In situ grown nanosheet NiZn alloy on Ni foam for high performance hydrazine electrooxidation

Highlights: • 3D nanosheet structured NiZn alloy was prepared via combing electrodeposition and electrochemical leaching. • NiZn catalyst exhibits high activity and stability towards hydrazine electrooxidation. • The mechanism reason for the excellent durability of NiZn catalyst was studied. • First principles calculations were employed to gain insight into the catalytic mechanism. -- Abstract: The electrocatalyst with cost effective and high performance towards hydrazine electrooxidation is critical to promote the practical application of direct hydrazine fuel cell (DHFC). Herein, an effective approach is developed to study the NiZn alloy as promising hydrazine electrocatalyst by the combined experimental and theoretical investigations. 3D nanosheet NiZn alloy with single α-NiZn phase was successfully synthesized on Ni foam (NF) substrate through the electrodepostion of NiZn alloy and followed electrochemical leaching. The NiZn catalyst exhibits the synergetic capabilities of impressively high activity with a superior current density of 370 mA cm⁻² at 0.3 V, excellent durability with a retention rate of 88.7% after 5000 s and almost 100% selectivity for the complete electrooxidation of hydrazine, which is at the top level among the reported electrocatalysts for hydrazine oxidation up to now. The reason for the excellent durability of NiZn catalyst was studied. Specially, first principles calculations were employed to shed light on the catalytic mechanism of high performance NiZn catalyst.