Taking Advantage of Potential Coincidence Region: Advanced Self-Activated/Propelled Hydrazine-Assisted Alkaline Seawater Electrolysis and Zn-Hydrazine Battery

Hydrazine-assisted water electrolysispresents a promisingenergyconversion technology for highly efficient hydrogen production. Owingto the potential coincidence region between hydrogen evolution reaction(HER) and hydrazine electro-oxidation, hydrazine oxidation reaction(HzOR) exhibits specific advantages on strategy combination, deviceconstruction, and application expansion. Herein, we report a bifunctionalelectrocatalyst of porous Ni foam-supported interfacial heterogeneousNi(2)P/Co2P microspheres (denoted NiCoP/NF), whichtakes full advantage of this potential coincidence region. Thanksto the 3D microsphere structure and strong interfacial coupling effectsbetween Ni2P and Co2P, NiCoP/NF demonstratesexcellent bifunctional electrocatalytic performance, requiring ultralowoverpotentials of 70 and 230 mV at 10 mA cm(-2) forHER and HzOR, respectively. When using NiCoP/NF as both electrodes,HzOR-assisted water electrolysis exhibits considerably decreased potentialscompared with the electro-oxidation of other chemical substrates.Furthermore, the potential coincidence region of 0.1 V makes the applicationof self-activated/propelled hydrazine-assisted alkaline seawater electrolysis,hydrazine-containing wastewater treatment, and Zn-hydrazine(Zn-Hz) battery realistic. The concept of potential coincidence regionprovided in this work has significant implications for water electrolysisand other related applications.

Automated summary

This study presents a bifunctional electrocatalyst of porous Ni foam-supported interfacial heterogeneous Ni(2)P/Co2P microspheres, which demonstrates excellent bifunctional electrocatalytic performance. The concept of potential coincidence region proposed in this work has significant implications for water electrolysis and other related applications.