The present disclosure pertains to electrodes that include a nickel-based material and at least one porous region with a plurality of nickel hydroxide moieties on a surface of the nickel-based material. The nickel-based material may be a nickel foil in the form of a film. The porous region of the electrode may be directly associated with the surface of the nickel-based material. The nickel hydroxide moieties may be in crystalline form and embedded with the porous region. The electrodes of the present disclosure may be a component of an energy storage device, such as a capacitor. Additional embodiments of the present disclosure pertain to methods of fabricating the electrodes by anodizing a nickel-based material to form at least one porous region on a surface of the nickel-based material; and hydrothermally treating the porous region to form nickel hydroxide moieties associated with the porous region.