The polymer electrolyte membrane functions as both an electrolyte and a separator within an energy storage device. This article provides an analysis of the performance of the manufactured electric double-layer capacitors (EDLC) using plasticized lithium ion conducting poly (lactic acid) (PLA) based solid polymer electrolytes (BPEs). At present, the electrolyte employed in EDLC often consists of aqueous, organic, or liquid salts/ionic liquids. However, these electrolyte options are often accompanied by issues like leakage, self-discharge, corrosion, and bulky design. Therefore, the objective of this work is to explore the potential of Plasticized PLA BPEs as a solid-based form for EDLC application, with the aim of mitigating the issue and evaluating its performance. This study focuses on characterizing the complexes of LiCF3SO3- PLA with varying weight percentages of polypropylene carbonate (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, and 25 wt.%). The high-conducting samples were then utilized for application in EDLC, and the performance of the EDLC was further studied. It is specified that the transference numbers of ions (tion) and electrons (tel) are 0.98 and 0.02, correspondingly. As determined by linear sweep voltammetry (LSV), the potential window is 7.10 V. Electrodes for the EDLC were manufactured utilizing the preferred combination of activated carbon (AC) and carbon black. By sandwiching the Plasticized PLA BPEs between two carbon-based electrodes, cyclic voltammetry (CV) was performed, which disclosed an almost rectangular shape. The EDLC demonstrated average values of 158.89 Ω for equivalent series resistance, 46.5 F/g for specific capacitance and 0.987 Wh/kg for energy density. The initial power density was determined by the EDLC to be 130 W/kg. In conclusion, plasticized lithium ion conducting PLA BPEs were successfully fabricated and employed in EDLC applications.

Titanium dioxide (TiO2) is a semiconductor material that widely used in numerous applications due to its exceptional physical and chemical properties. This study explores the structural, electronic and elastic properties of TiO2 phases in rutile, anatase and brookite under hydrostatic pressure up to 100 GPa. At 0 GPa, the computed lattice parameters and volumes align closely with experimental data. The band structure reveals that rutile and brookite exhibit direct band gaps while anatase shows an indirect band gap. Elastic properties including bulk modulus, shear modulus, Young’s modulus, Cauchy pressure, Pugh ratio and Poisson’s ratio were calculated using the Voigt-Reuss-Hill approximation. Our findings confirm the mechanical stability of all TiO2 phases and offer insights that align with existing theoretical and experimental data. These findings provide a comprehensive understanding of behavior of TiO2 under high-pressure condition which is crucial for optimizing its applications in various fields such as photocatalysis and solar cells.

The influence of bromide and iodide-halides on (H2-2AMP)PbX4 (X = Br and I) compounds, focusing on their structural, chemical, and optical characteristics was investigated in this study. Synthesized via a reflux method under a nitrogen atmosphere, the compounds were analyzed using FT-IR spectroscopy and XRD analysis. Despite differing halides, both compounds share an orthorhombic crystal structure, with distinct cell parameters and bond lengths. The UV-Vis analysis reveals significant tuning of the cut edge within the visible range, offering insights into their potential of the materials in optoelectronic applications.

The new materials like quaternary chalcogenides semiconductors is an approach towards environment-friendly photovoltaic materials due to their promising potential as thin film solar cell absorbers. This work investigates the density functional theory (DFT) and density functional theory plus Hubbard U (DFT + U) approach on the kesterite phase of sulfide-based chalcogenides, Cu2XSnS4, CXTS (X = Zn and Fe) materials. The inclusion of the potential correlation term, U, plays a vital role in aiding the understanding of the complex many-electron problem, which LDA and GGA from DFT might not adequately describe. It was found that, by applying Hubbard U terms on p and d orbital states, the value of electronic band gaps can be significantly fixed close to the experimental value (similar to 1.3 eV-1.5 eV). The parametrized dependence of the band gap was well explained. The investigation of optical properties associated with the thin film applications on imaginary parts of the dielectric function shows that both structures have greater absorption at the energy range of 0-5 eV. Moreover, the refractive index and optical absorption show good results for both kesterite CXTS in the most effective wavelength of light to absorb sunlight (visible spectrum), which could exhibit a better finding for a suitable candidate for cost-effective new thin film solar cell application.

Poly(N-vinylcarbazole) has been widely used in polymer light emitting diodes due to its unique electronic properties. The electronic properties of Poly(N-vinylcarbazole) were examined using the Semi-Empirical Zerner Modified Intermediate Neglect of Differential Overlap (ZINDO) oligomer extrapolation method. In this calculation, the electronic properties of Poly(N-vinylcarbazole) were extracted from oligomer electronic properties. We identified a tendency for oligomers with large HOMO-LUMO gaps in the form of linear regression as function of reciporocal of monomeric units. The increasing number of monomers induce the interaction between energy levels of each monomer which boardening the energy levels. The localized molecular orbital and vibration spectra of the basic unit of polymer Poly(N-vinylcarbazole) also has been investigated.

We reported first-principle calculations on the structural and electronic properties of layered sodium iron(II) hydroxysulfate, NaFeSO4OH as a potential cathode for sodium-ion battery. Layered NaFeSO4OH was virtually derived from the experimentally reported layered LiFeSO4OH by replacing Li with Na. A redox voltage of 3.00 V was computed along with the theoretical capacity of 140 mAh/g, yielding an energy density of 420 Wh/kg. The electronic band gap is predicted to be similar to the Li counterpart of the material. This material has some valuable positive attributes, including high capacity and energy density, sturdy host structure as well as being made up of abundant elements.

The origin of spinel cobaltite properties can be attributed to the cation distribution between tetrahedral and octahedral coordination. The choice of spinel types is primarily considered due to the different octahedral and tetrahedral crystal fields where the degeneration of the 3d orbital is different and could lead to dissimilar electronic properties. In this work, a theoretical study based density functional theory (DFT) by using CASTEP was performed on Ni-doped Co3O4 (NiCo2O4) to explore the structural, magnetic and electronic properties. From the computed inversion energy and formation energy study, the resulting NiCo2O4 is energetically favorable in inverse spinel type where Ni prefers to substitute with Co at the octahedral site. The result revealed that the substitution of Ni cation has substantially changed the structure from cubic to tetragonal due to the elongation of the Ni-O bonding at the octahedral site which caused Jahn-Teller (JT) distortion. DOS results showed that NiCo2O4 has transformed from semiconductor Co3O4 into half-metallic material as seen in the spin-down channel which crossed the Fermi level. In addition, details of octahedral crystal field splitting have demonstrated the reason for Jahn-Teller distortion in NiCo2O4.

Ni-Co hydroxides with different Ni:Co ratio were synthesized using 2-electrode electrodeposition method. The effects of Ni:Co with different ratio on the hydroxides’ structural and optical properties were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) method and scanning electron microscopy (SEM). The shifting, changing in shapes and intensity of the corresponding Ni(OH)2 and Co(OH)2 characteristic bands in Ni-Co hydroxides FTIR spectra confirmed that the Ni-Co hydroxides were successfully deposited onto the substrate’s surface. SEM micrographs of Ni-Co hydroxides also showed that all corresponding particles were uniformly distributed and meet the ratio of Ni:Co accordingly. Moreover, XRD patterns confirmed the amorphous nature of nano-sized Ni-Co hydroxides as they were thinly coated. The effects of cobalt on the physical and electrochemical properties of Ni(OH)2 were also investigated. SEM images of Ni-Co hydroxides portrayed that cobalt creates flower-like pores on Ni(OH)2 surface where such pores are important for facile ions diffusion for better electrochemical performance. The Ni-Co hydroxides’ electrochemical properties were also characterized by means of cyclic voltammetry and electrochemical impedance spectroscopy. It was further confirmed in the cyclic voltammetric and impedance spectroscopic studies that Ni:Co=1:3 ratio has the best electrochemical performance.

DFT simulations are used to determine the most appropriate approach to reproduce the experimental electronic structure and optical properties besides providing the reliable structural stability of CH3NH3PbI3. In this work, DFT calculations are performed using the generalized gradient approximation (GGA) that includes spin-orbit coupling (SOC) and empirical pairwise dispersion of the DFT + D method to investigate the structural, elec-tronic, optical and mechanical properties of the material. Our results reveal that SOC effects reduced the band gap compared to GGA functional alone. Meanwhile, using the DFT + D method, an improvement in the calcu-lation accuracy of the band gap obtained (1.689eV) is in excellent agreement with the experimental (1.630eV). Further analysis of the electronic properties demonstrates that including SOC reduces the effective masses of electrons due to the creation of splitting at the bottom of the conduction band. We have presented the absorption coefficient to describe the optical properties. It is found that CH3NH3PbI3 exhibit stronger optical absorption in the UV light region (300-400 nm). The mechanical properties of Young's modulus, bulk modulus, shear modulus and Poisson's ratio were calculated using DFT + D. It was discovered that the ratio (B/G) achieved was greater than 1.75, indicating that CH3NH3PbI3 is a ductile material.

The first principle study on structural, electronic, and optical properties of 2D hybrid halide compound (2-AMP)BI 4 (B = Pb, Sn) was analyzed using CASTEP computer code. The calculations were performed using generalized gradient approximation (GGA) schemes. This study aims to look at a few characteristics of (2-AMP)SnI 4 as a potential replacement for (2-AMP)PbI 4 as a light absorber in solar cell applications due to its toxicity to humans and the environment. The results show that the substitution of lead (Pb) with tin (Sn) can replace Pb-based hybrid halide perovskite due to low band gap, high optical absorption in UV–Visible area, and improved polarizability of electric current. To conclude, 2D Sn-based solar cells are well suited for light harvesting in solar devices. This research may give some information on the properties of 2D Sn-based solar cells for use in renewable energy applications.

Purpose The purpose of this paper is to investigate the structural, electronic and optical properties of pure zinc oxide (ZnO) and transition metal (Tm)-doped ZnO using Tm elements from silver (Ag) and copper (Cu) by a first-principles study based on density functional theory (DFT) as implemented in the pseudo-potential plane wave in CASTEP computer code. Design/methodology/approach The calculations based on the generalized gradient approximation for Perdew-Burke-Ernzerhof for solids with Hubbard U (GGA-PBEsol+U) were performed by applying Hubbard corrections U d = 5 eV for Zn 3 d state, U p = 9 eV for O 2 p state, U d = 6 eV for Ag 4 d state and U d = 9.5 eV for Cu 3 d state. The crystal structure used in this calculation was hexagonal wurtzite ZnO with a space group of P63mc and supercell 2 × 2 × 2. Findings The total energy was calculated to determine the best position for Ag and Cu dopants. The band structures and density of states show that Tm-doped ZnO has a lower bandgaps value than pure ZnO because of impurity energy levels from Ag 4 d and Cu 3 d states. In addition, Ag-doped ZnO exhibits a remarkable enhancement in visible light absorption over pure ZnO and Cu-doped ZnO because of its lower energy region and extended wavelength spectrum. Originality/value The results of this paper are important for the basic understanding of the 3 d and 4 d Tm doping effect ZnO and have a wide range of applications in designing high-efficiency energy harvesting solar cells.

Two-dimensional (2D) hybrid metal halide perovskite is receiving more interest today due to being more stable and having a higher surface area-to-volume ratio than 3-dimensional (3D) hybrid metal halide perovskites. To create a 2D structure with high-efficiency properties, the A cation in the parental 3D structure should be replaced with a bulky organic cation (BOC). So in this study, we aim to investigate the structural, electrical, and optical characteristics of 2D (2-AMP)PbI4 via CASTEP computer code and density functional theory (DFT). The computations utilize the local density approximation (LDA) and the generalized gradient approximation (GGA) techniques. The structural characteristics of GGA-PBEsol demonstrate great agreement with experiment data. The (2-AMP)PbI4 structure consists of corner-sharing PbI64− octahedra separated by alternating sheets of the double-protonated 2-AMP cation. Due to the spin–orbit coupling (SOC) effect, the electronic band gap was reduced from 1.92 to 0.98 eV. According to the partial density of states (PDOS), the Pb-p and I-p bonds supply the most electrons to the band gap. When it comes to optical characteristics, the actual part of the dielectric function reveals that this compound exhibits plasmonic behavior, which increases its capacity to absorb light. The absorption coefficient of (2-AMP)PbI4 shows that this 2D compound able to absorb light in the range of UV and visible light, making it a possible candidate for high-efficiency solar cell devices.

The hybrid perovskites of amino(methyl) pyridines (AMP) and lead (II) bromide (PbBr 2 ) were synthesised using a reflux method in 40% hydrobromic acid medium in a closed-nitrogen condition. The structural, chemical and optical properties of the as-synthesised compounds were analysed analytically using XRD, FT-IR and UV-Vis. Based on the XRD analysis, all compounds have distinct and evenly spaced diffraction peaks, indicating that they are strongly oriented and well-crystallised. The presence of aromatics and primary amines in mono-substituted pyridinium cation variations was confirmed by the FT-IR analysis. All compounds absorbed strongly in visible spectra at 430 nm, 427 nm and 355 nm, respectively. This study demonstrates that organic-tailoring effects in the shifting of aminomethyl position in the pyridine chain contribute to different dimensionalities of hybrid perovskite frameworks, even when synthesised under the same conditions. The as-synthesised low-dimensional hybrid perovskite can be further utilised as a light-harvester material in Perovskite Solar Cells (PSCs).

The Uncaria Cordata as corrosion inhibitors for mild steel (MS) in a 1.0 M hydrochloric acid (HCl) solution. The EIS, polarization, and LPR measurements were used as experimental measurements to confirm the anti-corrosion performances of the Uncaria Cordata at room temperature. The corrosion inhibitors, even at a low dosage range, achieved inhibition efficiencies to a maximum of 97.0% for 400 ppm of Uncaria Cordata. Surface morphology via AFM and SEM/EDX was carried out to validate the presence of protected film and an optimum concentration of each extract above the metal's surface in the corrosive acidic solution. The Delta G(ads)(o) value - 19.70 kJ/mol proved a spontaneous merge of physical and chemical adsorption by the extract compounds at the interface of MS and the HCl solution. DFT was governed to accommodate the elevated inhibition efficiency upshot obtained by the electrochemical tests and recommend a synergy mechanism for most of the adsorbed active compounds in Uncaria Cordata inhibitors with the MS surface. Monte Carlo simulation indicates three active compounds, namely 1, 2, and 8, found to have parallel adsorption on MS. This encourages the highest surface coverage and shields the MS surface from the intrusion of corrosive agents.

This work imparts a fundamental evaluation on the electronic and optical behavior of optimized zinc cobaltite (ZnCo2O4), computed via Density Functional Theory(DFT), within Cambridge Serial Total Energy Package (CASTEP) framework. By employing two generalized gradient approximation (GGA) and a local density approximation (LDA) at the optimized cut-off energy of 630 eV and 4×4×4 k-points, the electronic and optical properties analysis was successfully deduced. The direct band gap and conductive behavior of ZnCo2O4 have been evaluated by means of band structure and Density of States (DOS) calculation. The dielectric constant, refractive index, and absorption spectrum also reveals the viability of ZnCo2O4 in electronic device application.

Objective: A promising Zn-Ni-Co mixed transition metal oxide was successfully synthesized by means of the sol-gel route and its super capacitive behavior was studied. Methods: The structural, morphology, and functional groups were deduced via XRD, SEM, EDX, and FTIR analysis. The super capacitive performance of the hybrid and ternary mixed transition metal oxides was executed through a three-electrode system, in a 2M KOH electrolyte. Results: The specific capacitance of Zn-Ni-Co O was reckoned to be 415 Fg-1 at 50 mVs-1, thrice as much as the specific capacitance of ZnCo2O4 hybrid transition metal oxide (139 Fg-1). The synergistic effects benefited from multiple metal constituents and low activation energy for electron transportation plays an important role in boosting the electrochemical performance. Conclusion: The obtained results proved that Zn-Ni-Co O ternary composite has a promising future as an alternative for supercapacitor electrodes.

In this work, the first-principles calculations using density functional theory (DFT) was applied to calculate the structural and electronic properties of anatase, rutile and brookite TiO2 phases. The effects of Hubbard U correction on the structural and electronic properties of rutile, anatase TiO2 were explored using the local density approximation (LDA) and generalized gradient approximation (GGA) for Perdew-Burke-Ernzerhof (PBE) and Perdew-Burke-Ernzerhof for solids (PBEsol) method by applying Hubbard corrections Ud in Ti 3d states and Up in O 2p states. There are changes in the structural parameters caused by the Hubbard U correction in Ti d states and O p states. The best agreement of U values to improve the electronic band gap of rutile was found at Ud = 3.0 eV and Up = 7.0 eV from LDA, Ud = 2.0 eV, Up = 6.0 eV from GGA-PBEsol for anatase and Ud = 3.0 eV and Up = 4.0 eV for brookite using GGA-PBEsol. The combination of both Ud and Up correction terms managed to widen the band gap of rutile, anatase and brookite TiO2 which is close to the experimental value.Copyright (c) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of the 8th International Conference on Solid State Science & Technology (8thICSSST 2021).