One-pot electrodeposition synthesis of NiFe-phosphate/phosphide hybrid nanosheet arrays for efficient water splitting

Developing facile and cost-effective synthetic strategies for efficient overall water splitting (OWS) catalysts is critical to renewable energy industry. Herein, the one-pot electrodeposition synthesis of hybrid NiFe-phosphate/phosphide (NiFe-Pi/P) nanosheet arrays on Ni foam (NF) as bifunctional catalytic electrode is freshly proposed. Through electrodeposition process, nano morphology and bimetallic synergism of NiFe-Pi\P can be well controlled, resulting in hybrid micro crystallization, nanosheet array structure, superhydrophilicity and superareophobicity characteristics, all of which guarantee high activity, rich active sites and quick mass transfer process on electrode surface. The fabricated electrode exhibits excellent activity on hydrogen evolution reaction (HER), the optimum one displays overpotential of 97 mV and 185 mV to acquire current responses to 20 mA cm−2 and 100 mA cm−2 respectively, which are close to those of Pt/C catalyst in alkaline medium. Besides, the electrode shows good activity for oxygen evolution reaction (OER) to deliver 20 mA cm−2 at 255 mV as well. More importantly, in long-term multi-step current electrolysis over 27 h, the symmetrically assembled cell adopting NiFe-Pi/[email protected] electrode needs only 1.57 V to get 10 mA cm−2, and negligible voltage elevation is revealed with current density cyclic variations. This work provides practical insights into synthesis of hybrid nanosheet array OWS catalysts in efficient approach and on a large scale.