Band Gap Energy Research Articles

Structural Optimization of Chalcogenide Thin Films for Enhancing the Threshold Switching Performance.

This study conducts a comprehensive investigation into the physical properties of germanium telluride (GeTe, GT) thin films and their associated electronic devices to establish fundamental relationships that are essential for achieving reliable threshold switching (TS) characteristics. Chemical composition variations in GT thin films significantly influence their crystallinity, atomic vibration modes, chemical binding status, bandgap, and distribution of electronic traps. The increase in the tellurium (Te) content results in elevated Urbach energy, subsequently reducing the effective bandgap energy. Excluding GT8, trap energy increases proportionally with increasing Te content. Correlating electrical properties with physical characteristics reveals key conditions necessary for stable TS behavior: maintaining amorphous crystallinity, optimizing the chemical composition of the GT layer, and ensuring an appropriate bandgap and trap energy. These findings underscore the importance of precise chemical composition control for reliable TS performance. Insights from this study can guide nanoscale analyses of bonding structures in Te-based binary TS systems and present opportunities for material optimization across various applications.

Comprehensive DFT study of ZnGe1-xSixAs2 alloys: Insights into structural, electronic, optical, and thermoelectric properties

The substitution of Ge with Si in the ZnGeAs₂ chalcopyrite semiconductor and its impact on structural, electronic, optical, and thermoelectric properties have been systematically studied using density functional theory. This study demonstrates the tunability of material properties through alloying, revealing novel insights into the ZnGe₁₋ₓSiₓAs₂ (x = 0–1) system. The exchange-correlation energy was evaluated using the local density, generalized gradient, and modified Becke-Johnson schemes, ensuring accurate predictions. The calculated structural parameters and band gap energies for ZnGeAs₂ and ZnSiAs₂ exhibit excellent agreement with experimental data, validating the reliability of our approach.Both ZnGeAs₂ and ZnSiAs₂ exhibit semiconductor characteristics with a direct band gap at the Γ point, making them promising for optoelectronic applications. The alloys show anisotropic optical behavior, with ZnGe₀.₂₅Si₀.₇₅As₂ demonstrating the highest refractive index and energy loss, making it a strong candidate for UV-shielding and optoelectronic devices. Thermoelectric analysis identifies ZnGe₀.₇₅Si₀.₂₅As₂ as the optimal composition, achieving a maximum Seebeck coefficient of 228.26 μV/K at 800 K. Moreover, by tuning the carrier concentration to n = 4.87 × 101⁸ cm⁻³, the Seebeck coefficient can be significantly enhanced to 449.44 μV/K. These findings highlight the potential of Si substitution to enhance material performance and provide a roadmap for tailoring the structural, optical, and thermoelectric properties of chalcopyrite semiconductors.

Bioimaging potential: Comparative study of ZnO nanoparticles synthesized via green and chemical routes

Zinc Oxide Nanoparticles (ZnO NPs) were synthesized through chemical and green synthesis methods employing Ficus religiosa (peepal) leaf extract. The synthesized nanoparticles underwent comprehensive characterization using various techniques such as Powder X-ray Diffractometry (PXRD), Fourier-transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Photoluminescence (PL), UV–visible Spectroscopy, and Spectroscopic Ellipsometry. The PXRD analysis confirmed a hexagonal wurtzite structure with excellent crystallinity in the product. UV–visible studies indicated band gap energies of 3.13 eV and 2.7 eV for green-synthesized and chemically synthesized ZnO NPs, respectively. There was notable augmentation in the fluorescence characteristics of ZnO NPs derived through green synthesis when compared to chemically synthesized NPs. This observed enhancement in fluorescence renders the green-synthesized ZnO NPs particularly advantageous for bio-imaging.

Studies of Structural and Optical Properties of Nickel Chloride and Glycine Doped Potassium Hydrogen Phthalate (KHP) Crystal

A semi-organic single crystal of potassium hydrogen phthalate (KHP, K(C6H4COOH.COO)) doped with Nickel Chloride (NiCl2) and Glycine (C₂H₅NO₂) was successfully harvested at room temperature to enhance the characteristics of KHP using a slow evaporation approach. The concentration of 1 mol % of Nickel Chloride and 6 mol % Glycine was used during the fabrication of the Nickel Chloride and Glycine doped KHP single crystal. Powder X-Ray diffraction (XRD), ultraviolet visible spectroscopy (UV-Vis), and Fourier transform Infrared (FTIR) analysis were used to analyze the grown single crystal. Powder XRD investigation verified an orthorhombic crystal structure and lattice parameter .To evaluate optical energy band gap and optical transparency using UV-Vis spectral. According to, FTIR analysis, and dielectric studies, it is evident that the crystal modification noticeably by adding dopant.

Evolution of tunable energy bandgap and magnetic anisotropy in Mn substituted ferrimagnetic nickel-chromates

We report a detailed study on the composition (x) dependence of structural, electronic, magnetic, and optical studies of nickel chromate spinel (NiCr2O4) at various levels of Mn substitution at B sites. No significant structural distortion from cubic symmetryFd-3m was noticed for all the compositions in the range 0 ⩽x⩽ 1 of Ni(Cr1-xMnx)2O4. However, there is significant alteration in the bond angles∠B-O-B (90.51°-93.86°) and∠A-O-B (122.48°-124.90°) (both of which follow completely opposite trend with increasingx) and bond lengths A-O (1.82-1.94 Å) and B-O (2.02-2.08 Å). The corresponding lattice parameter (a) follows Vegard's law (8.32 ± 0.001 Å ⩽a⩽ 8.45 ± 0.001Å). The electronic structure determined from thex-ray photoelectron spectroscopy reveals the divalent nature of Ni (with spin-orbit splitting energy Δ ∼ 17.62 eV). While the Cr and Mn are stable with trivalent electronic states having Δ=8 and 11.7 eV, respectively. These results are in consonance with the cationic distribution (Ni)A[(Cr1-xMnx)2]BO4obtained from the Rietveld refinement analysis. Interestingly, the current series shows a direct bandgap (EG) semiconducting nature in whichEGvaries from 1.16 to 2.40 eV within the range ofx= 0.85-0. Such variation ofEG(x) is consistent with the compositional variation of the crystal structure data with anomalous change betweenx= 0.25 and 0.6. Beyond this range, theEgmode (140 cm-1) in Raman spectra arising from Mn-O octahedral decreases continuously and vanishes at higher Mn concentrations. Our analysis shows that all the investigated compounds show long-range ferrimagnetic ordering below the Néel temperature,TFNdue to the unequal magnetic moments of the cations. However, both the ordering temperatureTFNand saturation magnetization (MS) increases progressively from 73.3 K (1500 emu mol-1) to 116 K (3600 emu mol-1) with increasing the Mn content from 0 to 1, yet the maximum anisotropy (HK~4.5 kOe,K1~2.5 × 104erg cc-1) shows an opposite trend withx. Such variation is ascribed to the altered magnetic superexchange interactions between the cations located at A and B sites following the trendJBB>JAB>JAA, (JBB/kB=13.36 K).

Dielectric Characteristics of Iridium Substituted Co0.05-xTi0.95O2 Dilute Magnetic Semiconductors for Electrical Device Applications

In the current study, a cost effective solid-state method have been used to prepare iridium (Ir) substituted and cobalt doped titanium dioxide (TiO2) dilute magnetic semiconductors (DMS) materials {i.e.; IrxCo0.05-xTi0.95O2; 0.00 ≤ x ≤ 0.05 DMS}. The impact of Ir substitution on structural, optical and dielectric properties for the prepared IrxCo0.05-xTi0.95O2; 0.00 ≤ x ≤ 0.05 DMS samples have been investigated using X-ray diffractometer, ultraviolet-visible spectroscopy and LCR (inductor, capacitor and resistor) meter, respectively. The structural analysis confirms the tetragonal rutile phase formation with space group p42/mnm-136, while the values of band gap energy increase with increasing Ir concentrations in prepared DMS materials and band gap value approaches the band gap energy of void band gap materials for large applications. The dielectric constant and tangent loss have been studied as a mapping of frequency (20Hz - 20MHz) at room temperature. Both the dielectric constant and tangent loss linearly decrease with increase in applied frequency and become stable at high frequency values, therefore, these DMS materials could be beneficial for storage and electrical device applications.

Holmium ions influence in structural and optical properties of Aluminium Strontium-phosphate glasses for radiation shielding applications

This study details the synthesis of a novel series of Holmium-doped Aluminium Strontium-phosphate glass (HoAlSr- phosphate glass) composed of 55 P2O5 + 5 Al2O3 + 4 MgO + 5 NaF + 10 LiCO3 + 5 CaO + 10 SrCO3 + 5 ZnO + 1 Ho2O3 prepared by melt-quench method and its structural, optical, and physical properties are analysed. Powder −XRD verified its amorphous nature, FTIR shows the existence of large phosphate functional groups, Optical properties such as band gap energy was calculated by acquiring absorption spectra covering the UV, Vis, and NIR ranges. Obtained 3.02 eV optical band gap energy. The refractive index changing with increasing energy. Three peaks in the PL spectra corresponded to Ho3+ transitions: 5I8→ 5G6, 5I8→ 3K8, and 5I8→ 5F3. The glass conducted theoretical studies for radiation shielding properties based on several key parameters. Gamma radiation shielding parameters, including Mean Free path (MFP), Effective atomic number (Zeff), linear attenuation coefficient (LAC), and mass attenuation coefficient (MAC), were obtained with the use of the Phy-X program. MAC data show that when Compton scattering (CS) fluctuates in the intermediate photon energy zone (E > 3 MeV), the area of prominence of CS diminishes. They can cause pair production at higher energies, Compton scattering at intermediate energies, and the photoelectric effect at lower energies. The MFP values of glasses doped with HoAlSr- phosphate glass were shorter, indicating a higher level of shielding efficacy. In this study we are focusing on optical properties changes with presence of Holmium ions and its shielding property using Phy-x software. In this research discovered that the synthetic material has high shielding qualities and can be a valuable shield in environments where X-rays are present. So it will be beneficial at X-ray prompted environment

Gadolinium doped lithium aluminum borate [Li3Al3(BO3)4:Gd] materials synthesized and characterized for its structural, optical and thermoluminescence properties for use in dosimetric application

Lithium aluminum borate materials was made ready for dosimetric uses in radiation processes. In order to enhance the structural and dosimetric qualities, varying mole concentrations of gadolinium were added to samples of lithium aluminum borate materials. High temperature solid-state technique was used in producing the lithium aluminum borate material. The characterization of the material was archived by using Scanning electron microscope, X-ray diffractometer, thermal gravimetric evaluation, UV-vis-NIR spectrophotometer and thermoluminescence reader/irradiator in other to determine for their structural, thermal analysis, optical properties and dosimetric properties respectively. The kinetic analysis of the major glow peak yielded the activation energy. The crystalline sizes of the undoped and gadolinium-doped Li3Al3(BO3)4 materials were reported to be approximately 36.38 nm and 68.84 nm, respectively, which relies on their matching peaks at a 2θ angle of 25.79o. The grain size for the undoped and gadolinium doped lithium aluminum borate were found within a given range of values 140 – 160 nm, and 80 – 100 nm respectively. The optical energy band gap was found within 3.90 eV to 4.35 eV for the gadolinium doped while the undoped is 3.00 eV for lithium aluminum borate respectively. A larger energy band gap of lithium aluminum borate was observed after gadolinium was incorporated as dopant. The phosphor of lithium aluminum borate doped with gadolinium was observed to exhibit prominent TL intensity peaks at 100 oC following irradiation. The irradiated samples of lithium aluminum borate doped with gadolinium showed a dose response that was linear between 20 and 150 Gy. This work demonstrates the potential use of Gd-doped lithium aluminum borate phosphor in radiation dosimetry.

Insights into Selective Sensitivity of In2O3-CuO Heterojunction Nanocrystals to CH4 over CO and H2: Experiments and First-Principles Calculations.

Metal oxide semiconductor gas sensors have demonstrated exceptional potential in gas detection due to their high sensitivity, rapid response time, and impressive selectivity for identifying various sorts of gases. However, selectively distinguishing CH4 from those of CO and H2 remains a significant challenge. This difficulty primarily stems from the weakly reducing nature of CH4, which results in a low adsorption response and makes it prone to interference from stronger reducing gases in the surroundings. Herein, we synthesized In2O3-xCuO nanocomposites using a hydrothermal method to explore their gas sensing properties toward CH4, CO, and H2. Characterization tests confirmed the successful preparation of In2O3-xCuO nanocomposites with different In:Cu molar ratios and the formation of a p-n heterojunction. The gas sensing test results indicated that the In2O3-2.1CuO nanocomposites calcined at 500 °C and measured at 350 °C displayed a p-type response for CH4 and an n-type response for CO and H2, allowing for accurate differentiation of CH4 from CO and H2. Moreover, the In2O3-2.1CuO sensor also showed excellent stability and reproducibility across all three gases. First-principles calculations revealed distinct changes in the electronic structure of the In2O3-CuO heterojunction upon adsorption of CH4, CO, and H2, a finding that aligns with empirical evidence. The gas selectivity mechanism was effectively explained by variations in the energy band gap, driven by electrical behavior during the adsorption process. This work suggests a promising approach for developing selective gas sensors capable of detecting weakly reducing gases.

Predicting Optical Properties of NiO Films Fabricated by RF Magnetron Sputtering: A Machine Learning Approach

NiO films with different thicknesses (100, 150, 200, 250, 300 and 400nm) were grown on glass substrates using the RF Magnetron sputtering method and their optical transmittance properties were analysed with a spectrophotometer. An innovative aspect of this work was the application of machine learning techniques used to derive new insights from experimental data. Four different machine learning algorithms -ANFIS, Artificial Neural Networks (ANN), Support Vector Machines (SVM) and Gaussian Process Regression (GPR)- were tested. While the models were trained using films of different thicknesses, a randomly selected 75% of the whole dataset was used for model testing and the remaining 25% of the films were used for testing the models. Among these, ANN and GPR models were found to be the most successful models. Using these models, the energy band gaps were estimated at 1nm intervals and the values ranged from approximately 3.50eV to 3.76eV.

Optimization of Several Parameters Towards 30% Efficiency Perovskite Based Solar Cell Using SCAPS-1D Software

A simulated perovskite solar cell based on a P3HT/MAPbI3/C60 structure is examined to achieve 30% PCE using SCAPS-1D software. Several aspects of the perovskite layer were evaluated, including the perovskite layer thickness, CB and VB effective density of state, band gap, and electron affinity. These factors show great influence on the device performance. The best device based on the best examined parameter has exhibited a PCE of 32.1% correlated with FF of 84.8%, VOC of 1.23V and JSC of 30.77 mA.cm-2. Such a result is promising towards achieving high PCE for perovskite-based solar cells by optimizing several factors, including active layer thickness, energy band gap, electron affinity, and effective state density for CB and VB. However, for the experimentally produced solar cells, the preparation condition and other factors may render this result. A low effective DOS of (1x1016m-3) is desired for both CB and VB to achieve high solar cell performance.

Investigating the performance of Tin-based perovskite solar cell with Cadmium Sulphide as etm and graphene as htm using SCAPS-1D

Solar cells based on lead-free perovskite have demonstrated great potential for renewable energy. The SCAPS-1D simulation software was used in this study to perform device modelling of a lead-free perovskite solar cell of the architecture Glass/FTO/CdS/CH3NH3SnI3/Graphene/Pt. For the performance evaluation, an optimization process of the different parameters such as thickness of the ETM, Absorber, Bandgap energy of the hole transport material was conducted. Extensive discussion on its effect on the performance of the solar cell parameters were stated. An optimal ETM and Absorber layer thickness was achieved at 40nm and 950nm. The Bandgap energy gave an optimal performance of device parameters at 0.9eV. Temperature variations were simulated and it was noted that the device had a minimal decrease in PSC parameters performance with increasing temperature. The final optimized device structure achieved a PCE, Voc, Jsc and FF of 25.65%, 0.9606 V, 33.2491(mA/cm2), and 80.32% respectively. Therefore, we expect that our findings will pave the way for the development of lead-free and highly effective perovskite solar cells.

Predictions of spin-valley properties in ferromagnetic Janus 2H-CeXY (X, Y = Cl, Br, I, X ≠ Y) monolayers: Merger of valleytronics with spintronics

In this work, the Janus 2H-CeXY monolayers are predicted as 2D intrinsic ferrovalley materials with bipolar ferromagnetic (FM) semiconductor characters, high Tc of 511–540 K, robust in-plane/perpendicular magnetic anisotropy (IMA/PMA) and spontaneous valley polarization through first-principles calculations. The d-p-d indirect exchange interaction between the Ce atom and X(Y) atoms is responsible for the observed FM ordering. Applying the biaxial strain ε from −6 % to 6 %, the Janus 2H-CeXY monolayers keep energy bandgap and large magnetic anisotropy. While a transition from PMA to IMA character is observed for the 2H-CeBrCl monolayer, which is due to the competition between Ce-p/d and Br/Cl-p orbitals. The intrinsic magnetic interaction and strong SOC effect induce a large spontaneous valley polarization of 29.1–78.7 meV for the Janus 2H-CeXY monolayers, which is also robust under various ε. Besides, the anomalous valley Hall effect (AVHE) can be observed due to the nonzero Ωz(k) induced by the broken space/time-reversal symmetry. Overall, the Janus 2H-CeXY monolayers provides a new candidate for the spintronic and valleytronic devices.

Antibacterial and anti-biofilm activities of gold-curcumin nanohybrids and its polydopamine form upon photo-sonotherapy of Staphylococcus aureus infected implants: In vitro and animal model studies

Implant-related infections are among the major post-surgery problems, and treatment of these infections is challenging due to the formation of biofilms by microorganisms such as Staphylococcus aureus. Herein, a novel gold-curcumin nanohybrid (GCNH) was synthesized for the first time and characterized. GCNH had a band gap energy of 2.41 eV, a zeta potential of −15 mV, and comprised uniform spherical particles with a mean diameter of 8 ± 2 nm. The biological macromolecule of polydopamine was then coated on GCNH to prepare a gold-curcumin-polydopamine nanohybrid (GCDNH). The nanohybrids were employed as novel dual photo-sonosensitizers for bacterial eradication by near-infrared (NIR) light and ultrasound (US) irradiations. GCNH and GCDNH represented photothermal conversion efficiencies of 26 and 32 %, respectively, and GCDNH represented a hemolysis rate of 2.3 % under both near-infrared (NIR) light and ultrasound (US) irradiations. NIR light and US irradiations (photo-sonotherapy) of Staphylococcus aureus using GCDNH depicted anti-bacterial and anti-biofilm efficiencies of 98 and 99 %, respectively, in synergistic manners, which are higher or as high as other sensitizers reported previously. The mechanism of photo-sonotherapy was related to generation of high levels of reactive oxygen species (ROS), and protein and nucleic acid leakages. In an in vivo infection model, NIR light and US irradiations annihilated Staphylococcus aureus on GCDNH-covered implants with high efficiency, without causing damage to normal tissues.

Tecoma stans intermediated green synthesis of copper oxide nanoparticles, its characterization, paracetamol degradation and biological activities

The main objective of the present research work is to green synthesize copper oxide nanoparticles (CuO NPs) and to study its potential against various enmities to safeguard our environment and health. Based on this approach, preparation of CuO NPs was accomplished using four different volumes (10, 25, 40, and 50 mL of leaves extract) of Tecoma stansleaves extract. Moreover, all the synthesized CuO NPs were characterized using XRD, UV–visible, FTIR, and SEM with EDS analysis. From the XRD pattern, the structures of all the synthesized CuO NPs were found to be monoclinic in phase. According to the UV–visible studies, the calculated band gap energy values for all the prepared CuO NPs were higher compared to bulk CuO, which was 1.2 eV. Further, the FTIR results showed the presence of CuO bond and SEM with EDS analysis revealed the surface morphology of CuO NPs andthe presence of elements showing the purity of synthesized CuO NPs, respectively. The optimized condition for the preparation of CuO NPs were 50 mL of leaves extract mixed with 50 mL of double distilled water (CuO4 NPs) showed a spheroidal morphology as evident from the HRTEM images. XPS analysis used to find the oxidation state of detected elements especially for copper and oxygen. The predicted BET and Langmuir surface area of CuO4 NPs were calculated to be 40.305 m2/g and 5074.12 m2/g respectively. Photocatalytic degradation of paracetamol (PCM) using CuO4 NPs was investigated, and the effect of parameters such as pH, initial concentration of PCM solution, and catalyst dosage were studied under UV light irradiation. The highest removal of 95.15 % had been achieved at 120 min under optimized reaction conditions. Additionally, CuO4 NPs also exhibited exemplary antibacterial activity against bacillus subtilis bacteria with a zone of inhibition of 26 mm. Further, in vitro cytotoxic behaviour of CuO4 NPs was estimated using A549 cancer cells by MTT assay. Thus, the green synthesis of CuO NPs using Tecoma stans leaves extract has the capacity to participate in photocatalytic and biological activities.

Dual functional covalent triazine framework-TiO2 S-scheme heterojunction for efficient sequestration of ciprofloxacin: Mechanism and degradation products

The development of adsorbent and/or photocatalysts based on covalent triazine frameworks (CTF) is fascinating research due to their structural properties, functional groups, and active sites. Herein, a CTF-TiO2 heterojunction was synthesized by modifying CTF sheets with TiO2 particles through wet impregnation technique and adsorptive and photocatalytic activities determined for ciprofloxacin (CIP) removal. Comprehensive characterisation of the composites revealed suitable properties of the composites, such as sandwich-like CTF-TiO2 morphology, improved thermal stability, and better heteroatom effect (HAE). The adsorption capacity of CTF-TiO2-1 (CT-1) and CTF-TiO2-2 (CT-2) reached 30.30 mg g-1 and 13.61 mg g-1, respectively. Meanwhile, the CT-2/H2O2 system, compared to all other materials, achieved a better degradation efficiency of 90.7 % within 40 min compared to 77.5 % observed in using only CT-2 for 120 min. In addition, scavenging results suggested that e- and h+ was crucial for the effective degradation of CIP. Identification of the degradation product of CIP suggests hydroxylation, decarboxylation, and opening of the quinolone and piperazine ring as possible degradation pathways. The mineralization of CIP was 90.93 % for the CT-2/H2O2 system and its stability maintained for four cycles. The outstanding performance of CT-2 is attributed to its enhanced band gap energy of 2.86 eV, and reduced recombination rate of photogenerated electrons and holes. These results prove these materials are efficient adsorbent/photocatalyst in CIP removal from solution.

Study the Structural and Optical Properties (Energy Gap) of Polythiophene/MWCNT/SnO2 Nanocomposite as an NO2 Gas Sensor

The polythiophene (PTh) is of great interest in various applications due to its unique electrical, mechanical and structural. In this work, PTh was synthesized using the oxidation method by employing ferric chloride (FeCl3) as an oxidizing agent, Then the nanocomposite polythiophene: Multi walled carbon nanotubes: Tin (IV) oxide (PTh/MWCNT/SnO2) was prepared by adding constant weight ratio of MWCNT(0.7g) and different weight ratios of SnO2 (0.1, and 0.5g) using the oxidation method. The FE-SEM images of the pure PTh and the nanocomposite showed an apparent change in the morphological composition of the surface. The X-ray diffraction (XRD) pattern of PTh/ MWCNT/SnO2 nanocomposites show the appearance of clear peaks for SnO2, while there are broad peaks for MWCNT. As for the polymer, its behavior is random. The morphology of these nanocomposites shows that the nanotubes were not well aligned and were randomly entangled. The Fourier transformer infrared (FT-IR) spectra of the pure and nanocomposite samples prepared by chemical method in the range of 450-4000 cm-1 wave number are recognized the chemical pledges (bonds) as well as functional groups in the compound. The band gap energy decreased from 3.53 into 2.78 and 2.97 when SnO2 was added. The sensitivity of the two nanocomposites shows a good enhancement 14.6% and 62% at temperature 150oC as gas sensor.

Boosting nickel nanoferrite’s specific capacitance with Azadirachta Indica for advanced supercapacitors

Nickel Ferrite (NiFe2O4) a valuable transition metal oxide possessing a spinel structure, it is extensively utilized in industry due to its compelling properties. In this present study the sol–gel auto-combustion synthesis method was employed using nitrates and citric acid in conjunction with double distilled water (DDW) and Azadirachta Indica extract. The X-ray diffraction (XRD) analysis revealed the formation of a cubic spinel phase with high crystallinity. Crystallite size of prepared Nickel Ferrite in double distilled water and Azadirachta Indica by Scherrer’s equation and Williamson-Hall plot (W-H) are 28.09 nm and 33.01 nm as well as 16.23 nm and 16.55 nm, with microstrains of 0.32739 % and 0.339 × 10−3 % respectively. The notable reduction in the crystallite size is observed when employing Azadirachta Indica compared to the double distilled water-based synthesis. The X-ray density of the synthesized sample in double distilled water and Azadirachta Indica are obtained as 3.935 (g cm−3) and 5.427 (g cm−3). Transmission electron microscopy (TEM) of Azadirachta Indica-based nanostructured Nickel Ferrite material exhibited a particle size of 17.06 nm. The study encompassed the calculation of various parameters such as hopping lengths, polaron radius, specific surface area, packing fraction, and dislocation density. Magnetic parameters are comprehensively examined using a vibrating sample magnetometer (VSM), revealing a Bohr magneton is 3.278. The shifting of coercivity curve observed towards right due to exchange bias effect and the unidirectional anisotropy for diamagnetic Azadirachta Indica based Nickel ferrite. Optical properties are investigated through UV–VIS and Fourier-transform infrared (FTIR) spectroscopy, resulting in a band gap energy of 1.75 eV and a porosity is 11.16 %. Electrochemical evaluation of Nickel Ferrite electrodes is conducted over a potential range from 0.0 to 1 V. The specific capacitance of Nickel Ferrite electrodes synthesized with double distilled water and Azadirachta Indica are determined as 511.9 F/g and 695 F/g respectively, at a scan rate of 50 mV/s, as evaluated through cyclic voltammetry (CV) measurements in Ag/AgCl (0.1 M NaOH as electrolyte). The specific capacitance of Nickel Ferrite, produced with double distilled water and Azadirachta Indica extract, is 686 F/g and 817.398 F/g respectively, as determined by Galvanostatic charge–discharge (GCD) measurements. The study conclusively demonstrated significantly improvement in the electrochemical performance of Nickel Ferrite, synthesized with Azadirachta Indica extract for supercapacitor application. Based on GCD and CV, the specific capacitance has been boosted significantly with Azadirachta Indica extract for supercapacitor application.

SnO2-TiO2/reduced graphene oxide nanocomposites: Green synthesis and enhanced photocatalytic efficiency for dye removal

Titanium oxide nanoparticles (TiO2 NPs) have been interested in potential applications, including gas-sensing, energy storage, environmental remediation, and medical fields. In the present work, fabricated SnO2-TiO2/RGO nanocomposites (NCs) have been produced through a green precipitation approach. XRD, TEM, SEM, EDX, XPS, FTIR, UV, and PL analyses have been carefully applied to invistage the physicochemical properties of prepared NPs and NCs. The XRD data showed that the crystal structure of the TiO2 NPs was affected by the introduction of SnO2 NPs and RGO sheets. The spherical shape of the prepared samples and their morphologies were confirmed using TEM and SEM images. EDX and XPS analyses confirmed that tin (Sn), titanium (Ti), oxygen (O), and carbon (C) were further present in the SnO2-TiO2/RGO NCs. FT-IR spectra determines the functional groups with bands between the compositions of obtained NPs and NCs. Besides, the band gap energies of prepares samples were estimated from UV–vis spectra. It displayed that the absorption peak of the synthesized TiO2 NPs was improved after the addition of SnO2 NPs and an RGO sheet. PL analysis indicate that the PL intensity of the prepared TiO2 NPs was decreased with the addition of SnO2 NPs and RGO sheets due to a decrease in the recombination rate of electrons (e−)-holes (h+). As shown in photocatalytic results, the photodegradation of methylene blue (MB) dye of SnO2-TiO2/RGO NCs was reached 92.20% after 140 min of UV irradiation. These results suggest that the addition of RGO sheets occupied a role in enhanced the photocatalytic performance of the prepared NCs. This study highlighted that these samples could be applied in various applications such as photocatalytic and therapeutic areas.

Optimizing Dye-Sensitized Solar Cell (DSSC) Performance through Synergistic Natural Dye Combinations from <i>Beta vulgaris</i> L., <i>Curcuma longa</i> L., and <i>Pandanus amaryllifolius</i>

This study optimizes dye-sensitized solar cell (DSSC) performance using a combination of natural dye components extracted from Beta vulgaris L. (beetroot), Curcuma longa L. (turmeric), and Pandanus amaryllifolius (pandanus leaf). These plants were selected for their natural pigments—betacyanin, curcuminoids, and chlorophyll—which potentially act as DSSC sensitizers. Dyes were extracted via maceration with ethanol solvent (1:6 sample:solvent ratio) for 24 h. Filtrates were combined in various ratios to test DSSC performance. The optimal C4 dye combination, with a 2:1:1 ratio (betacyanin:curcumin:chlorophyll), demonstrated the best performance. The UV-vis analysis revealed complex interactions and synergistic effects among dye combinations, characterized by increased light absorption in the 400–700 nm range. Cyclic voltammetry analysis showed favorable energy band gap values, confirming the pigments' suitability for DSSC applications. FTIR analysis confirmed the stable coexistence of the three dyes without new bond formation. Photovoltaic performance testing showed the C4 three-dye combination achieved the highest energy conversion efficiency of 3.57%. These results demonstrate the potential of this dye combination to contribute to the development of sustainable and efficient solar energy conversion in DSSCs.