Facile Synthesis of Ultrathin Nickel–Cobalt Phosphate 2D Nanosheets with Enhanced Electrocatalytic Activity for Glucose Oxidation

Two-dimensional (2D) ultrathin nickel–cobalt phosphate nanosheets were synthesized using a simple one-step hydrothermal method. The morphology and structure of nanomaterials synthesized under different Ni/Co ratios were investigated by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Moreover, the influence of nanomaterials’ structure on the electrochemical performance for glucose oxidation was investigated. It is found that the thinnest nickel–cobalt phosphate nanosheets synthesized with a Ni/Co ratio of 2:5 showed the best electrocatalytic activity for glucose oxidation. Also, the ultrathin nickel–cobalt phosphate nanosheet was used as an electrode material to construct a nonenzymatic electrochemical glucose sensor. The sensor showed a wide linear range (2–4470 μM) and a low detection limit (0.4 μM) with a high sensitivity of 302.99 μA·mM –1 ·cm –2 . Furthermore, the application of the as-prepared sensor in detection of glucose in human serum was successfully demonstrated. These superior performances prove that ultrathin 2D nickel–cobalt phosphate nanosheets are promising materials in the field of electrochemical sensing.