Improving the photoelectrochemical performance of nanostructured TiO2 films by adsorption of gold nanoparticles

TiO(2) films cast on conducting glass plates were modified by adsorbing gold nanoparticles (5 nm diameter) from a toluene solution. Selective formation of Au islands and larger particles on the TiO(2) surface could be seen from transmission electron micrographs and AFM images. Although the adsorbed Au particles are larger in diameter (50-70 nm), they retain surface plasmon characteristics, similar to those observed for smaller gold nanoparticles in solutions. A 3-fold enhancement in photocurrent generation has been achieved upon modification of TiO(2) films with Au nanoparticles. This improved photoelectrochemical performance is explained on the basis of improved interfacial charge-transfer kinetics of the TiO(2)/Au composite film. Such semiconductor-metal composite films have potential applications in improving the performance of photoelectrochemical solar cells.