| Several new wide band gap semiconductor nanocomposite photocatalytic materials have been synthesized from HTiNbO5 and HNb3O 8 for solar energy conversion. As a source of renewable energy, the materials are being tested to produce hydrogen fuel from water via photolysis. The materials have high surface areas, are macroporous, and have flatband potentials suitable for reducing water to create hydrogen. Under visible or ultra violet light, the materials were found to be very promising as hydrogen evolving photocatalysts. As part of the synthesis of the composites, the catalysts also exhibited excellent catalytic activity under UV light for reducing ionic platinum and gold out of solution and onto the surfaces of the catalysts. A topotactic dehydration treatment was also developed as a way to enhance the electronic conductivity within the solids and to improve catalytic activity. Topotactic dehydration increased the photocatalytic activity of the wide band gap semiconducting materials as much as 75% in some cases. Under visible light and when sensitized with N3 dye (cis-bis(isothio cyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)), these materials exhibited their great potential in producing hydrogen from water splitting under sunlight, with a maximum apparent quantum yield of 61.66%. |
