Ni-Mo allays have a wide appilication due to their ability to provide low hydrogen evolution overpotentials. In this project Ni-Mo coatings were deposited from a bath contains Sodium Citrate, Nickel Sulphate and Sodium Molybdate. At first, the effect of parameters such as pH from 7 to 10.5, temperatures (24°C and 40°C), current density (10, 30 and 100 mA/cm 2 ), present of ammonia in bath and coating annealing were investigated. Using EG G potentiostat model 263A and EG G AC responser Model 1025, polarisation and Electrochemical Impedance Spectroscopy (EIS) curves were plotted. Morphology and chemical composition were investigated using Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS), respectively. The results show that polarisation curves were shifted to the left hand with decreasing temperature and increasing pH. EIS results showed that the second time constant observed at low temperature, indicating on diffusion controlled behavior of deposition process, was disappeared by increasing the temperature from ambient temperature (24°C) to 40°C or increasing pH from 7 to 9. Increase of coating compactness by increasing temperature and pH was detected by SEM observations that pH has a made strong effect on the properties of deposits. When pH increase from 8 to 10.5, Mo content of deposit decreased from 45 wt% to 20.4 wt%. Increasing pH to 10.5 created a diffusion controlled regime. Corrosion and electrocatalytic behavior of deposits in 10 wt% NaOH was also investigated. The results showed that Ni-Mo deposits show active, passive and traassive regions and has a high resistance to pitting corrosion. By adding Mo to Ni, its electrocatalytic behavior could be improved, but raising the Mo percentage greater wt%, reduced its electrocatalitic properties
