International Journal of Nano Dimension
Volume:16 Issue: 1, Winter 2025

The electronic,thermoelectric and optical properties of bulk and nanolayers chalcogenides, specifically XTe (X= Si, Ge, Sn, and Pb) and PbY (Y = O, S, Se, and Te), have been investigated using density functional theory(DFT) with the GGA-PBE functional and semiclassical Boltzmann theory via Quantum ESPRESSO andBoltzTraP codes. The results of the electronic band structure analysis indicate that compounds such as PbO,PbS, PbSe, PbTe and GeTe exhibit direct band gaps, making them suitable for semiconductor applications.On the other hand, SiTe and SnTe compounds exhibit metallic behavior. Also, the GeTe bulk was convertedfrom semiconducting to conducting in the nanolayer structure. The thermoelectric properties of these bulkand nanolayerschalcogenides, including electrical conductivity, electronic thermal conductivity, and Seebeckcoefficient, have been calculated. It was observed that the Seebeck coefficient decreases with increasingtemperature in all semiconductor samples. Moreover, the thermal and electrical conductivity coefficientsincrease with the increase in chemical potential, transferring it to the electrons in the conduction layer.Based on the findings, it can be concluded that PbTe shows promising potential as a candidate materialfor thermoelectric devices. Seebeck coefficient in PbO, PbS, and PbSe nanolayers increased compared tothe bulk structure. The optical properties, including the real and imaginary parts of the dielectric function,absorption, and reflectivity as a function of energy, have also been calculated. The absorption edges ofthe bulk chalcogenides extend into the visible spectrum due to their suitable bandgap values. Additionally,these materials exhibit non-transparency in certain regions of the electromagnetic spectrum, making themsuitable for use as absorbent materials. Among the chalcogenides studied, PbS shows promising potential foroptoelectric industries due to its low refractive index and high optical gap. Also, the decrease in the refractiveindex of the nanolayers compared to the bulk shows more optical absorption in them. Additionally, amongbulks compounds, PbTe shows promising potential for thermoelectric applications, while among nanolayers,PbO is the most suitable material.

The rising demand for environmentally friendly technologies has spurred research into nanoparticle productionmethods utilizing biological agents. This study investigates the synthesis of silver nanoparticles (AgNPs)using extracts fromBrugmansia suaveolensleaves and flowers as reducing agents. The nanoparticleswere thoroughly characterized using DPPH assay, UV-visible spectroscopy, X-ray diffractometer (XRD),Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Both leaf andflower extracts were assessed for their antibacterial, antifungal, and anti-inflammatory properties, confirmingthe presence of bioactive compounds such as amines, carbohydrates, alkaloids, glycosides, saponins, andflavonoids. The synthesized AgNPs exhibited crystalline structures with average sizes of 102.7 nm (flowerextract) and 75.2 nm (leaf extract), demonstrating robust antioxidant activities and effective inhibition againstpathogens includingStaphylococcus aureus,Bacillus subtilis,Escherichia coli,Xanthomonas campestris, andAspergillus niger. These AgNPs were incorporated into gel formulations, evaluated for physical characteristicsandin vitrodiffusion properties. Notably, batch F6 showed exceptional skin penetration, with 84.96% ofnanoparticles penetrating goat skin. Overall, these findings highlight the potential of AgNPs-loaded gelformulations as promising therapeutic options for chronic injuries and mild burns, warranting furtherin vivostudies to assess safety and efficacy.

Researchers are currently interested in the biosynthesis of nanoparticles (NPs) due to their importanceto develop cost-efficient, eco-friendly, and effective synthesis methods. The primary aim of this currentinvestigation is to produce nickel nanoparticles (NiNPs) by synthesising them from the defensive secretionacquired from the beetleLuprops tristis(L. tristis). The resulting nickel nanoparticles, referred to as LNiNPs,are recognized as being biosynthesized. The synthesis of LNiNPs from pure metal was verified by UV-Visspectroscopy, and FTIR analysis indicates the functional groups attached to the nanoparticles that serve asthe reducing and capping agents. Analysis using cyclic voltammetry ensures the reducing property of thephenolic compounds present in the defensive gland extract of the beetle. Scanning electron microscopy (SEM)and transmission electron microscopy (TEM) revealed the spherical shape of biosynthesized LNiNPs withan average size of 18 nm, while dynamic light scattering (DLS) analysis indicated a hydrodynamic size ofapproximately 48 nm. Zeta potential analyses of the nanoparticles show that biosynthesized nanoparticlesare more stable. Non enzymatic glucose sensing study by differential pulse voltammetry shows a lowerdetection limit of 1.31μM. The disc diffusion antibacterial assay of LNiNPs demonstrated a dose-dependentinhibition of bacterial growth, with antimicrobial activity increasing proportionally to the concentration ofLNiNPs. Chromosomal aberration experiments using LNiNPs revealed chromosomal aberrations inAlliumsepaL. DPPH assay supported strong antioxidant properties of LNiNPs at higher doses. Additionally, itshows dose-dependent cytotoxicity against Dalton’s lymphoma ascites cells (DLA cells). Despite the fact thatL. tristisannoys people, its secretion can be used to bio synthesise nickel nanoparticles, which offer additionalbenefits such as antibacterial, antioxidant, and anticancer, glucose sensing properties.

The current investigation emphasizes the Aluminum oxide in water nanoparticles’ effect on double-diffusivemixed convection flow in lid-driven enclosure numerically. The main purpose of the investigation is theassessment of the changes in heat and transfer, due to variations of the dimensionless parameters of theRichardson number that covers the range of 0.01 and 100, the Lewis number that changes from 0.1 to 10,also 0 to 5 are related to the changes of the buoyancy ratio and the nanoparticles volume fraction is fallenin the range of 0 to 0.06 and the location displacement of the source from the highest to lowest in the leftwall. The control volume method, SIMPLER algorithm, and a hybrid discretization method are applied to thegoverning equations. The fluctuations of the mean Nusselt number as well as the mean Sherwood numbers viathe variation of the mentioned dimensionless numbers are illustrated. The results indicate that heat transfer isenhanced with increasing nanoparticle concentration, while mass transfer is subsided. Moreover, the rate ofboth heat and mass transfer is amplified by up to 25% as the buoyancy ratio increases from 0 to 5. However,the Richarson number increment makes a decrement in both.

Nanotechnology has a broad spectrum in various fields such as chemistry, biology, physics, material sciences,and engineering. Due to the unique features of nanoparticles, it has a wide range of biological applicationslike Nanomedicine, biosensors, agriculture, and industry. The current study uses an environmentally friendlymethod of green synthesis of copper nanoparticles usingClitoria ternatealeaf extract. By using sophisticatedinstruments like UV-visible spectroscopy, FTIR, SEM, and zeta potential, the copper nanoparticles werecharacterized. The FTIR spectrum analyzed the functional groups in leaf broth. Scanning Electron Microscope(SEM) confirmed the size and morphology (spherical) of copper nanoparticles. The charge and size of CuNPswere confirmed by Zeta potential. The copper nanoparticles exhibited good antibacterial activity on Gram-positive (Bacillus subtilis) and Gram-negative (E. coli) bacteria and antifungal properties on fungal strainA.niger. The free radical scavenging activities of copper nanoparticles were studied with DPPH and HydrogenPeroxide in vitro assay methods. The biogenic CuNPs act as good antioxidants and larvicidal agents. Theantiviral activity of CuNPs was investigated onSesbania mosaic virus(SeMV), which infectsSesbaniaplants.The green synthesized CuNPs act as good antiviral agents for decreasing the mosaic symptoms caused by theSesbania Mosaic Virusin theSesbaniaplant, and it indicates the antiviral efficacy of copper nanoparticles inthe Agricultural sector.

Pristine and Nickel doped Copper Oxide (CuO) nanocomposite were synthesized using Centratherum Puncta-tum leaf extract. The structural characterization is performed employing XRD, SEM, and EDAX. Pure CopperOxide nanoparticles (CuO Nps) exhibit leaf-like morphology, but Nickel-doped Copper Oxide nanocompos-ites exhibit a mixture of rod, spherical and hexagonal morphology. Owing to the XRD data, the resultingparticles for NiO NPs, CuO NPs, and Ni-doped CuO nanocomposite comprised crystallite sizes of 35 nm,41 nm, and 37 nm, respectively. The optical properties and functional group of the materials are analyzedutilizing UV-Vis and FTIR. The rise in the measured optical band gap values was seen by the blue shift notedin the UV-vis study subsequent to nickel doping. The existence of different functional groups in samples isverified by FT-IR characterization. The electrochemical analysis is studied by cyclic voltammetry. It exhibitsan elevated specific capacitance value of 314 F/g for Ni doped copper oxide nanocomposite. The antibacterialactivity studies reveal that the Ni-doped nanocomposite is active against gram-negative bacteria over andabove the gram-positive bacterial species.

In this work ZnFe2O4nanoparticles (NPs) were synthesized via green method using shoots ofCamelliasinensis(C. sinensis). The crystalline nature of ZnFe2O4NPs (CS-ZnFe2O4NPs) was confirmed by X-raydiffraction (XRD) and selected area electron diffraction (SAED) study. Further characterizations were doneusing UV-Vis spectroscopy, FTIR spectroscopy, SEM-EDX, TEM, XPS, and VSM. The size of synthesizedNPs was calculated to be 14.4 nm which presented spherical morphology along with some irregular shapedparticles. The synthesized nanoparticles showed excellent catalytic activity towards degradation of a widelyused pesticide, Thiamethoxam under solar radiation. Thiamethoxam got 89% degraded within 60 minutesof experimental time. This work is carried out for the first time where zinc ferrite nanoparticles have beensynthesized usingC. sinensisfollowed by the application towards Thiamethoxam (THIA) degradation.

:A quick approach to extract and monitor trace amount of Fe(III) and Zn(II) ions by nanoporous silica (SBA-15)functionalized with phenyl isothiocyanate groups and inductively coupled plasma optical emission spectrom-etry (ICP-OES) is presented. Phenyl isothiocyanate functionalized SBA-15 was constructed based on theprocess defined in previous studies and was used as a novel adsorbent for Fe(III) and Zn(II) preconcentration.We examined the optimal adsorbent amount, stirring time, pH and the smallest quantity of acid needed forstripping and the volume required to achieve breakthrough. Zn(II) and Fe(III) in 25 mL solution of 4 mg/Lwere completely extracted at pH = 6 after shaking for 5 min. The highest adsorbent capacity was1237±1.0μg and962±1.4μg of Fe(III) and Zn(II) ions/mg functionalized SBA-15. The method’s preconcentrationfactor was determined as 20. The approach detection limit was 3.2 and 5.7μg/L for Zn(II) and Fe(III). Phenylisothiocyanate-modified SBA-15 was effectively used as a novel solid extractant to concentrate Zn(II) andFe(III) ions simultaneously from water samples.