The Rh-exchanged Ni electrodes, starting with smooth Ni surfaces to nickel foam and Ni electrodeposits, were investigated by cyclic voltammetry for different duration of Ni immersion in rhodium salt solutions. In addition, the effects of electrode oxidation pretreatment were investigated to discuss the HER mechanism on modified electrodes. Apart from electrochemical measurements, the effects of the Rh-exchange process on the surface properties of Ni electrodes were also characterized by scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDX) and X-ray photoelectron spectroscopy (XPS). Moreover, Density Functional Theory (DFT) calculations were used to rationalize the enhancement of HER activity upon surface modifications with Rh. We note that this work is focused on the origins of HER activity enhancement on various Ni surfaces upon spontaneous displacement with Rh, while the stability of investigated catalysts is not addressed.