Mechanochemical synthesis of carbon-stabilized Cu/C, Co/C and Ni/C nanocomposites with prolonged resistance to oxidation

Abstract

Metal-carbon nanocomposites possess attractive physical-chemical properties compared to their macroscopic counterparts. They are important and unique nanosystems with applications including in the future development of nanomaterial enabled sensors, polymer fillers for electromagnetic radiation shields, and catalysts for various chemical reactions. However, synthesis of these nanocomposites typically employs toxic solvents and hazardous precursors, leading to environmental and health concerns. Together with the complexity of the synthetic processes involved, it is clear that a new synthesis route is required. Herein, Cu/C, Ni/C and Co/C nanocomposites were synthesized using a two-step method including mechanochemical treatment of polyethylene glycol and acetates of copper, nickel and cobalt, followed by pyrolysis of the mixtures in an argon flow at 700 °C. Morphological and structural analysis of the synthesized nanocomposites show their core-shell nature with average crystallite sizes of 50 (Cu/C), 18 (Co/C) and 20 nm (Ni/C) respectively. The carbon shell originates from disordered sp2 carbon (5.2–17.2 wt.%) with a low graphitization degree. The stability and prolonged resistance of composites to oxidation in air arise from the complete embedding of the metal core into the carbon shell together with the presence of surface oxide layer of metal nanoparticles. This approach demonstrates an environmentally friendly method of mechanochemistry for controllable synthesis of metal-carbon nanocomposites.

Synthesis of Air-Stable Cu Nanoparticles Using Laser Reduction in Liquid

“…Hence, we anticipate that the active bare Cu surfaces present immediately following laser irradiation catalyze the formation of the carbon shell. Although carbon shells are widely known to effectively protect transition metal NPs from oxidation [ 61 , 62 , 63 ], the evident permeability of the carbon around the LRL Cu NPs on the basis of their high catalytic activity suggests that a thin Cu 2 O layer around the Cu NPs also contributes to their observed stability [ 61 ].…”

Promotion of Photocatalytic Hydrogen Evolution under Visible Light with NiO/C Fabricated via a Super Facile and General Strategy

“…These values correspond to oxygen bonded with metal in the form of an oxide (NiO) and hydroxide (Ni(OH) 2 ), respectively. 43,44 The 45,46 Figure 5 presents the adsorption−desorption isotherms of the catalysts Ni@C-600-10, Ni@C-600-30, and Ni@C-600-60. The typical IV isotherms with H3 hysteresis loops are observed in the samples.…”

Solvent-Free Synthesis of MnOx-FeOx/Biochar for Hg0 and o-Xylene Removal from Flue Gas

“…During the mechanochemical process, high defect density and large amount of fractured chemical bonds generate in the biomass. ,, Metal species would combine with the matrix during the co-ball-milling of metal ions with biomass. The generated metal oxide particles are therefore incorporated and wrapped in the carbonaceous matrix during the pyrolysis carbonization and metal oxidation process.…”