Evaluation of NiAl LDH, Al(OH)3, and Zn(OH)2nanoparticle-based coating on nickel foam for hydrogen evolution from aqueous solution

Developing high-performance electrocatalysts for the large-scale hydrogen evolution reaction via electrochemical water splitting is essential. In this research, nickel-aluminum-zinc nanoparticles were deposited onto three-dimensional nickel foam (NiAlZn/NF) using a hydrothermal method. The structure and morphology of the synthesized electrocatalyst were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The crystalline nature was studied using high-resolution transmission electron microscopy (HRTEM). Also, the activity of the hydrogen evolution reaction was investigated using linear scanning voltammetry (LSV) in a 1 M potassium hydroxide (KOH) electrolyte. The coated samples were compared with the bare nickel foam substrate. The results showed the potentials required to create a current density of 10 and 100 mA/cm² for the 3Ni-4Al-1Zn specimen deposited on nickel foam are 196 and 479 mV, and for the 4Ni-3Al-1Zn are 233 and 484 mV, and for the 3Ni-3Al-1Zn, are 218 and 587 mV, and for the raw nickel foam, are 251 and 624 mV, respectively. Also, the electrochemical impedance spectroscopy (EIS) showed that the value of R_ct for 3Ni4Al1Zn, 4Ni3Al1Zn, 3Ni3Al1Zn, and nickel foam is 6.4, 10.2, 18, and 22.1 Ω, respectively. Besides, 3Ni4Al1Zn/NF also shows long-term stability lasting six hours. The R_ct value for the 3Ni4Al1Zn sample is lower than the rest, which indicates a better charge transfer during the electrochemical process. The results showed that the coated specimens performed better catalytic behavior in hydrogen generation than the bare nickel foam sample.