Controllable synthesis of flower-like Mn-Co-P nanosheets as bifunctional electrocatalysts for overall water splitting

Abstract Developing cost-effective and binder-free bifunctional electrocatalysts to boost the hydrogen and oxygen evolution reactions are crucial for overall water splitting. In this work, three-dimensional hierarchical Mn-Co-P/NF electrodes on nickel foam are synthesized by electrodeposition and chemical vapor deposition (CVD) firstly. Provide an excellent and controllable synthesis method by controlling the electrodeposition time and phosphating temperature. The Mn-Co-P composite exhibits the characteristics of vertically grown porous nanosheets, which can effectively expose the active sites. Benefit from the rational design with in-situ growth of functional materials and the unique structure, the Mn-Co-P/NF presents excellent electrocatalytic activities and stability with lower overpotentials of 63 mV and 310 mV to deliver 10 mA cm−2 for hydrogen evolution reaction (HER) and 10 mA cm−2 for oxygen evolution reaction (OER), respectively. Moreover, when directly used as a positive electrode and a negative electrode to form an electrocatalytic device to complete the overall water splitting, Mn-Co-P/NF merely requires a small cell voltage of 1.70 V to obtain 20 mA cm-2. This work offers a controllable method to design and synthesize highly efficient and stable transition metal phosphide catalysts for overall water splitting and other catalytic fields.