Jem 2100

A modified Stöber method was used to synthesize the Cu–Zn BGns.^[49
] First, TEOS was mixed in ethanol (solution A) with ammonia, deionized water (DI‐H₂O), and ethanol (solution B) with stirring. Calcium nitrate tetrahydrate was added after 30 min. Subsequently, zinc nitrate was added, and the reaction was allowed to proceed for 90 min before centrifugation at 8000 rpm for 15 min. The deposits were collected, washed with DI‐H₂O thrice, and calcined at 700 °C for 2 h to obtain Zn‐BGns. Next, the Zn‐BGns were dissolved in DI‐H₂O (solution C) with ammonia, CTAB, ethanol, and DI‐H₂O (solution D) by stirring for 30 min, followed by a reaction with TEOS for 15 min. Next, we added Cu/ascorbic acid complex precursors,^[50
] and the mixture was stirred for 24 h. The colloids were centrifuged at 8000 rpm for 15 min, collected, washed with DI‐H₂O twice and ethanol once, and dried at 60 °C overnight. Finally, Cu–Zn BGns were calcined at 700 °C for 2 h. The morphology and constituents of nanoparticles were determined using SEM (S4800, Hitachi, Japan) and TEM (JEM2100, Hitachi, Japan) with EDS. The chemical composition and state of the nanoparticles were analyzed using XRD (Bruker, Billerica, USA), XPS (ESCALAB 250Xi, Thermo Fisher, USA), and FTIR (Magna‐IR 750, Thermo Fisher, USA). DLS measurements were performed by a Wyatt Mobius DLS instrument.

The phase composition and microstructure of precursor powder, reduced composite powder and the sintered alloy were characterized by X-ray diffraction (XRD, D/MAX-2500) with Cu Kα radiation, field emission scanning electron microscopy (SEM, Hitachi model No. S 4800), and transmission electron microscopy (TEM, JEM-2100), respectively. High-angle annular dark-field (HAADF) STEM images were taken on a JEOL JEM-ARM200F instrument using an annular-type detector. The S/TEM specimens were firstly ground to 20 μm on SiC abrasive papers and then thinned on an ion beam thinner (Gatan-PIPS695). Electron backscatter diffraction pattern (EBSD) mappings of cWY alloys were collected using a field emission scanning electron microscopy (SEM, JSM-7800F) equipped with a CRYSTAL detector (NordlysMax²). The specimens for EBSD characterization were firstly ground on SiC abrasive papers. Then they were further polished on a metallographic lapping (UNIPOL-820) with the aid of diamond polishing spray, followed by electrolytic polishing in 5% sodium hydroxide aqueous solution with a constant voltage of 11 V and a current density of 3 mA/mm².

Scanning electron microscopy (SEM, Hitachi SU-8010) and transmission electron microscopy (TEM, JEM-2100) measurements were taken to estimate the morphology and internal structure of samples. X-ray diffraction (XRD) patterns were obtained by Rigaku MiniFlex 600 (Cu Kα radiation). Thermogravimetric analysis (TGA) was performed by the simultaneous thermal analysis instrument (METTLER TOLEDO TGA/DSC 3+). Micromeritics ASAP 2020 Plus HD88 was employed to measure N₂ adsorption–desorption curves. The surface chemistry was analyzed based on X-ray photoelectron spectroscopy (XPS) in Thermo Fisher Scientific Escalab 250Xi.

The amorphous SiNPs used in the experiments were prepared by the Stöber method as previously described [35 (link)]. The particle shape and size was observed by scanning electron microscopy (SEM; Hitachi S-4800, Japan) and transmission electron microscopy (TEM; JEM2100, Japan). Based on the TEM results, the particle size distribution was analyzed through Image J software. The hydrodynamic size and Zeta potential of SiNPs in deionized water were measured by Zetasizer (Malvern Nano-ZS90, UK). Moreover, an inductively coupled plasma atomic emission spectrometry (ICP-AES; Agilent 720, USA) was used for the purity detection of the synthesized SiNPs, and a gel-clot limulus amebocyte lysate (LAL) assay kit (Bokang, Zhanjiang, China) for endotoxin measurement. In addition, the stock suspension of SiNPs were firstly dispersed by a sonicator (160 W, 20 kHz, 5 min; Bioruptor UCD-200, Belgium), and then diluted by the corresponding exposure media, 0.9% saline (in vivo test) or DMEM (in vitro test).