One-step in situ synthesis of NHₓ-adsorbed rhodium nanocrystals at liquid–liquid interfaces for possible electrocatalytic applications

Nearly monodisperse rhodium nanoparticles with adsorbed NHₓ were synthesized at the CCl₄–water interface. The presence of NHₓ-adsorbed species was confirmed by energy-dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS) studies. The synthesis of controlled size 2–38nm rhodium particles was studied as a function of reducing agent concentration by transmission electron microscopy (TEM). HRTEM confirmed the formation of rhodium nanoparticles having fringe spacing consistent with reported Rh (111) planes. The continuity of these films over an area of 1×1μm was revealed by atomic force microscopy (AFM) studies. The electrocatalytic application of these nanostructure Rh-NHₓ thin films for formaldehyde oxidation in 0.5M NaOH was investigated by cyclic voltammetry. The Rh nanoparticles formed by the present strategy are expected to be useful for other catalytic applications also.