Facile preparation of water soluble CuPt nanorods with controlled aspect ratio and study on their catalytic properties in water

CuPt nanorods, originally nonpolar, were modified by ligand exchange to become soluble in water. Three different CuPt nanorods with aspect ratios (ARs) of 1, 6, and 11 were produced with high monodispersity by a thermal decomposition method and a subsequent purification process. The synthesized nanorods were initially dispersed in nonpolar solvents such as hexane. Thiol-terminated poly(ethyleneoxide) (PEO-SH) was synthesized and attached to the surface of CuPt nanorods to impart water solubility. The nanorods were completely transferred to the aqueous phase. Their catalytic properties in the aqueous phase were investigated using a peroxidase-like reaction of o-phenylenediamine (OPD) oxidation. CuPt nanorods showed high activity for the reaction, demonstrating the excellent dispersion of nanorods in an aqueous solution. The effect of AR on the catalytic properties of nanorods was also studied.