Solvent-assisted morphology confinement of a nickel sulfide nanostructure and its application for non-enzymatic glucose sensor

Morphology-controlled synthesis of nickel sulfide (Ni₃S₂) was performed directly on Ni foam using thioacetamide as a sulfur ion source. Various morphologies of nickel sulfide were fabricated using a hydrothermal process by adjusting the solvent composition of ethanol and water. In the water-dominant condition, a dendrite structure was obtained; otherwise, a flaky structure was achieved. A hierarchical cauliflower-like structure was obtained at a solvent mixture composition of 1:1 and was used as non-enzymatic glucose sensor. The hierarchical Ni₃S₂ electrode showed a high level of electro-catalytic activity toward the oxidation of glucose (16,460 μA mM^-1 cm^-2) over a wide range of detection (0.0005-3 mM) and a low detection limit (0.82 μM) with excellent selectivity in the presence of several electroactive species.