Then, HER measurements were done as described above. Ni-dep was produced on Ti mesh, previously cleaned in HCl, acetone, and deionized water. Ni deposition was done on Ti mesh with dimensions of 3×3 mm, from the deposition bath containing 0.2 mol dm -3 H 3 BO 3 , 0.5 mol dm -3 NH 4 Cl, and 0.125 mol dm -3 NiSO 4 . The deposition was done in a 2-electrode electrochemical cell, using Ni foam as a counter electrode, under potentiostatic conditions (2.4 V) for 90 s. Under these conditions, the typical deposition current is around 50 mA. Once the deposition was done, Ni-dep electrodes were thoroughly washed with deionized water and transferred to the electrochemical cell or Rh-exchange solution, the same one as described above.