The mechanical and catalytic behavior of nanoporous copper film on octet-truss lattice via magnetron sputtering

A 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 ?m 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 LNPC 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.

Automated summary

The hierarchical structure using nanoporous copper films and a three-dimensional lattice structure shows enhanced mechanical properties and catalytic activities. Compared to traditional copper materials, the yield strength is increased by 3 times, while the current density and electrochemical surface area are increased by 10 times.