Novel method of powder-based processing of copper nanofoams for their potential use in energy applications

Abstract This paper discusses a new method of powder-metallurgy processing to produce regular-structured Cu nanofoams or irregular-structured Cu foams containing both micropores and nanopores. Coarser Cu nanofoam struts (approximately 2.5 times larger) formed in the ribbon samples of the foams subjected to additional sintering at 900 °C after initial lower-temperature sintering at 450 °C than those formed in the ribbon samples of the foams subjected to additional sintering at 700 °C. Furthermore, a much higher degree of strut continuity was observed in the Cu nanofoam sintered at 900 °C, which should improve the ductility and structural integrity of the Cu nanofoam. This study can be considered as a framework for using a simple method of powder-based dealloying to produce nanoporous and micro/nanoporous metallic foams for a variety of energy-based applications requiring metallic foam materials with a high density of specific surface area. Although the dealloying process of achieving Cu nanofoams is not new, this powder-based method has significant implications because often a difficult and expensive material shaping process can be avoided by forming the precursor alloy with a near-net shape geometry in the method.