F doping and P vacancy engineered FeCoP nanosheets for efficient and stable seawater electrolysis at large current density

Abstract

Due to the shortage of global freshwater resources and sufficient seawater resources, electrolysis of seawater has become a research hotspot. However, the presence of chloride ions in seawater greatly hinders the development of seawater electrolysis, therefore, constructing catalyst with high catalytic activity and stability against chloride corrosion is essential for seawater electrolysis. In this work, we synthesize F doped FeP and CoP nanosheets with P vacancies (F-FeCoPv@IF) by rapidly molten salt and gas-phase phosphorization strategy, which displays bifunctional activity for HER and OER in alkaline seawater. And the assembled F-FeCoPv@IF needs 1.94 V and 1.62 V to drive 1000 mA cm−2 for overall seawater splitting in alkaline seawater and simulated industrial seawater. And the F-FeCoPv@IF has outstanding long-term durability for over 100 h and nearly 100% FE. DFT calculations reveal that F-doping and P vacancies can synergistically modulate the electronic structure of FeCoP, which enable F-FeCoPv@IF serve as excellent bifunctional electrocatalyst.