Band Gap Energy Values Research Articles

Influence of d-d transition electrons and thickness variations on the excited-state optical properties: Nonlinear optical characterization of Cr2O3 thin film

The structural, morphological, linear, and nonlinear optical properties of Cr2O3 thin films with different thicknesses deposited by the thermal deposition, were measured. The structural and morphological parameters of films, determined by XRD, FESEM, and AFM images, are compared to the linear and nonlinear optical characteristics of these media. The bandgap of prepared thin films was obtained from DRS spectra. The electron effective mass (me∗/m0), linear refractive index (n0), optical static, and high frequency dielectric constant (ε0 , ε∞) values were calculated by using the band gap energy values. Increasing the thicknesses of thin films causes to decrease the band gap, an increase RMS, increase the size of nanoparticles and the nonlinear responses of thin films. The high magnitude of n2, and β belonged to the Cr2O3 (300 nm-thickness) in the order of 10−5 cm2/W, and 10−1 cm/W respectively. The fluctuations in nonlinear responses observed at different thicknesses are attributed to d-d transitions and intraband scattering of equilibrium electrons influenced by laser radiation, as indicated by the nonlinearity data. The considerably elevated refractive non-linearity values in the analyzed film materials suggest their potential for practical applications in optoelectronic devices.

Crystal Structure, Optical, Photoluminescence, Raman, and Magnetic properties for Sm-doped Cr-Mg-Bi Ferrites using sensor

The current work,A series of rare earth Sm3+ ion substituted Cr-Mg-Bi ferrites Cr0.7Mg0.2Bi0.1SmxFe2-xO4 (x = 0.00, 0.02, 0.04, and 0.06) have beensynthesized by thesol-gel auto-combustion method. The XRD, FESEM, HRTEM,UV-Vis, FTIR, Raman spectroscopy, Photo Luminesce and Magnetic Properties analysis have been used to investigate structural, morphological, optical, Raman spectroscopy, Photo Luminesce and Magnetic Properties. Every sample contains a single-phase spinel structure, as confirmed by XRD.The substitution of Sm3+ ions is found to increase the lattice parameter from 8.258–8.248Å.A monotone diffraction peak (311) is visible near small angles of degrees (35.33 to 35.13). The Debye-Scherrer equation, the nanoparticles' crystallite size ranges from 35.357–54.778 nm.FE-SEMs reveal a spherical grain that groups and has a porous form, with particles 38.13 to 53.28 nmin size.HR-TEM micrographs illustrate spherical morphology and their average particle size decreases from 55.32 to 65.42 nm. The selected area electron diffraction (SAED) pattern confirms the crystal planes which were revealed from XRD calculations.The spinel structure was confirmed by FTIR spectroscopy, which found 414 cm-1 and 516 cm-1 vibrational band at the octahedral and tetrahedral sites.As the concentration of Sm3+ rises, the direct and indirect band gap energy values determined from UV-Vis show an increase and decrease.The generated NPs' semiconducting nature is confirmed by the strong correlation between the g-value and particle size change.Photoluminescence (PL) investigation shows that all processed samples have four bands.(i) peak centered at 412 nm, which is near-band edge emission and corresponds to the ultraviolet (UV) band,(ii) The violet band has a high-intensity peak at 434 nm,(iii) The blue band is related to a low-intensity, sharp peak located at 466 nm, and (iv) A broad peak at 502 nm with a very low intensity distinguishes the green band.The Raman spectroscopy investigation revealed that the CMBSF nanoparticles had a mixed spinel structure. The magnetic investigation shows that when the Sm content of ferrites increases, saturation magnetization drops from 39.86 to 33.16 emu/g.The sample's coercivity (Hc) increases from 16.06 to 21.90 KOe with Sm substitution.

The Photocatalytic Activity of TiO2 Nanotube Doped Zn for Methylene Blue Degradation

TiO2 nanotube (TiO2-NT) is one of the promising materials for photocatalytic water remediation. TiO2-NT doped Zn (Zn/TiO2-NT) is synthesized from P25 Degussa via one step hydrothermal method. From XRD and UV-DRS analysis, it showed that Zn as a doping material led to decrease band gap energy and decrease the crystallite size. The best results obtained was Zn/TiO2-NT with a crystallite size of 7.14 nm, and band gap energy value of 3.18 eV. Photocatalytic activity of Zn/TiO2-NT was also tested for photocatalytic activity of textile dye (methylene blue) degradation. During the photocatalytic activity for methylene blue degradation, the Zn/TiO2-NT shows higher activity compared to non-doped sample. The non-doped sample shows degradation activity of 87.72%, meanwhile the Zn/TiO2-NT shows degradation activity of 95.88%.

Insights into the structural and optical properties of [formula omitted] substituted [formula omitted]

Y2−xTbxMo4O15(x=0,0.1,0.2,0.3,0.4,0.5,0.6,0.7) were successfully synthesized using citrate nitrate combustion method. The characterization techniques used in the present study involves X-ray Diffraction, Raman and FTIR spectroscopy, transmission electron microscopy, UV-Visible spectroscopy and photoluminescence spectroscopy. Structural analysis concludes that the compound crystallizes in monoclinic phase with space group P21/c as confirmed through Rietveld refinement. Diffuse reflectance spectra show a high absorption in the wavelength range 250 – 400 nm and the band gap energy values are evaluated. Photoluminescence spectra show an intense green emission at 545 nm and luminescence quenching of Y2−xTbxMo4O15 occurs beyond the concentration, x=0.4.The critical distance evaluated using Blasse’s expression is 9.24 Å and dipole-dipole interaction exists between the Tb3+ions which is confirmed through Dexter theory. The optimized nanophosphor has internal and external quantum yields equal to 11.01 % and 9.91 %, respectively, and has a decay time of 0.101 ms. These results strongly suggest that the prepared nanophosphor can be used as a green phosphor in pc-LEDs.

Synthesis, crystal structure, spectroscopic, electronic and vibrational properties of N′-[(E)-3-pyridinylmethylene]nicotinohydrazide trihydrate: Experimental and computational study

N′-[(E)-3-pyridinylmethylene]nicotinohydrazide trihydrate (C12H10N4O·3(H2O)) was synthesized and its structure was determined by single crystal X-ray diffraction method. X-ray analysis showed that the compound crystalized in the triclinic system P-1 with a = 7.1134 (3) Å, b = 10.0208 (4) Å, c = 10.3601 (4) Å, α = 96.386 (3)°, β = 96.995 (3)°, γ = 101.219 (4)°, V = 712.05 (5) Å3 and Z = 2 and exhibits that the title compound (I) consists of N′-[(E)-3-pyridinylmethylene]nicotinohydrazide (II) (C12H10N4O), and three water molecules of crystallization. The two water molecules are attached to the third water molecule through intermolecular two OH…O hydrogen bonds. At the same time, this water molecule is linked to the NH amide group of the hydrazone by an intermolecular NH…O hydrogen bond. Hirshfeld surface (HS) analyses were carried out are to visualise the intermolecular interactions in the crystals of Compound I. The geometric optimization of the titled compound has been carried out by different computational methods such as by Hatree Fock (HF) and Density Functional Theory (DFT) methods with the 6–311++G (d,p) basis set. The vibrational frequency, dipole moment (μ), polarizability (α), hyperpolarizability (β), and electronic properties including the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO–LUMO) of the compound have been calculated at the level of both theories. In the results of crystal analysis and geometry calculations of the compound I, it was observed that intermolecular hydrogen bonds, N2H2A…O3, O3H31…O2 and O3H32…O4, were formed. The energy band gap (Eg = ELUMO-EHOMO) values were also obtained by using ELUMO and EHOMO at the level of both theories. The value of equilibrium (ground state) dipole moment of the studied molecule was calculated to be 8.31 Debye in B3LYP and 7.55 Debye in HF. The calculated hyperpolarizability values at the B3LYP/6–311++G(d,p) of the compound are 2.53 × 10−30 esu and this value corresponds to 6.79 times the hyperpolarizability value of urea.

Computational insight on K2AuBiX6 (X = F, Cl, Br, I) double perovskites to comprehensively investigate mechanical, optoelectronic, and thermoelectric features for green energy applications

In this article, we investigated the structural, elastic, electronic, optical, and thermoelectriccharacteristics of K2AuBiX6 (X = F, Cl, Br, and I) using density functional theory (DFT). To verify the stability of the cubic structure tolerance, octahedral factors, and formation energy have been determined. The mechanical stability has been governed by Born stability criteria. These parameters ensure its strength, ductility, brittleness, and anisotropy. The bandgaps of K2AuBiF6, K2AuBiCl6, K2AuBiBr6, and K2AuBiI6 have been determined using the TB-mBJ potential. The calculated values of energy band gaps are 2.88, 2.02, 1.38, and 0.95 eV, respectively. These materials exhibit a broad absorption in visible regions, a refractive index range of around 1–3, and low light scattering, which makes them ideal for optoelectronic applications. In addition, the figure of merit (ZT) values for these compounds at room temperature are 0.76, 0.78, 0.77, and 0.80, ensuring their suitability for use in thermal devices.

New Silver(I) Complexes as Achromatic Sensitizers in Solar Cell Applications

ABSTRACTThe design, synthesis, and spectroscopic characterization of [Ag(P(o‐C6H4OCH3)3)(NO3)]2 (1) and [Ag(P(o‐C6H4OCH3)3)2][NO3] (2) were conducted to investigate the efficiency of the fabricated solar cell devices. The slow evaporation technique proved effective in growing the colorless crystals of the silver(I) complexes. Spectroscopic analyses including Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and ultraviolet–visible (UV–Vis) studies were carried out to elucidate the chemical structure and absorption properties of the compounds. The chemical composition and existence of intermolecular interactions in 1 and 2 were disclosed via the single‐crystal x‐ray diffraction method. The side‐to‐side arrangement of molecules in 1 and 2 was evident from the crystal packing analysis, in which the molecules in both compounds were linked together by C–H···O and C–H···π contacts. The silver(I) complexes exhibited maximum absorption wavelength (287–288 nm) within the ultraviolet region, where both compounds had comparable high energy band gap values ranging from 4.15 to 4.16 eV. Moreover, both compounds possess appropriate HOMO–LUMO energy levels that facilitate effective electron injection and dye regeneration processes in dye‐sensitized solar cell (DSSC) applications. Photophysical characterization techniques, field‐emission scanning electron microscopy (FESEM), and energy‐dispersive x‐ray (EDX) spectroscopy studies were employed to assess the morphological characteristics and elemental composition of the silver(I) complexes on TiO2. Compound 2 exceeded 1 in terms of solar cell efficiency, 2 (η = 3.34%) > 1 (η = 0.66%) due to the complex being in ionic form and composed of the mononuclear [Ag(P(o‐C6H4OCH3)3)2]+ cation [NO3]− anion.

Sol gel fabrication of CeO2/SnO2 nanocomposite films for habilitation in optoelectronic and sensing properties

This study investigated the synthesis and characterization of CeO2/SnO2 composite powders and films by varying CeO2 concentration ranging from 2 to 10 mol%. The sol-gel process was utilized to create composites. X-ray diffraction demonstrated that the resulting CeO2/SnO2 powders were polycrystalline, whereas the composite films had amorphous structures. The morphology of the produced samples was studied with SEM and TEM. Also the specific surface area was measured using the Brunauer-Emmett-Teller (BET) technique and the optical characteristics were assessed using a UV–Vis spectrophotometer. The absorption coefficients, energy gaps, and refractive indices of the composite films were determined. Direct and indirect energy gaps were from 3.71 to 3.27 eV and 2.70 to 2.26 eV, respectively. The refractive index increases from 1.61 to 1.7 as the CeO2 concentration increases. The variation in the energy band gap and refractive index values indicate that CeO2/SnO2 nanocomposite films are a viable composite film for optoelectronic devices. The investigated films have electrical conductivity values ranging from 10−2 to 10−8 Ω−1 cm−1. The gas sensing test was studied using different gases as liquid petroleum gas (LPG), carbon monoxide (CO), and Hydrogen sulfide (H2S). CeO2/SnO2 films demonstrated the highest sensitivity for hydrogen sulfide (H2S), with a sensitivity of 0.988 % and a response time of 40 s.

Exploring the Multifunctional aspects of SrBi2-X(CoFe2O4)XNb2O9 Nanocomposite Materials Emphasizing the Structural, Elastic, and Optical Properties

Nanocomposites of SrBi(2-X)(CF)XNb2O9 (SBNCF) (CF=CoFe2O4 for X = 0.0 to 0.5 with a step increment of 0.1) were synthesized using the hydrothermal method and characterized for their structural, morphological, elastic, and optical properties. The incorporation of CF into SrBi2Nb2O9 (SBN) resulted in hybrid composites with tailored properties. X-ray Diffraction (XRD) with Rietveld refinement analysis confirmed the formation of orthorhombic SBN and spinel CF phases. Field Emission Gun Scanning Electron Microscopy (FEG-SEM) revealed that SBN exhibits a plate-like morphology, with the incorporation of CF into the SBN matrix resulting in both plate-like and octahedral-shaped grains. The Brunauer–Emmett–Teller (BET) method was used to determine the pore radius and surface area, both of which were found to have increased, indicating an enhancement in photocatalytic performance. The presence of the constituent elements in the prepared compositions was confirmed by Energy Dispersive Spectroscopy (EDS). Fourier Transform Infrared Spectroscopy (FTIR) spectra were used to determine elastic properties, suggesting potential applications in electronic noise filtering. From Diffuse Reflectance Spectroscopy (DRS), a recognizable semiconducting behavior and band gap bowing were noticed in SBNCF nanocomposites on the obtained energy band gap values (2.20 eV - 1.56 eV) compared to the SBN host matrix (3.16 eV). The materials exhibited strong emission peaks at 470 nm, 528 nm, 584 nm, and 703 nm upon the excitation of 425 nm light using Photoluminescence (PL) spectroscopy. The white emission was predominant at room temperature in all the produced samples and the corresponding color temperature values range from 5865.93 K to 7599.05 K from the CIE diagram. The SBNCF materials are promising candidates in photocatalytic reactions and white light-emitting diodes (w-LEDs) based on their enhanced optical properties.

Structural, optical, and dielectric characteristics of Fe doped ZrO2 nanoparticles for multifunctional applications

Combustion synthesis was used to synthesise the undoped and Fe3+ ions incorporated ZrO2 nanostructures using Tamarind indica extract. The synthesised ZrO2 nanoparticles with a tetragonal phase and a particle size <45 nm were found by structural investigation. Fe doping causes the optical band gap of ZrO2 nanostructures to decrease. Due to the hybridization of the host and dopant orbitals, the energy band gap value of the resulting nanoparticles considerably become smaller (from 5.35 eV to 4.18 eV) towards the visible range. By studying PL measurements of the synthesised samples, it is confirmed that the presence of oxygen vacancies was observed. The size and phase purity of the nanoparticles are responsible for the intriguingly high dielectric constant increase of up to 9.7 × 104 with very little loss following the integration of Fe into the ZrO2 medium. The high value of dielectric constant and uniform nanoparticles produced have applications in high-frequency devices and technologies such as spintronics as multifunctional applications.

Atomic layer deposition, mechanical, wear resistance, and optical properties of (Cr1-xAlx)2O3 films on Si (100)

This study presents the comparison of microstructure, mechanical, tribological, and optical properties of the ternary chromium-aluminum oxide films ((Cr1-xAlx)2O3) with binary Cr2O3 and Al2O3 films, deposited by atomic layer deposition at 275 °C. The atomic growth per cycle of the Al atoms increased from 3.1 to 8.5 atoms/nm2 on chromium oxide film. The Al2O3 films were X-ray amorphous. The Cr2O3 films contained crystallites of the eskolaite phase. Nano-size (diameter from 3 to 5 nm) crystallites with cubic symmetry and matching with that of cubic γ-Al2O3 or η-Al2O3 phases were observed in (Cr1-xAlx)2O3 films. The ternary film with Al/(Al + Cr) of 0.40 showed the highest hardness (18.4 GPa) and elastic modulus (169.4 GPa), whereas the wear rate of this film decreased by ∼80 % compared with Cr2O3 films. Optical band gap energy values corresponding to the indirect transition model decreased from 2.93 eV for the Cr2O3 film to 2.58 eV for the Cr-Al-O films.

Ligand-free Ni-Cu bimetallic nanocatalyst: Laser synthesis, characterization and its high performance for borohydride assisted catalytic reduction of 4-nitrophenol

In the present work, nickel and copper bimetallic nanoparticles with three different concentration ratios of 70:30, 50:50, and 30:70 were synthesized by laser ablation of Ni and Cu in deionized water. The suitability of Ni-Cu bimetallics as nanocatalysts was investigated in the catalytic reduction of pollutant 4-nitrophenol. The nanocatalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV–Vis) spectroscopy. The morphology using SEM and TEM indicated that Cu had an elongated or flake-like structure, whereas Ni had a quasi-spherical structure. XPS investigation has been performed to study the elemental composition and chemical states near-surface regions of the generated Ni-Cu bimetallic nanoparticles. XRD and XPS confirm high oxidation of Cu to CuO with approximately no residual Cu metal. However, the XRD patterns did not show complete Ni oxidation to NiO, confirming the presence of a Ni dopant part in the Ni-Cu samples. The behavior of the photoelectron peaks in the XPS spectra suggested that the Ni-Cu nanocomposites exhibited surface charge transfer. Pulsed laser ablation developed ligand-free Ni-Cu nanoparticles, which affected the structure and catalytic properties. The nanocatalyst for 50:50 of Ni and Cu had the highest rate constant, corresponding to the shortest time required to achieve 100 % conversion/reduction of the pollutant dye. The apparent synergistic effect between Ni and Cu is clearly dictated by the amount of Cu embedded in the nanocomposites, with this becoming a key factor in lowering the band gap energy values. Overall, the surface charge transfer rate can enhance the catalytic performance by tuning the Ni and Cu concentrations.

Annealing effects on 100 keV silicon negative ions implanted SiO2 thin films

SiO2 thin film of thickness 300 nm grown on p-type silicon substrate was implanted with 100 keV silicon negative ions for the fluences of 1 × 1016, 5 × 1016, and 1 × 1017 ions cm−2. The implanted samples were investigated using an energy-dispersive X-ray (EDX) spectroscopic technique, and the samples were annealed at a temperature of 900 oC under N2 ambient. Ultraviolet–visible near infrared (UV-Vis-NIR) spectroscopy has been used to investigate the implanted SiO2 thin film samples before and after thermal annealing. EDX results revealed an increase in the atomic percentage and weight percentage of silicon ions as compared to oxygen ions in SiO2 thin film. This may be due to the increase in the concentration of silicon ions with the increase of implanted ion fluences within the SiO2 thin film. UV-Vis-NIR studies showed higher transmittance for thermally annealed samples as compared to non-annealed samples. This may be attributed to the creation of a new SiOx phase in the SiO2 matrix at higher temperatures. UV-Vis-NIR studies also exhibited an increase in the energy band gap value after thermal annealing. This effect may be related to the formation of silicon nanoclusters in SiO2 thin film.

Photodegradation of Methylene Blue Dye Using BiVO₄/g-C₃N₄ Composites under Visible Light Irradiation

This study evaluates the degradation of methylene blue through photocatalysis using BiVO4/g-C3N4 material with the help of visible light. Material characterization was conducted using X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse reflectance spectroscopy data. The characterization results show that the crystal structure of BiVO4/g-C3N4 is a heterojunction between monoclinic BiVO4 and hexagonal g-C3N4, with a crystal size of about 10.16 nm and a band gap energy value of about 2.16 eV. The morphology formed is a combination of sheet and rod-like. This study optimized the photocatalytic activity of the composite by analyzing the variation of g-C3N4 concentration, degradation time, and methylene blue pH. The results show that the BiVO4/g-C3N4 sample has optimal photocatalytic and adsorption properties in sample B (1:3) with pH 7 and a degradation time of 150 minutes. Under these conditions, the BiVO4/g-C3N4 composite successfully degraded methylene blue by 94.14%. The rate kinetics of the photocatalytic reaction followed first order, with *OH species playing the most role in the degradation mechanism. These findings highlight the potential of BiVO4/g-C3N4 as an effective photocatalyst material for organic pollutant degradation applications, offering a sustainable solution for wastewater treatment.

Scaling up features of photocatalytic degradation and radiation shielding of multicomponent Cr–Co–Zn nanoferrites

Optical, photocatalytic activity, and radiation shielding studies were conducted on CrxCo0.8Zn0.2Fe2-xO4 (0.0 ≤ x ≤ 0.1, Δx = 0.02) nanoferrites for water treatment and radiation shielding applications. The optical absorption analysis revealed that the optical band gap energy values range from 1.864 to 1.803 eV as assessed through Tauc plots. Further analysis of photocatalytic degradation showed that the Cr0.06Co0.8Zn0.2Fe1.94O4 sample exhibited superior methylene blue (MB) dye removal compared to other samples, with an efficiency of 96.74% in 60 min. Additionally, the present nanoferrites exhibited excellent stability in photocatalytic degradation over multiple cycles. The study also investigated the linear attenuation coefficient (LAC) of the current ferrite nanoparticles, demonstrating increased LAC values with higher Cr content, while the half value layer (HVL) diminished with further Cr concentration. The HVL values indicated the potential efficacy of our nanoferrites as radiation shields when compared to standard radiation shielding materials. Overall, this research suggests a new direction for optimizing spinel nanomaterials for applications in water treatment and radiation shielding.

DFT electronic structure investigation of chromium ion-implanted cupric oxide thin films dedicated for photovoltaic absorber layers

This study explores the enhancement of cupric oxide (CuO) thin films for photovoltaic applications through chromium doping and subsequent annealing. Thin films of CuO were deposited on silicon and glass substrates using reactive magnetron sputtering. Chromium was introduced via ion implantation, and samples were annealed to restore the crystal structure. The optical and structural properties of the films were characterized using X-ray diffraction, spectrophotometry, and spectroscopic ellipsometry. Results indicated that implantation reduced the absorbance and conductivity of the films, while annealing effectively restored these properties. Sample implanted with 10 keV energy and 1 × 1014 cm−2 dose of Cr ions, after annealing had sheet resistance of 1.1 × 106 Ω/sq compared to 1.7 × 106 Ω/sq for non implanted and annealed CuO. Study of crystalline structure confirmed the importance of annealing as it reduced the stress present in the material after deposition and implantation. Density Functional Theory (DFT) calculations were performed to investigate the electronic structure and optical properties of CuO with varying levels of chromium doping. Calculations revealed an energy gap of 1.8 eV for undoped CuO, with significant changes in optical absorption for doped samples. Energy band gap determined using absorbance measurement and Tauc plot method had value of 1.10 eV for as deposited CuO. Samples after implantation and annealing had energy band gap value increased to about 1.20 eV. The study demonstrates that chromium doping and subsequent annealing can enhance the optical and electronic properties of CuO thin films, making them more efficient for photovoltaic applications.

Biosynthesis of silver nanoparticles using green tea aqueous leaf extract and their biological and chemotherapeutic activity

Green tea leaf extract-mediated silver nanoparticles (GT-AgNPs) were synthesized and characterized for their biological and chemotherapeutic activity. The synthesis process involved the reduction of silver ions by green tea leaf extract (GTLE), resulting in the formation of GT-AgNPs. Characterization techniques including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis were employed to study the physicochemical properties of GT-AgNPs. The GT-AgNPs exhibited a characteristic color change and a noticeable shift in the surface plasma resonance (SPR) absorption peak at 458 nm, confirming their successful formation of nanoparticles. XRD analysis indicated a cubic structure with a crystallite size of 9 ± 1 nm. Both SEM and TEM images revealed that the spherical shape and size of the synthesized nanoparticles. The SEM analysis confirmed that the average grain size of GT-AgNPs is 20.27 ± 1 nm, while the TEM analysis determined the average particle size of 9 ± 0.025. GT-AgNPs have a negative zeta potential of -19.7 mV indicating a hydrodynamic diameter of 140.90 nm with a polydispersity index (PDI) of 25.8 %. XPS confirmed the oxidation state of Ag0/+1 in GT-AgNPs. The energy band gap (Eg) value of GT-AgNPs is 3.38 eV, indicating semiconducting properties, while fluorescence activity was observed at 506.17 nm. CT-DNA and BSA protein binding studies demonstrated the formation of CT-DNA-GT-AgNPs and BSA-GT-AgNPs complexes with binding constants of 1.366×1010 M−1 and 6.77×109 M−1, respectively. GT-AgNPs exhibited exceptional anti-oxidant activity by effectively scavenging stable 2, 2ʹ - diphenyl-1-picryl hydroxyl (DPPH) radicals. Cytotoxicity assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) demonstrate moderate activity against KB3 and AGS cancer cells while showing no detectable cytotoxicity in Caco-2 cells. This indicates a safe therapeutic window for human eukaryotic cells.

Structural studies, DFT computational analysis and inhibitory potential of (E)-N'-(2-bromophenyl)-N-(2,6-diisopropylphenyl)formamidine against CDK1 and CDK2

Compound (E)-N'-(2-bromophenyl)-N-(2,6-diisopropylphenyl)formamidine (BDF) was synthesized and elucidated by FT-IR, UV–Visible, 13C & 1H -NMR, spectroscopy as well as mass spectrometry techniques. The crystal structure of BDF was affirmed using single crystal X-ray diffraction technique. The molecular conformation of BDF is such that the dihedral angle between its phenyl rings is 57.62(10)° while the two rings were orientated with the formamidine functional group in a synclinical form. The intermolecular N—H…N together with C—H…π hydrogen bonding patterns exist in the crystal packing of BDF and Hirshfeld surface (HS) analysis was carried out to study their significance in the formation of one-dimensional supramolecular architectures within the crystal lattice of BDF. The geometry parameters of BDF were investigated using various basis sets and the B3LYP/6–311++G(d,p)[cc-PVTZ-PP] level of theory gave the closest match to the experimental values. The calculated ELUMO, EHOMO and energy band gap (∆E) values for BDF are -0.85 eV, -5.97 eV, and 5.12 eV respectively. The inhibitory potential of BDF against cyclin-dependent kinase 1 (CDK1) and 2 (CDK2) were investigated through molecular docking, molecular dynamics (MD) simulations as well as post-MD which include Root Mean Square Fluctuation (RMSF), Root of Gyration (RoG) and Root Mean Square Deviation (RMSD). The molecular docking studies revealed that BDF has better docking scores than known inhibitor (roscovitine) of CDK1 and CDK2. Outcomes of the MD simulation unveiled that BDF exhibited good free binding energies against the two proteins but did not outshine the ones for roscovitine. However, further optimization of BDF could enhance its binding energies against CDK1 and CDK2. Pharmacokinetics and pharmacological approximation revealed that BDF did not violate the Lipinski’ rule and this indicates its tendency to be orally bioavailable and to a lesser extent toxic.

Promising CO2 gas sensor application of zinc oxide nanomaterials fabricated via HVPG technique

Highly effective gas sensors for detecting a range of hazardous and toxic gases were successfully applied in the present study using Zinc oxide (ZnO) nanomaterials. In this work, the horizontal vapor phase growth (HVPG) technique was perfectly capable of the synthesis of zinc oxide (ZnO) nanomaterials. The effect of the growth time with different dwell times was discussed by comparing the SEM-EDX analysis and photoluminescence characterization of the samples. Magnetic field (AMF) was also incorporated to determine the effect of AMF on the synthesis of ZnO nanomaterials. The results showed that the ZnO nanorods and root-like shapes are formed with more than 5 μm length and a few nm diameters. The optimum parameter showed the sensors are shiner than the less effective sensor when applied. The introduction of an external magnetic field led to a reduced energy band gap by a maximum of 15 %. The non-AMF band gap energy value is observed to be between 3.51 and 3.58 eV, while the value obtained using AMF is found to be between 2.94 and 3.22 eV. During the CO2 gas sensor test, AMF ZnO nanomaterial samples exhibited higher voltage and gradient compared to non-AMF samples.

Shielding against erosion: Exploring the effectiveness of pre-erosion surface corrosion inhibitors

This study investigates the corrosion inhibition effect and adsorption process of two imidazoline corrosion inhibitors, HEIE and TDEI, on pre-eroded X65 steel surfaces. Analysis of weight loss and electrochemical measurements suggests that the irregular structure of pre-eroded surfaces may impede the uniform adsorption of corrosion inhibitors, resulting in reduced effectiveness pre-erosion. Particularly, at a 30° angle of pre-erosion, corrosion inhibition efficacy is observed to be at its lowest. The corrosion inhibition rates of HEIE and TDEI on X65 steel surfaces are found to be 11.9 % lower under pre-eroded conditions at a 30° angle compared to non-eroded surfaces at the same angle. Molecular dynamics (MD) simulations support these findings, indicating that TDEI exhibits lower energy bandgap values and more negative adsorption energies (Eads) compared to HEIE, aligning with experimental results. Moreover, TDEI demonstrates a smaller diffusion coefficient for corrosive agents than HEIE, suggesting stronger adsorption efficiency and a more pronounced protective effect. Study of the corrosion inhibition effect on pre-eroded surfaces provides new ideas and methods for improving protective measures.