Nickel foam was carefully cleaned by concentrated HCl solution (37 wt.%) in an ultrasound bath for 5 min in order to remove the surface oxide layer. And then rinse with deionized water and anhydrous ethanol to ensure the surface of the Ni foam was well cleaned.
Please be noted this thin nickel foam substrate is pressing-rolled (calendered) from the original 1.6mm thickness, you can order MTI's press rolling machine here and 1.6mm thickness nickel foam here to get the desired thickness range from 0.08mm to 1.6mm