3D interconnected hollow network of Ni-Zn-Cu nanosheets with multifold nanotwins for enhanced hydrazine oxidation

• A Ni-Zn-Cu catalyst with 3D hollow-foam structure and multifold nanotwins is prepared. • The Ni-Zn-Cu catalyst exhibits excellent catalytic performance toward hydrazine electrooxidation. • 3D hollow-foam structure consisting of porous nanosheets is obtained using melamine foam. • Multifold nanotwin causes high strain and low coordination number, inducing a favorable d -band center. The hydrazine oxidation reaction (HzOR) is essential for direct hydrazine fuel cells and offers a promising alternative to the kinetically sluggish oxygen evolution reaction in water splitting. In this work, we present the design and synthesis of a novel Ni-Zn-Cu catalyst with a three-dimensional (3D) interconnected hollow network structure for HzOR. This unique 3D hollow architecture, comprising Ni-Zn-Cu nanosheets, significantly enhances HzOR catalytic performance by increasing the number of accessible active sites and improving both mass and charge transport. Additionally, the incorporation of multifold nanotwins within the catalyst induces lattice strain and reduces coordination numbers, optimizing the electronic structure and d -band center to strengthen hydrazine adsorption and catalyst reactivity. The Ni-Zn-Cu catalyst exhibits remarkable HzOR performance, achieving a current density of 200 mA·cm −2 , and a mass activity of 10,129 A·g −1 at −0.05 V vs. RHE, and a low onset potential of −0.15 V vs. RHE. Furthermore, it retains 96 % of its initial activity after 20 h of continuous electrolysis. This work marks a significant advancement in the development of highly efficient and durable HzOR catalyst.