Aztec

ATR-FTIR spectra were recorded at a resolution of 4 cm⁻¹ over the 4000–700 cm⁻¹ range using a NICOLET IZ10 spectrometer (Thermo Scientific, Waltham, MA, USA) equipped with a germanium ATR crystal and a single reflection angle 45° horizontal ATR accessory. The UV-Vis spectroscopic analysis was performed using a DR 3900 UV-Vis spectrophotometer (Hach Lange, Loveland, CO, USA) equipped with 1 cm quartz cuvettes. High-resolution transmission electron microscopy (HR-TEM) analysis was carried out using transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) system (Titan 80-300, FEI, city, state abbrev if USA, country) with a super twin-lens operated at 300 kV and equipped with an annular dark field detector. The presence of various elements in the obtained nanoparticles was analysed using energy-dispersive X-ray spectroscopy (EDX, Aztec, Oxford Instruments, Abingdon, UK). ICP-MS (Elan 6000, Perkin Elmer, Waltham, MA, USA) was used to determine the Pd/Pt concentration.

Primary particle size, shape, and chemical characterization were determined by FE-SEM (JSM-7100F, JEOL, Tokyo, Japan), equipped with EDS (Aztec, Oxford Instruments, Abingdon, UK). Zeta potentials and hydrodynamic radii of particles (1 mg/mL) were measured with Zetasizer Nano System (Malvern Instruments, Worcestershire, UK) after stirring for 30 min, sonication for 15 min (Bransonic 5800, Branson Ultrasonics, Danbury, CT, USA), and dilution (0.1 mg/mL).

The microstructure of materials was studied using an optical microscope (OM-Olympus PME3) and a scanning electron microscope (SEM—TESCAN LYRA) equipped with an EDS analyzer (OXFORD Instruments AZtec). Prior to the observations, the samples were ground using SiC grinding papers (P400–P2000), then polished with diamond paste D2 (UR-diamant, 2 µm) and finally polished on suspension Etosil E (Metalco, 0.06 µm). The average grain size was calculated using image analyses (ImageJ) on several images. For each grain, the Feret′s diameter was measured. The phase composition of the materials was determined by X-ray diffraction. Measurements were made at ambient temperature using the X’Pert3 Powder instrument with Bragg–Brentano geometry equipped by a Cu anode (λ = 1.5418, U = 40 kV, I = 30 mA). The evaluation of the results was performed using HighScore Plus 4.0 and Topas 3 software. The names and reference codes of the evaluated phases in PDF 4 database were Zn (01-078-9363), Mg₂Zn₁₁ (04-007-1412), MgZn₂(04-008-6026) and Mg (04-013-4129). The details of the microstructure were studied by transmission electron microscope (TEM-EFTEM Jeol 2200 FS, accelerating voltage 300 kV, LaB₆). The samples for TEM were prepared using the Gatan PIPS polishing system with Ar ions (Gatan, Pleasanton, CA, USA).