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Ni-Mo nanocrystalline deposits (7–43 nm) with a nodular morphology were prepared by electrodeposition using direct current from citrate-ammonia solutions. They exhibited a single Ni-Mo solid solution phase. The size of the nodules increased as electroplating current density increased. The molybdenum content—estimated using EDX analysis—in the deposits decreased from about 31 to 11 wt% as the current density increased from 5 to 80 mA·cm−2. The highest microhardness value (285 Hv) corresponded to nanodeposits with 23% Mo. The highest corrosion resistance accompanied by relatively high hardness was detected for electrodeposits containing 15% Mo. Mo content values between 11 and 15% are recommended for obtaining better electrocatalytic activity for HER.

A two‐chamber galvanic cell enabled the simultaneous study of both oxidation and reduction processes involved in electroless copper deposition. The standing electrode potentials as well as the coupled electrode potentials were measured in the catholyte ( CuSO4 , normalNaOH , Rochelle salt) and in the anolyte ( HCHO , normalNaOH , Rochelle salt). The current passing during coupling was dependent on coupling time, catholyte and anolyte compositions, and the activation of the anode. The order of the deposition process as calculated from the coupling current compared favorably with that obtained by direct weight measurements. Evan's diagrams were constructed and used to correlate electrode potential, coupling current, and the mixed potential with the rate of the electroless deposition process.

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