Co-doped porous Ni5P4 nanoflower: An efficient hydrogen evolution electrocatalyst with high activity and electrochemical stability

We report a novel Co-doped porous Ni5P4 nanoflower as an efficient hydrogen evolution electrocatalyst with high activity and electrochemical stability. In 0.5 M H2SO4, Co-doped (6.6at.%) Ni5P4 has an overpotential of 310 mV at the current density of 10 mA cm−2, while Ni5P4 and Co-doped (3.3 at.%) Ni5P4 have the overpotential of 410 and 370 mV, respectively. In addition, the current density lost value of Co-doped (6.6 at.%) Ni5P4 after 18 h of reaction is negligible, and therefore has good stability. Co-doped (6.6 at.%) Ni5P4 exhibits excellent hydrogen evolution activity, which can be attributed to a stable surface and a highly conductive structure.