Preparation by Ball Milling–Thermal Decomposition Method and Characterization of Reduced Graphene Oxide Decorated with Ni Nanoparticles

Nickel acetate tetrahydrate [Ni(CH 3 COO) 2 ·4H 2 O] was used as a precursor to prepare reduced graphene oxide decorated with Ni nanoparticles (Ni-rGO) by a ball milling–thermal decomposition method. Ni-rGO was characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction analysis, Fourier-transform infrared spectroscopy, and Raman spectrometry, and the adsorption energy between Ni atom and rGO was calculated based on first-principles calculations using density functional theory. The results showed that ball milling could be used to effectively restrain the agglomeration and reduce the size of rGO, and improve the adsorption energy between Ni particles and rGO. With increase of the milling time, the nucleation sites of Ni particles increased while the size of the Ni nanoparticles decreased. The thermal decomposition products of Ni(CH 3 COO) 2 ·4H 2 O in Ar atmosphere were Ni with a very small amount of carbides. Ni-rGO was obtained by reduction of GO, ball milling, and thermal decomposition processes, and the combination between Ni atom and rGO was via chemisorption.