The green pathway is considered an alternative to the conventional chemical method for synthesising metal nanoparticles. This study demonstrates a facile biogenic synthesis of bismuth nanoparticles (BiNPs) using Piper chaba stem extract as a reducing and capping source. Synthesised BiNPs were characterised using various analytical tools. XRD analysis confirmed the formation of crystalline BiNPs. FTIR analysis identified the functional groups from P. chaba extract involved in the BiNPs stabilisation process, while zeta potential measurement confirmed their stabilisation. The TEM image revealed spherical nanoparticles with an average size of 15 nm. EDX analysis showed bismuth as the dominant element, with traces of carbon and oxygen from organic moieties on the surface of BiNPs. TGA also supports the existence of phytochemicals with BiNPs and good thermal stability up to 800 degrees C, supporting its suitability for high-temperature applications. The catalytic activity of BiNPs in reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with NaBH4 showed rapid conversion of 4-NP to 4-AP within 22 min, with a rate constant of 6.77 s(-1) g(-1), demonstrating the excellent catalytic efficiency of BiNPs. Following green chemistry principles, these findings suggest that P. chaba-mediated BiNPs can serve as highly effective nanocatalysts for various chemical transformations and environmental purification processes.
Yttrium-substituted Co0.5Cu0.5YxFe2-xO4 ferrites (x = 0.00, 0.03, 0.06, 0.09) were synthesized via conventional solid-state route and sintered at 800 °C to explore their structural, optical, and magneto-dielectric characteristics. X-ray diffraction confirmed a predominant cubic spinel phase, with orthoferrite secondary phases appearing at higher Y contents. The lattice parameter initially expanded to 8.376 Å (x = 0.03) but decreased systematically to 8.356 Å, lower than the undoped value (8.362 Å) at x = 0.09. SEM revealed well-crystallized grains with reduced grain size from 180.25 μm to 108.76 μm, corroborated by EDS showing stoichiometric composition. Optical studies indicated a widening band gap from 3,80 eV to 5.05 eV with Y incorporation. Dielectric measurements showed a significant drop in dielectric constant (1305.01 → 183.41) and loss tangent (2.22 → 1.24) with doping and frequency, consistent with interfacial polarization. Electric modulus analysis revealed an increased Mɛ′ value (0.044 at x = 0.09) and relaxation peaks in Mɛ″ shifting from 3.28 kHz to 11 kHz, indicating grain boundary relaxation. Nyquist impedance spectra exhibited dual arcs associated with grain (Mɛ″ ≈ 0.008 at x = 0.09) and grain boundary (Mɛ″ ≈ 0.0045 at x = 0.09) contributions. Magnetic characterization showed imaginary permeability ranging from 2479.8 to 3022 and energy loss factors between 298 and 340 at low frequencies, both declining rapidly beyond 3 kHz. Compressed magnetic Nyquist arcs with increasing Y confirmed enhanced AC conductivity, with x = 0.09 delivering the smallest arc and superior performance. Notably, this composition achieved impedance matching of 0.68 at 0.6 MHz, indicating promising electromagnetic behavior in the MHz range, with potential applicability in high-frequency devices pending further investigation in the GHz regime.
Water contamination is one of the most serious health problems worldwide nowadays. Untreated discharge of synthetic organic dyes into water supplies can have detrimental effects on the environment. These dyes make up the majority of water contaminants. Therefore, the purpose of this study is to use spinel ferrite, a novel and highly advanced catalytic material, to address this problem. Using the chemical coprecipitation method, a gadolinium-doped spinel ferrite complex Cu0.3Ni0.7GdXFe2-XO4 (x = 0.0, 0.25, 0.5, 0.75) has been created with this goal in mind. Phase formation of the substance was confirmed by XRD analysis. The sizes of the crystallites were found to be 24.07, 23.02, 24.03, and 22.02 nm for x = 0.0, 0.25, 0.5, and 0.75, respectively. The surface examination was carried out by FE-SEM. The synthesized nanoparticle broke down the complex structure of ammonium purpurate dye. Approximately 92
Effective treatment of organic dye-contaminated water is of great importance, and graphene derivatives are excellent examples for decontamination due to their exceptional properties, especially the large surface area and chemical stability. The present study focused on the utilization of orange peel extract-assisted reduced graphene oxide (rGO) as a promising adsorbent for the removal of methylene blue (MB) dye. To synthesize rGO from graphene oxide (GO), orange peel extract serves as a reducing agent, offering a cost-effective, renewable, and environmentally friendly alternative. The green-synthesized rGO was characterized using UV-vis, FTIR, EDX spectroscopy, TG analysis, XRD, and TEM. These comprehensive analyses confirmed the effective reduction of GO and the successful formation of few-layered, exfoliated rGO nanosheets. The adsorption performance of the synthesized rGO for the removal of MB was assessed. The adsorption kinetics of MB on rGO can be best described by the pseudo-second-order kinetics model and the Langmuir model, which indicates that a chemisorption process governs the adsorption through a monolayer adsorption on the homogeneous surface of rGO. The maximum adsorption capacity is 82 mg/g, and the removal efficiency is 80%, which testifies to the suitability of the synthesized rGO as a promising adsorbent material.
We present a hybrid-octagonal-photonic-crystal-fiber (HOPCF)-based glucose sensor, in which the core is circular and cladding is octagonal including elliptical holes that are filled with glucose as a sensing material. The proposed HOPCF-based glucose sensor is analyzed applying the finite element techniques with a PML (perfectly-matched-layer) boundary from 1.2 μ m to 1.8 μ m wavelength range. The sensor performance parameters depend on the glucose concentration, operating wavelength, temperature of the sensing element, and the radius of the core, respectively. We find that when the temperature of the sensing element or radius of the core increases, the key sensor performance parameter, especially the sensitivity, decreases. Moreover, the proposed sensor shows 81.81 × 10 ^-8 dB/m of confinement loss, 2.44 × 10 ^-2 birefringence, 13.69 μ m ^2 effective area, and 7.798 w ^-1 km ^-1 non-linear co-efficient at 1.55 μ m of wavelength, respectively. Our proposed HOPCF-based glucose sensor offers a comparatively high sensitivity, moderate birefringence, and low confinement loss while these sensor performance parameters are glucose concentration, temperature, wavelength, and core radius dependent.
