Hierarchical CuCo2O4/NiCo2O4 on self-standing Ni foam for high-performance water electrolysis

The development of overall alkaline water electrolysis process is the most promising to hydrogen production for future renewable energy resources. Nevertheless, the rational design and development of efficient noble metal free electrodes with robust stability is a great challenge to achieve efficient overall water splitting performance. Herein, we report a novel hierarchical CuCo ₂O ₄/NiCo ₂O ₄ (CCO/NCO) heterostructures grown on Ni foam via facile two-step hydrothermal method and calcination processes for overall water splitting activity. The prepared heterostructures electrode demonstrates the superior electrocatalytic activity with excellent durability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte condition. The as-prepared CCO/NCO/NF electrodes exhibits the electrocatalytic activity with exceptionally lower overpotential of less than 250 mV at 10 mA/cm ² (OER) and 72 mV at 10 mA/cm ² (HER). Remarkably, the alkaline electrolyzer has delivered an excellent overall water splitting with fine cell voltage 1.58 V (at 10 mA/cm ²) with stability test at 10 mA/cm ² for 20 h while, electrolyzer setup has constructed using self-standing heterostructures electrodes as both anode and cathode. The improved electrocatalytic performances of heterostructures electrode could be attributed to the significant interface between active hierarchical CCO/NCO/NF heterostructures which provide enhanced catalytic active sites on catalyst surface. Thus, the proposed hierarchical heterostructures electrocatalyst opens a new pathway to design the noble metal-free efficient bifunctional electrocatalyst for water splitting electrolysis under alkaline condition.