Low-Temperature Liquid Phase Synthesis of Flower-like NiCo₂O₄for High-Efficiency Methanol Electro-oxidation

As a multifunctional spinel oxide, NiCo2O4 has been extensively applied in the field of electrochemistry. In this work, a simple liquid phase precipitation method was presented for the preparation of flower-like NiCo2O4 at a low temperature without any surfactant. The obtained flower-like NiCo2O4 with a large surface area of 110.4 m2 g-1 exhibits a much higher methanol electro-oxidation current of 148 mA cm-2 at 0.6 V (vs. Hg/HgO), compared to those of Co3O4 (19.1 mA cm-2) and NiO (47.6 mA cm-2) synthesized via the same procedure. After examination by chronoamperometry at 0.6 V for 1200 s, the NiCo2O4 retains a high current density of 103 mA cm-2. The high catalytic activity suggested the application prospect of the flower-like NiCo2O4 in the energy field and the advanced nature of the simple liquid phase precipitation method.