Rhodium nanoparticles impregnated on TiO2: Strong morphological effects on hydrogen production

The effect of the shape of rhodium nanoparticles impregnated on TiO2 on photocatalytic hydrogen generation using methanol as sacrificial reagent has been investigated by using a simple home-made UV-LED light strips reactor to activate the catalyst surface. For rhodium nanocubes, the normalised rate of H2 production was 22.4 mmol h-1 m-2 at 365 nm and 7.5 mmol h-1 m-2 at 400 nm. Normalised activity/surface area of the studied Rh nanoparticles showed a trend that led to establishing a relationship between the exposed [100] facets and photocatalytic activity. The Rh shape-dependent H2 production follows a trend of cubic > spherical > octahedral, which is associated with a higher surface energy of the Rh nanoparticles.