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This post was last edited by Shaobin Fluid on 2026-5-19 at 14:06. Ains studied the growth mechanism of graphene on the surface of tantalum. It has been proven that the growth of graphene is achieved through the formation of tantalum carbide, which possesses catalytic properties for the cracking of hydrocarbons. We found that excess carbon, which does not participate in the formation of carbides, forms a self-limiting layer of graphene on the surface. Tantalum carbide and graphene layers provide an effective protective layer against chemical corrosion and high-temperature oxidation. To purify copper from contamination and corrosion at high temperatures and to enhance its thermal and electrical conductivity, the growth of graphene on copper is currently being widely studied. To utilize the barrier properties of graphene, it is highly beneficial to extend its growth on other materials. For example, it is very useful to be able to grow graphene on metals such as uranium, rhenium, and tantalum. This material is used as a target to generate a beam of radioactive ions through radiation (usually protons). However, it is often necessary to protect these targets from aging and oxidation. Graphene is an ideal protective layer, as its single-atom thickness (which greatly reduces the likelihood of interactions between particle layers) and the kinetic energy distribution of nuclear recoil fragments mean that graphene has no effect on them. Experiment 1 Figure 1. Optical images and Raman data demonstrate the optimal conditions for growing graphene on tantalum foil. (a) and (b) correspond to the optical images and Raman spectra of the tantalum surface after the graphene growth process on the unetched and etched foils, respectively. The scale is 50 meters. Optical micrographs of the tantalum surface after chemical vapor deposition of graphene under different pressures and temperatures. Pure tantalum has a shiny color, but it turns yellow when the surface is covered with a carbide-graphene heterostructure. The samples in the red frame show the growth conditions under which different graphene peaks were observed. All images are 50 m in size. Data obtained from the Raman spectrum of the protruding sample. To grow a single-layer or few-layer graphene with a surface coverage of 90%, the optimal temperature and pressure are 1150°C and ~100 Torr, respectively. Ains studied the growth mechanism of graphene on tantalum surfaces and its barrier properties. Our research shows that it is indeed possible to grow high-quality graphene on tantalum foil. However, its growth mechanism is different from that of nickel or copper. In the initial stage, a thin layer of tantalum carbide is formed, which then serves as a foundation for the growth of graphene. The combination of graphene and tantalum carbide provides excellent corrosion protection for tantalum foil. 2 Fig. 2. Raman spectra of graphene grown on tantalum foil at different pressures (a) and temperatures (b). In Figure (b), it can be clearly seen that the quality of graphene is related to the growth temperature. As the temperature increases, the intensity of the D peak (~1341 cm-1) decreases, while the intensity of the 2D peak (~2600 cm-1) increases. The black dashed line shows the position of the peak attributed to tantalum oxide (~ 660 cm-1). As the temperature increases, a carbide peak appears (blue dashed line). Further increases in temperature lead to the widespread presence of carbide peaks. At low temperatures, only the tantalum oxide peak at 660 cm-1 can be seen, as shown in Fig. 2b. At higher temperatures, new peaks appear at 290 cm-1, 600 cm-1, and 770 cm-1; these peaks may be related to tantalum carbide and begin to dominate, indicating that the mechanism of graphene growth involves the formation of tantalum carbide as a precursor for graphene. 3 Fig. 3. Characterization of the TAc/graphene surface grown on tantalum foil. (1) Scanning electron microscope image of the cross-section of tantalum-coated stainless steel foil fibers after chemical vapor deposition experiments. Enlarged view of the unique cellulose triacetate layer (thickness approximately . 400 nm). (c) XRD spectrum of tantalum foil with a distinct TaC peak. Elemental content analysis (from an energy spectrometer) shows the penetration depth of carbon into the tantalum foil during chemical deposition: 1–foil surface, 2–cross-section near the surface, 3–overall tantalum spectrum. Both brightness contrast and elemental analysis can clearly identify tantalum carbide. Grown for one hour using optimal parameters (temperature = 1150°C, pressure = 200 MPa), the thickness of tantalum is approximately 400 nanometers). Therefore, we can confirm that the growth mechanism of graphene on tantalum differs from that in metals that do not form carbides: it occurs through a precipitation mechanism in metals with high carbon solubility such as nickel, or via catalytic and self-limiting growth on the surfaces of metals with low carbon solubility, while exhibiting certain catalytic activity for hydrocarbon cracking. Figure 4 shows photographs and optical images of the tantalum foil resulting from the chemical corrosion test (treated in a 30% sodium hydroxide aqueous solution at 70°C for 20 hours). Panels (a-f) are the photos and optical images before the corrosion test, while panels (g-l) are the photos and optical images after corrosion. (a) Photo of the original tantalum-plated stainless steel foil, (b) tantalum foil with graphene etched in an oxygen plasma, (c) tantalum with a protective graphene layer; panels (d-f) show the corresponding optical micrographs of panels (a-c). The image on panel (g-l) is the same as that on (a-f), but it was taken after the corrosion test. The scale for (d-f) is 50 meters, while the scale for (j-l) is 100 meters. Before and after the corrosion test, Raman spectroscopy of the tantalum surface was performed on the samples located on plates b, c, h, and I in Figure 4. As a result, strong etching occurred on the surfaces of the unprotected samples (due to natural oxides and the tantalum itself). For the samples protected with carbides and graphene, no etching was observed, and graphene was found on the surface after the procedure. In summary, the growth of graphene on titanium is achieved through the initial formation of carbides, which serve as a catalytic surface for graphene deposition. This combination of graphene and carbides creates a highly effective barrier against corrosion and oxidation; meanwhile, the deposition of tantalum on the surface of graphite products effectively prevents contamination and corrosion, providing an optimal solution for extending their service life.