Low-crystallinity FeP nanosheets as efficient electrocatalyst for hydrogen evolution

Low-crystallinity and ultrathin iron phosphide nanosheets loading on carbon paper (FeP sheets/CP) were synthesized by hydrothermal and solid–gas phosphating method, acting as an efficient self-supporting electrode for hydrogen evolution reaction (HER). Compared with FeP cubes/CP and FeP rods/CP composites, FeP sheets/CP composites exhibit higher specific surface area due to its lamellar structure favoring the exposure of active sites. Meanwhile, the FeP sheet exhibits low crystallinity due to the addition of surfactant and low-boiling-point ethanol solvent. Electrochemical measurements showed that FeP sheets/CP composites showed great electrocatalytic activity against HER, with overpotentials of only 73 and 156 mV at current density of 10 mA cm⁻² in 0.5 M H₂SO₄ and 1.0 M KOH, respectively.