Tsai W.-HTang C.-HCheng I.-C.I-Chung Cheng2021-08-052021-08-052021406090https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102967934&doi=10.1016%2fj.tsf.2021.138628&partnerID=40&md5=c64a21a3177c87ebb25a78871518bc7chttps://scholars.lib.ntu.edu.tw/handle/123456789/576145A hierarchical structure featuring both nano- and macro- structure has emerged as prospective candidates for the application requiring high flow rates and specific surface area. A unique physical and mechanical behavior could be discovered by designing a special structure. A random orientated nanoporous copper thin film coated on a three-dimensional (3D) microporous periodical octet-truss lattice was utilized as a hierarchical structure to evaluate the mechanical and catalytic behaviors. Nanoporous copper films with ligament size ranging from 16 to 28 nm were synthesized using magnetron co-sputtering CuAl alloy films and subsequent dealloying process, while the octet-truss with a pore size of 120 μm was fabricated by digital light processing. The yield strengths of the octet-truss lattice with nanoporous Cu (L-NPC) films are 3 times higher than those of low-density bulk Cu or Cu films predicted by the Gibson-Ashby equation. The current densities and electrochemical surface area of the L-NPC films are also 10 times higher than those of octet-truss lattice with solid Cu films or NPC films coating on a two-dimensional substrate. In addition to the nano-scale pore size effect, the 3D polymer structure produced a high curly surface for NPC films to attach on the truss which could be the reason for the different mechanical and electrochemical behaviors. ? 2021 Elsevier B.V.Aluminum alloys; Binary alloys; Catalysis; Copper alloys; Pore size; Thin films; Trusses; Catalytic behavior; Copper films; Cu/Ti films; Hierarchical structures; Magnetron co-sputtering; Mechanical behavior; Nano-porous; Nano-porous coppers; Octet-truss lattice; Thin-films; Metallic filmsjournal article10.1016/j.tsf.2021.1386282-s2.0-85102967934