Controlled Electrodeposition Synthesis of Co-Ni-P Film as a Flexible and Inexpensive Electrode for Efficient Overall Water Splitting

Synthesis of highly efficient and robust catalysts with earth-abundant resources for overall water splitting is essential for large-scale energy conversion processes. Herein, a series of highly active and inexpensive Co-Ni-P films were fabricated by a one-step constant current density electro-deposition method. These films were demonstrated to be efficient bifunctional catalysts for both H-2 and O-2 evolution reactions (HER and OER), while deposition time was deemed to be the crucial factor governing electrochemical performance. At the optimal deposition time, the obtained Co-Ni-P-2 catalyst performed remarkably for both HER and OER in alkaline media. In particular, it requires -103 mV over potential for HER and 340 mV for OER to achieve the current density of 10 mA cm(-2), with corresponding Tafel slopes of 33 and 67 mV dec(-1). Moreover, it outperforms the Pt/C//RuO2 catalyst and only needs 160 mV (430 mV) overpotential for HER (OER) to achieve 200 mA cm(-2) current density. Co Ni-P electrodes were also conducted for the proof-of-concept exercise, which were proved to be flexible, stable, and efficient, further opening a new avenue for rapid synthesis of efficient, flexible catalysts for renewable energy resources.