Conformal oxide nanocoatings on electrodeposited 3D porous Ni films by atomic layer deposition

Abstract

A versatile chemical synthesis procedure to obtain Al2O3 and Co2FeO4 nanolayers conformally coating a three-dimensional (3D) porous Ni film is presented. First, porous Ni is grown by hydrogen bubble template-assisted electrodeposition. Subsequently, Al2O3 and Co2FeO4 layers, with thickness ranging from 5 nm to 25 nm, are directly deposited onto the pore walls by atomic layer deposition, while maintaining the porous architecture and magnetic properties of the Ni scaffold. The crystal structure, thickness and distribution of elements within the composite coatings are investigated in detail. The resulting magnetic and wettability properties are assessed. Contact angle tests reveal that 3D porous Ni films become more hydrophilic after coating with Al2O3 or Co2FeO4. From a technological point of view, the obtained composite porous films could be appealing for applications like magnetically-actuated micro/nano-electromechanical systems (MEMS/NEMS) or bio-MEMS/NEMS, among others.

Electrodeposited Ni-Based Magnetic Mesoporous Films as Smart Surfaces for Atomic Layer Deposition: An “All-Chemical” Deposition Approach toward 3D Nanoengineered Composite Layers

“…30−32 In fact, we proposed the combination of ED and ALD to prepare composite layers consisting of 3D macroporous magnetic metals coated with metal oxide nanolayers, i.e., Ni/Al 2 O 3 and Ni/Co 2 FeO 4 . 33 It was demonstrated that both the porosity and the magnetic properties of the electrodeposited metallic matrix were maintained after the ALD step under optimized ALD conditions. However, the ALD deposition was only tested on metallic films exhibiting large pore sizes, on the order of 5−15 μm.…”

“…Atomic layer deposition (ALD) turns out to be a powerful deposition technique that allows not only precise control over the composition of the deposited materials, but also these can continuously coat high aspect-ratio substrates [30][31][32] . In fact, we proposed the combination of ED and ALD to prepare composite layers consisting of 3D macroporous magnetic metals coated with metal oxide nanolayers, i.e., Ni/Al2O3, Ni/Co2FeO4 33 . It was demonstrated that both the porosity and the magnetic properties of the electrodeposited metallic matrix were maintained after the ALD step under optimized ALD conditions.…”

“…For example, 3D macroporous Ni films prepared by the hydrogen bubble templating approach can function as scaffolds to anchor electrodeposited Co­(OH) 2 nanoflakes or sputtered Si to produce nanoporous composites with superior supercapacitor and electrochemical performance. , In the case of mesoporous materials of metallic nature, an appropriate technique should be carefully selected in order to conformally coat the mesopores with a second-phase material while avoiding or minimizing its oxidation and eventual pore collapse. Atomic layer deposition (ALD) turns out to be a powerful deposition technique that allows not only precise control over the composition of the deposited materials, but also these can continuously coat high-aspect-ratio substrates. − In fact, we proposed the combination of ED and ALD to prepare composite layers consisting of 3D macroporous magnetic metals coated with metal oxide nanolayers, i.e., Ni/Al 2 O 3 and Ni/Co 2 FeO 4 . It was demonstrated that both the porosity and the magnetic properties of the electrodeposited metallic matrix were maintained after the ALD step under optimized ALD conditions.…”

Electrocatalytic Activities of Macro- Porous Nickel Electrode for Hydrogen Evolution Reaction in Alkaline Media

“…From electrochemical data presented in Table 3, electrocatalytic behavior could be enhanced by decreasing pore size. So that, According to Abdel-Karim and Halim [10,11], the βc for different nickel-based alloys was in range from 50 to 190. So that micro porous Ni deposits have a high catalytic value as it compares with other works.…”

“…Porous structures, with much larger surface area-to-ratio compared to their fully dense counterparts, are very appealing to enhance certain physical-chemical properties. Nanostructured porous materials have received considerable attention in areas like batteries [11], electrocatalysis [12], super-capacitors [13], or magnetic micro/nanoelectromechanical systems.…”