Importance of characterising the cocatalyst structure in the development of photocatalysts for the splitting of water

Abstract

In the development of new photocatalysts the surface of materials with some known catalytic activity is modified by the addition of cocatalysts such as partially oxidised nickel. The exact structure of these cocatalyst nanoparticles potentially has a large effect on the properties of the material as they are expected to act as electron traps and increase the catalyst activity. In the partially oxidised nickel system the cocatalyst structure is expected to consist of a metallic nickel core surrounded by a nickel oxide shell, however there is often little characterisation data to support this. In the present TEM study of the supposed NiO/Ni/InTaO4 system it was found that there was diffusion or migration of the indium possibly from the photocatalyst into the cocatalyst, which is suggested to be a nickel indium oxide surrounding a mixed nickel indium alloy nanoparticle. © 2010 IOP Publishing Ltd.