One-step formation of a hybrid material of graphene and porous Ni with highly active Ni(OH)₂ used for glucose detection

A hybrid material of graphene and porous Ni with highly active Ni(OH)₂ was formed through a one-step electrochemical exfoliation assisted method. The porous Ni with a pore size of 2–10 micrometers obtained by a hydrogen bubble template method was used as the cathode while the graphite foil was used as the anode with only (NH₄)₂SO₄ as the electrolyte. Both the high surface areas of porous Ni and the oxygen radicals in graphene favored the formation of the Ni(OH)₂. It is confirmed by energy dispersion spectrum, transmission electron microscope, Raman spectroscopy, x-ray diffraction and x-ray photoelectron spectroscopy analysis. Both the active area and the glucose sensing property of the as-prepared hybrid material were estimated by electrochemical methods of cyclic voltammetry with current-voltage (C-V) curve, chronoamperometry with current-time (I-t) curve and electrochemical impedance spectroscopy analysis, respectively. It shows an extraordinary active area as well as a low charge transfer resistance and absorption resistance. As a result, a high sensitivity of 6504 μA/mM⁻¹ cm⁻² within a linear range of 4 μM–1.0 mM was obtained for glucose detection. (paper)