Fig. 5: Electrochemical HER performance of the nanoporous Mo-based intermetallic compounds and the reference materials tested as powder samples cast on a disk electrode.

a iR-corrected HER polarization curves. b Tafel plots. c Comparisons of overpotential at 10 mA cm−2geo current density and Tafel slopes. d EIS spectra collected at 200 mV overpotential. The insets are the zoom-in spectra and the electronic circuit for EIS fitting. e, f iR-corrected HER polarization curves with current normalized by the geometric surface area and the electrochemical active surface area (ECSA), respectively, for np-Co7Mo6 fabricated by LMD at the temperatures of 873 K, 973 K, and 1073 K. The catalyst loading is 2 mg cm−2 for all samples except for pure carbon.