Controllable nanoporous copper synthesized by dealloying metallic glasses: New insights into the tuning pore structure and applications

Abstract

It is a great challenge to explore a feasible inner factor that dominates the ligament/pore size of nanoporous metals (NPMs). Herein, the controllable nanoporous copper (NPC) ribbons synthesized by free-dealloying as-spun Cu50-xZr50Mx (x = 0 and 2.5 at.%; M = Al, Nb, Ag) metallic glasses (MGs). From insightfully understanding the correlation of the ligament sizes of NPC, the surface diffusivity of Cu atoms as well as the corrosion potential of additional elements (Al, Nb, Ag), it is firstly unveiled that the corrosion potential of additional elements in the examined etching media could be an inner factor for influencing the pore/ligament size of NPMs. The new findings rooting in the inherent nature of additional elements makes the design of NPMs with useful pore size much more feasible than ever. For further application of NPC with tunable ligament size, the suitable pore structure of NPC is effective in improving the dispersion of MnO2 nanoflakes or nanoflowers to form 3D porous MnO2@NPC composite electrodes. Density functional theory (DFT) further proves that the interaction of NPC and MnO2 results in the modification of the electronic structure and subsequently the improvement of the electrochemical performance. The NPC-supported MnO2 electrode presents much enhanced specific capacitance and cycling stability as compared to the MnO2 nanoparticles. At last, three symmetric supercapacitor (SC) devices connected in series could power up a green LED bulb for more than 55 min.