Hollow Urchin-Like FeP As Highly Efficient Hydrogen Evolution Catalyst

A novel self-supported hollow urchin-like iron phosphide (h-FeP) on carbon paper (h-FeP/CP) is synthesized by phosphating hollow Fe3O(OH) derived from selective etching treatment of FeAlOOH precursor. The as-obtained h-FeP/CP catalyst exhibits larger surface areas due to its specific hollow urchin-like structure, and thus endows more accessible active sites. The h-FeP/CP catalyst manifests the most prominent catalytic activity for hydrogen evolution reaction (HER). The current density of 10 mA cm-2 and 100 mA cm-2 are from the overpotentials of 90 mV and 258 mV in 0.5 mol/L H2SO4, respectively. And the current density of 10 mA cm-2 and 100 mA cm-2 are from the overpotential of 146 mV and 376 mV in 1.0 mol/L KOH, respectively. In addition, h-FeP/CP catalyst also exhibited excellent stability and durability at a large current density of 100 mA cm-2 in both acidic and alkaline solutions. The improved HER performance of h-FeP/CP is decided by the large amount of exposed activated sites and collective effects of large surface area, providing the faster interfacial charge transfer kinetic in the process of HER.