Abstract
The effects of electroplating variables on the hydrogen evolving activity of Ni-P deposits were systematically examined using fractional factorial design (FFD), path of steepest ascent, and central composite design (CCD) coupled with the response surface method (RSM). The FFD study indicates that the main and interactive effects of temperature, pH, and NaH 2 PO 2 ·H 2 O concentration are the key preparation factors influencing the Ni-P cathode. Empirical models for apparent activity (i), specific activity (i/Ra), and phosphorus content (at %) are fitted against these three variables in the CCD study. These models, represented as contour diagrams, show that a Ni-P deposit with 7 P at % exhibits the maximum electrocatalytic activity.