Gulmaira Partizan

In this study, nitrogen-doped graphene (NG) films were synthesized on copper foil sur-faces by chemical vapor deposition (CVD), and their anti-corrosion properties were comprehensively investigated. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) results showed that the graphene layer was uniformly formed and nitrogen atoms were successfully incorporated. Raman spectroscopy revealed that the sample obtained on a 30 μm thick copper foil had a high structural quality (low ID/IG value). Electrochemical measurements showed that the NG coatings significantly reduced the corrosion current density and rate compared to pure copper. In short-term tests, the highest inhibition efficiency (91.5%) was observed for the sample synthesized on a 200 μm thick copper foil. In long-term (up to 2 months) seawater immersion tests, the inhibition efficiency decreased slightly over time, but the NG coatings showed much higher anti-corrosion properties than pure copper at all times. Overall results proved that nitrogen-doped graphene is a potential material in protecting metals from long-term corrosion, not only in seawater but also in harsh environments.

This study presents a density functional theory (DFT) investigation of the electronic response of graphene doped with various atoms (B, N, Al, Si, S, Ga) under biaxial strain. The calculations were performed using the PBE exchange–correlation functional within the generalized gradient approximation (GGA), as implemented in the DMol³ code. The Fermi energy was used as the primary indicator to evaluate strain sensitivity across a deformation range from −0.05 to +0.05. The results reveal a strong dependence of the electronic response on the type of dopant. Ga- and Al-doped graphene systems exhibit the most pronounced Fermi level shifts, up to 0.6 eV, indicating high sensitivity to mechanical strain. In contrast, B- and N-doped graphene show more moderate but stable and linear changes, which may be advantageous for predictable sensor behavior. These findings highlight the critical role of dopant selection in engineering strain-responsive graphene materials and support a design framework for their integration into high-performance flexible electronics and sensing applications.

This article presents the results of experiments on the synthesis of carbon nanofibers by thermal chemical vapor deposition using copper nanopowders obtained by electric explosion of wire as catalysts. Stable growth of carbon nanofibers was carried out at temperatures significantly lower than normally used. The process parameters that are optimal for low-temperature growth of carbon nanofibers have been identified during the performed experiments. The synthesized samples have different diameters and morphology (from spiral to direct). Copper clusters are both at the ends and inside the fibers. The results of IR spectroscopy indicate that the structure of the obtained carbon nanofibers is polymeric. X-ray analysis revealed the presence of a halo on the diffraction patterns at small values of the angle 2θ, which proves that the grown structures have an amorphous nature. There are no groups that are responsible for long-range order in all Raman spectra. Studies by transmission electron microscopy showed that nanostructures do not have an internal channel and nanofibers are solid.

This work presents the results of experiments on synthesis of carbon nanostructures (CNs) by the method of thermal chemical vapor deposition using iron nanopowders obtained by the method of electrical explosion of wires as catalysts. To study the process of nucleation and growth of individual carbon nanostructures, experiments were conducted not only on nanopowders, but also on the separated clusters. To determine the optimum conditions of the carbon nanostructures synthesis and lower temperature limit, experiments were performed at different temperatures (300-700°C) and pressures (100-400 mbar). The experiments have shown that the lower temperature limit for carbon nanostructures synthesis on the iron nanopowders is 350°C and in this process the growth of carbon nanostructures is not so massive. Stable growth of carbon nanostructures for nanopowders began from 400°C during the entire range of pressures. The analysis of Raman spectroscopy showed that the most optimum conditions for obtaining nanotubes of high quality are P = 100 mbar and T = 425°C.

Исследование электровзрывных нанопорошков никеля