Engineering FeP4/CoFe2O4 heterostructure with balanced proton adsorption ability for efficient hydrogen evolution reaction

• A novel heterostructure with abundant FeP 4 nanoparticles grown on the surface of CoFe 2 O 4 nanosheets is constructed for efficient HER catalysis. • FeP 4 not only promotes the proton adsorption process but also improves the electron structure around the Co sites for optimizing H* coupling and H 2 evolution process. • FeP 4 /CoFe 2 O 4 with larger active surface area and higher intrinsic activity demonstrates a much improved HER performance (η100 = 168 mV) and a faster reaction kinetics than the pristine FeP 4 and CoFe 2 O 4. Developing cost-efficient electrocatalysts for hydrogen evolution reaction (HER) with low overpotential, fast kinetics and good stability is one of the challenges to promote the industrial application of water electrolysis technology. Herein, we construct a novel heterostructure electrocatalyst with abundant FeP 4 nanoparticles grown on the surface of CoFe 2 O 4 nanosheets for efficient HER catalysis. FeP 4 , as the crucial co-catalyst, not only promotes the proton adsorption process due to its large electronegativity but also improves the electron structure around the Co sites for optimizing H* coupling and H 2 evolution process. Consequently, the FeP 4 /CoFe 2 O 4 heterostructure electrocatalyst shows a much improved HER performance (η 100 = 168 mV) and a faster reaction kinetics by comparing with the pristine FeP 4 and CoFe 2 O 4 . Further electrochemical characterization demonstrates that the heterostructure is also beneficial to increase active sites and enhance intrinsic activity. This work provides a feasible perspective for constructing heterostructure to acquire excellent HER catalysts.