formation of a stable charge separated state. Photoreduced materials are very air-sensitive. Photochemical hydrogen generation shows a 5 times higher yield of H-2 than an analogous microcrystalline sample without a polymer surfactant template. (C) 1997 Elsevier Science Ltd. All rights reserved.