Constructing multicomponent Ni(OH) ₂ based nanosheet arrays as high-efficiency electrocatalysts for oxygen evolution

Ni-based catalysts are among the most promising candidates for oxygen evolution reaction (OER) in water electrolysis. However, their catalytic activity and long-term stability under high current densities still require further improvement. The development of multiphase, polycrystalline Ni-based catalysts is expected to leverage synergistic interactions among different elements to enhance electrocatalytic water-splitting performance. Herein, we report the hydrothermal synthesis of self-supported multiphase Ni(OH) 2 -based nanosheet arrays, which facilitate efficient electron transport and expose abundant active sites. The resulting electrode delivers a low overpotential of 298 mV at a current density of 100 mA cm -2 and maintains stable OER performance for over 25 hours. This work provides a feasible strategy for designing and developing multiphase electrocatalysts for high current density applications.