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Graphitic carbon nitride (G-C3N4) and NiS-NiO/G-C3N4 nanocomposite have been synthesized via combustion and hydrothermal techniques, respectively. The chemical and morphological properties of these materials were confirmed using different analytical methods. SEM confirms the formation of G-C3N4 sheets containing additional petal-like shapes of NiS-NiO nanoparticles. The electrochemical testing of NiS-NiO/G-C3N4 symmetric supercapacitors is carried out from 0.6 M HCl electrolyte. Such testing includes charge/discharge, cyclic voltammetry, impedance, and supercapacitor stability. The charge/discharge time reaches 790 s at 0.3 A/g, while the cyclic voltammetry curve forms under a high surface area. The produced specific capacitance (CS) and energy density values are 766 F/g and 23.55 W.h.kg−1, correspondingly.

Hydrogel nanocomposites are attracting increasing attention in field of biology owing to their unique properties. The present work focuses on the fabrication and characterization of novel hydrogel nanocomposite systems in which silver nanoparticles (AgNPs) are embedded in a carrageenan (

Graphitic carbon nitride (G-C3N4) was synthesized through the direct combustion of urea in the air. The CoS-Co

The melt-quenching technique was used to synthesize tellurite glasses of the chemical composition 80TeO

Herein, an optoelectronic device synthesized from a CuFeO

The laser-induced breakdown spectroscopy (LIBS) technique was performed on polymers to study the neutral and ionic emission lines along with the CN violet system (B

MoO

During the current outbreak of the novel coronavirus disease 2019 (COVID-19), researchers have examined several antiviral drugs with the potential to inhibit the proliferation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antiviral drug acyclovir (AVR), which is used to treat COVID-19, in complex with methyl-β-cyclodextrin (Mβ-CD) was examined in the solution and solid phases. UV-visible and fluorescence spectroscopic analyses confirmed that the guest (AVR) was included inside the host (Mβ-CD) cavity. A solid inclusion complex of AVR was prepared by co-precipitation, physical mixing, kneading, and bath sonication methods at a 1:1 ratio of Mβ-CD:AVR. The prepared Mβ-CD:AVR inclusion complex was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analysis. Phase solubility studies indicated the Mβ-CD:AVR inclusion complex exhibited a higher stability constant and linear enhancement in AVR solubility with increasing Mβ-CD concentrations.

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In this research, we studied the performance analysis of inductively coupled radiofrequency plasma “RF-ICP” torch used in multi-material processing. A 2D numerical model built with COMSOL Multiphysics was used to study the discharge behavior and evaluate the overall efficiency transmitted into the plasma system. The temperature and velocity flow of the plasma were investigated. The numerical results are consistent with previous experimental studies. The temperature and velocity profiles are represented under a wide range of RF power and for different sheath gas flow rates. With increasing power, the radial peak temperature typically shifts towards the wall. The resistance of the torch rises whereas the inductance diminishes with increasing RF power. The overall dependency of the coupling efficiency to the RF power is also estimated. The stabilization of the plasma flow dependency to the sheath swirl flow was investigated. The incorporation of Helium (0.02%) into an Argon gas was established to minimize the energy lost in the sidewall. The number and spacing of induction coil numbers affects the temperature and flow field distribution. A valuable approach to designing and optimizing the induction plasma system is presented in the proposed study. The obtained results are fundamental to specify ICP torch design criteria needed for multi-material processing.

The laser-induced breakdown spectroscopy (LIBS) technique was performed on polymers to study the neutral and ionic emission lines along with the CN violet system (B2Σ+ to X2Σ+) and the C2 Swan system (d3 Пg–a3 Пu). For the laser-based emission analyses, the plasma was produced by focusing the laser beam of a Q-switched Nd: YAG laser (2ω) at an optical wavelength of 532 nm, 5 ns pulse width, and a repetition frequency of 10 Hz. The integration time of the detection system was fixed at 1–10 ms while the target sample was positioned in air ambiance. Two organic polymers were investigated in this work: nylon and nylon doped with ZnO. The molecular optical emission study of nylon and doped nylon polymer sample reveals CN and C2 molecular structures present in the polymer. The vibrational emission analysis of CN and C2 bands gives information about the molecular structure of polymers and dynamics influencing the excitation structures of the molecules. Besides, it was further investigated that the intensity of the molecular optical emission structure strongly depends on the electron number density (cm−3), excitation temperature (eV), and laser irradiance (W/cm2). These results suggest that LIBS is a reliable diagnostic technique for the study of polymers regarding their molecular structure, identification, and compositional analysis.

MoO3 thin films are fabricated using nebulizer spray pyrolysis technique, which is doped with Fe at various concentrations of 1, 2, 3, and 4% for ammonia gas sensors application at room temperature. X-ray diffraction (XRD) study confirms the growth of the crystal by Fe doping up to 3%, nano rods shape morphology of the thin film samples observed by field emission scanning electron microscope (FESEM), reduction in bandgap is evidenced via UV-VIS spectrophotometer. Gas sensing study is performed using gas analyzing chamber attached with Keithley source meter. Since 3% Fe doped MoO3 sample displayed nano rods over the film surface which exhibits highest sensitivity of 38,500%, in a short period of raise and decay time 54 and 6 s. Our findings confirms that the 3% Fe doped MoO3 films suitability for ammonia gas sensing application.

Multiphase hexagon and flower-shaped structures of NiO nanocomposites have been prepared with different metal ions (Ce, Cu, Gd, Mn and Y) using facile and low-cost co-precipitation method. The optical, structural, morphological, and magnetic properties of the synthesized nanostructures have been investigated. The XDR measurement reveals the coexistence of several crystal structures like cubic, monoclinic, tetragonal, and orthorhombic which unveils the formation of polymorphism in the nanocomposites with high crystallinity. A wideband has been located in the FT-IR spectra at around 600 cm−1 revealing the metal oxide (M-O) phase formation. DRS exhibits four large and intense absorption bands at 260, 380, 420, and 720 nm in the UV and visible domains assigned to the nanocrystalline phases of NiO, CuO, CeO, and MnO, respectively. SEM images of metal-doped nickel oxide nanocomposites show a white sponge, semi-spherical, flower-like, and hexagon-shaped particles of 15 nm size. TEM result establishes a smooth surface for samples grown from gadolinium and yttrium, contrary to other samples made off cerium and manganese demonstrate a rough surface. A ferromagnetic tendency has been located for samples prepared from copper, manganese, and gadolinium-based NiO nanocomposites with coercivities of 132, 113, and 26 Oe, correspondingly. Photodiode characteristics were also investigated on the developed devices. These outcomes signify their use in spintronic and optoelectronic industries.

A three-dimensional numerical modelling of a time-dependent, turbulent thermal plasma jet was developed to synthetize silicon nanopowder. Computational fluid dynamics and particle models were employed via COMSOL Multiphysics®v. 5.4 (COMSOL AB, Stockholm, Sweden) to simulate fluid and particle motion in the plasma jet, as well as the heat dependency. Plasma flow and particle interactions were exemplified in terms of momentum, energy, and turbulence flow. The transport of nanoparticles through convection, diffusion, and thermophoresis were also considered. The trajectories and heat transfer of both plasma jet fields, and particles are represented. The swirling flow controls the plasma jet and highly affects the dispersion of the nanoparticles. We demonstrate a decrease in both particles’ velocity and temperature distribution at a higher carrier gas injection velocity. The increase in the particle size and number affects the momentum transfer, turbulence modulation, and energy of particles, and also reduces plasma jet parameters. On the other hand, the upstream flame significantly impacts the particle’s behavior under velocity and heat transfer variation. Our findings open the door for examining thermal plasma impact in nanoparticle synthesis, where it plays a major role in optimizing the growth parameters, ensuring high quality with a low-cost technique.

Plasma parameters of radiofrequency discharge generated at low pressures in an argon-oxygen mixture addressed for biomedical surface sterilization have been optimized. Numerical results illustrate the density distributions of different species and electron temperatures during the electrical discharge process. The current discharge acting in the abnormal range decreases at higher oxygen gas flow rates. The temperature of electrons drops with pressure while it rises by adding oxygen. Nevertheless, electron density displays an adverse trend, exhibited by the electron’s temperature. The average particle density of the reactive species is enhanced in Ar/O2 compared to He/O2, which ensures a better efficiency of Ar/O2 in sterilizing bacteria than He/O2. The impact of oxygen addition on the discharge mixture reveals raised oxygen atom density and a reduction in metastable oxygen atoms. A pronounced production of oxygen atoms is achieved at higher frequency domains. This makes our findings promising for biomedical surface sterilization and leads to optimal parameter discharges used for sterilization being at 30% of oxygen gas ratio and 0.3 Torr pressure.

Graphene has been intensively studied in recent years in order to take advantage of its unique properties. Its synthesis on SiC substrates by solid-state graphitization appears a suitable option for graphene-based electronics. However, before developing devices based on epitaxial graphene, it is desirable to understand and finely control the synthesis of material with the most promising properties. To achieve these prerequisites, many studies are being conducted on various SiC substrates. Here, we review 3C-SiC(100) epilayers grown by chemical vapor deposition on Si(100) substrates for producing graphene by solid state graphitization under ultrahigh-vacuum conditions. Based on various characterization techniques, the structural and electrical properties of epitaxial graphene layer grown on 3C-SiC(100)/Si(100) are discussed. We establish that epitaxial graphene presents properties similar to those obtained using hexagonal SiC substrates, with the advantage of being compatible with current Si-processing technology.

Graphene has been intensively studied in recent years in order to take advantage of its unique properties. Its synthesis on SiC substrates by solid-state graphitization appears a suitable option for graphene-based electronics. However, before developing devices based on epitaxial graphene, it is desirable to understand and finely control the synthesis of material with the most promising properties. To achieve these prerequisites, many studies are being conducted on various SiC substrates. Here, we review 3C–SiC(100) epilayers grown by chemical vapor deposition on Si(100) substrates for producing graphene by solid state graphitization under ultrahigh-vacuum conditions. Based on various characterization techniques, the structural and electrical properties of epitaxial graphene layer grown on 3C–SiC(100)/Si(100) are discussed. We establish that epitaxial graphene presents properties similar to those obtained using hexagonal SiC substrates, with the advantage of being compatible with current Si-processing technology.