Phase Equilibria of the Co-Cu-Mo System at 900 and 1100 °C

Spontaneously separated intermetallic Co3Mo from nanoporous copper as versatile electrocatalysts for highly efficient water splitting

“…X-ray diffraction (XRD) characterization of nanoporous Co 3 Mo/Cu electrode verifies the hybrid structure, with two sets of diffraction patterns ( Fig. 1g): the evident diffraction peaks at 2θ =~40.6°,~44.0°, and~46.4°corresponding to the (200), (002), and (201) planes of intermetallic Co 3 Mo in space group P 63/mmc (JCPDS 29-0488) 37,42,43 , and the ones else assigned to Cu (JCPDS 04-0836). This is in contrast with the XRD patterns of nanoporous Cu with/without Mo or Co incorporation, wherein they cannot be detected due to either too little or too small clusters on the Cu ligaments despite their similar geometric structure of nanoporous electrodes ( Supplementary Figs.…”

“…Therein, both the hierarchical structures and components are controlled by making use of quasi-eutectic Cu 12−x−y Co x Mo y Al 88 (x = 0 or 3, y = 0 or 1 at%) alloy precursors ( Supplementary Fig. 1), which are primarily composed of immiscible multiphase α-Al and CuAl 2 without/with additional intermetallic Co 3 Mo 36,37 , Co 2 Al 9 , or MoAl 12 ( Supplementary Fig. 2).…”

“…It displays a hierarchical nanoporous Cu skeleton with~300 nm large channels and~25 nm small nanopores. Owing to the poor miscibility of intermetallic Co 3 Mo with Cu matrix 37,42 , ultrasmall intermetallic Co 3 Mo nanoparticles with diameter of~10 nm are spontaneously separated and in situ integrated on the interconnective Cu ligaments as a result of the Cu surface diffusion during the etching processes ( Fig. 1b).…”