Crystallographic and morphological characterization results
In this report, we focused on the crystallographic and morphological characterization of as-prepared multi-metal materials, using X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM).
(1) X-Ray crystal structure of purified MM25C75M powder was determined using X-ray diffraction (PANalytical Empyrean; Cu Kα radiation with wavelength equal to 1.5406 Å and two-dimensional area detector). The XRD results showed the diffraction pattern of MM25C75M with peaks at 2Ɵ = 178.993°, 33.182°, 37.963°, 50.414°, 58.766°, 61.944°, and 72.019° well matched with brucite Mg(OH)2 (JCPDS 44-1482). No additional phase peak was observed in the XRD patterns. The peak position of MM25C75M (5000 µg/ml metallic Cu, 15000 µg/ml metallic Mg) along (001) direction was shifted to the lower value (2Ɵ = 17.993°) in comparison to reagent-grade Mg(OH)2 (2Ɵ = 18.665°), possibly due to lattice expansion. This lattice expansion could be attributed to the higher ionic radius of Cu compared to the ionic radius of Mg. It indicates that Cu ions substituted Mg ions in the MM25C75M without changing the brucite Mg(OH)2 structure.
(2) The morphology of MM25C75M and MM10C45M45Z (5000 µg/ml metallic Cu, 22500 µg/ml metallic Mg, 22500 µg/ml metallic Zn) was observed under SEM. MM25C75M showed a pyramid-like structure. The particle size was around 253 nm. MM10C45M45Z were small lamellar shaped flakes and the size was around 100 nm. The addition of a Zn caused changes in the morphology, suggesting interactions among the metals and structural reorganization. SEM data can be correlated to the average particle size obtained by Dynamic Light Scattering (DLS) technique previously reported.