Facile deposition of gold nanoparticles on C₆₀ microcrystals with unique shapes

Gold nanoparticles were densely deposited on the surface of C₆₀ microcrystals having a variety of unique shapes. C₆₀ microcrystals were prepared by a conventional liquid–liquid reprecipitation method. The shapes of C₆₀ microcrystals, such as bipyramid, belt, disc, and rod, were achieved by carefully adjusting the solvent species in the liquid–liquid reprecipitation process. Gold nanoparticles were directly deposited on C₆₀ microcrystals without adding any conventional reducing agent but only heating HAuCl₄ in C₆₀ microcrystals ethanol dispersion containing CS₂. Scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, absorption spectroscopy, and X-ray photoelectron spectroscopy studies were conducted to characterize the gold–C₆₀ heterostructure. The gold–C₆₀ heterostructure showed charge transfer behaviour where gold was an electron donor and C₆₀ was an electron acceptor. C₆₀ microcrystals-supported gold nanoparticles also showed catalytic activity in reduction of p-nitrophenol at room temperature. A facile reduction mechanism was suggested for gold deposition on the surface of C₆₀ microcrystals.