FeCoP sub-nanometric-sheets for electrocatalzing overall water splitting

Renewable electrical energy for electrolysis water can achieve green industrial chains for hydrogen production. However, finding efficient electrocatalysts remains a challenge for green hydrogen. Herein, sub-nanometric FeCoP nanosheets with average thickness of 0.9 nm is constructed through 2D self-assembly driven by cavitation effect of ultrasonics and following phosphating. Benefiting from abundant active sites, enhanced H₂O molecular adsorption kinetics, and highly enhanced structural stability, the subcrystalline FeCoP shows excellent electrocatalytic activities of hydrogen evolution reaction (HER) and oxygen evolution reactions (OER). Ultralow overpotential of 37 mV is achieved at 10 mA·cm⁻² for HER. When the FeCoP catalyst was used as both cathode and anode for overall water splitting using renewable electrical energy, green hydrogen produced is directly applied for hydrogen fuel cell to drive fan for more than 10 h. Theoretical calculation indicates that subcrystalline FeCoP more easily adsorbs H₂O than crystalline one and thus speeds up the kinetics of Volmer step in HER process.