Photochemical Generation of Catalytically Active Shape Selective Rhodium Nanocubes

A photochemical method has been exploited for the fast synthesis of shape selective rhodium (Rh) nanoparticles (NPs) in the presence of 2,7-dihydroxy naphthalene (2,7-DHN) as a new reducing agent under UV-photoirradiation for 6 h. The growth of particles with different shapes (spherical, flower like, and cubical) was directed by the surfactant-to-metal ion molar ratio and the concentration of 2,7-DHN. The particles' sizes and shapes were successfully tuned by varying the molar ratios of the reactants. The particles are stable for more than three months in ambient conditions. The synthesized CTAB-Rh NPs exhibit excellent catalytic activity toward the reduction of aromatic nitro Compounds by NaBH4 in an aqueous solution. The Rh NPs promoted the electron transfer between the BH4- and nitro compounds, which were reduced to their corresponding amino derivatives. The process presented here can be extended to the synthesis of other nanomaterials with desired sizes-and shapes and may find wide application in organic catalysis reactions, such as the reduction of different aromatic nitro compounds.