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 a sacrificial reagent has been investigated by using a simple home-made UV-LED light strip 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. The normalised activity/surface area of the studied Rh nanoparticles showed a trend that led to establishing a relationship between the exposed  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.