Design of Experiments for Pulse Reverse Electrodeposition of Graphene Oxide toward Hydrogen Evolution Reaction

Surface active sites of pulse reverse electrodeposited graphene oxide (PREGO) coating is optimized by design of experiments approach (central composite design). Applied current density (i), cathodic (Tc) and anodic (Ta) pulse durations, and total electrodeposition time (Tt) are selected to interpret the hydrogen evolution reaction (HER). The analyses of variance (ANOVA) are carried out on the outcomes of the designed experiments. A definitive linear relationship without any significant interaction was introduced as the best prediction model. Moreover, the results indicating the Ta and Tc are the most significant model terms. The best desirable value of the exchange charge on the cyclic voltammetry (CV) was obtained equal to 36785.43 μC which collected on the i, Tc, Ta and Tt of 235.62 mA cm−2, 7.75 ms, 3.25 ms (f = 100 Hz) and 225 s respectively. Various experiments such as X-ray diffraction, Fourier transform infrared, Raman, and electrochemical impedance spectroscopies as well as the field emission scanning electron microscopy and dynamic polarization test were carried out to characterize the optimized thin film. The corrosion resistance enhanced approximately 6.9 times accompanied by an inhabitation efficiency of 85.53%. Besides, the Rf value equal to 116.36 illustrates 3D graphene has a high potential in the HER field.