On the growth and mechanical properties of nanostructured cobalt foams by dynamic hydrogen bubble template electrodeposition

The growth mechanism of nanostructured cobalt foams prepared by hydrogen bubble template electrodeposition has been studied. To that end, cobalt foams have been synthesized under different electrodeposition times and studied with various characterization techniques, namely scanning electron microscopy (SEM) and confocal microscopy in reflection mode. In addition, the mechanical properties of the resulting foams have been tested by bending and tensile tests. To study the influence of chemical additives in the growth mechanism and final properties of the foams, agar-agar has been added to the electrolytic bath during foam preparation. Results evidence that the addition of agar has successfully modified the microstructure of the final foams, creating a denser porous structure with smaller pore area and reduced growth rate that translates into better mechanical properties. By studying the evolution of the microstructure under different deposition conditions, a growth model of cobalt metallic foams by dynamic hydrogen bubble template is proposed. This easy and scalable route paves the way to produce tailored foams for numerous applications that include, for instance, energy storage and energy conversion. [Display omitted] •Co nanofoams have been prepared by Dynamic Hydrogen Bubble Template-Electrodeposition.•Evolution of microstructure is monitored by Scanning Electron microscopy.•Porosity is controlled by modification of reaction time.•Morphology is modified by incorporation of Agar.•A growth Mechanism is proposed for DHBT-ED of metallic nanofoams.