Honeycomb-like Ni@C composite nanostructures: synthesis, properties and applications in the detection of glucose and the removal of heavy-metal ions

Abstract
Honeycomb-like Ni@C composite nanostructures have been successfully prepared via a simple two-step solution route. Homogeneous Ni nanospheres with an average diameter of ∼100 nm were first obtained via a DMF–water mixed solvothermal route; then honeycomb-like Ni@C composite nanostructures were prepared through the hydrothermal carbonization of glucose solutions with suitable amounts of Ni nanospheres. The as-obtained products were characterized by XRD, SEM, TEM, ED, EDS and Raman spectroscopy. It was found that the as-obtained honeycomb-like Ni@C composite nanostructures showed good electrochemical properties and could be used as an electrochemical sensor for the detection of glucose molecules. Furthermore, the honeycomb-like Ni@C composite nanostructures presented good capacities for selective adsorption of Pb2+ , Cd2+ and Cu2+ ions in water, and could be easily separated from water and reused.