Band Gap Energy Values Research Articles

Synthesis and characterization of magnetic nanoparticles decorated by carbon layers acting as defenders against bacterial infectious agents

High stability magnetic nanocomposites wrapped by carbon layers were efficiently synthesized using electrical arc powered by single arc unit. This is sufficient to ionize the nickel, and carbon electrodes immersed in distilled water through applying strong electric field between carbon rotatory cathode and nickel anode. Nickle decorated by carbon (Ni@C) nanocomposite was fully characterized by transmission electron microscope (TEM), X-ray Diffraction (XRD), Vibrating-sample magnetometer (VSM), UV/Visible Spectrophotometer (UV), Fourier-transform infrared spectroscopy (FTIR), Particle size analyzer (PZ), Zeta potential, and X-ray photoelectron spectroscopy (XPS). Ni particle was spherical with average size equals to 17 nm wrapped by carbon where its energy band gap values were 2.84 for C, and 3.36 eV for Ni. The estimated phase percentage of nickel was 64.8 % which is higher than the percentage of carbon layers that's donating the sample the observed high stability of zeta potential was found to be 26.4 mV. The saturation magnetization (Ms) and coercivity (Hc) examined were 10.624 emu/g and 80.648 G, respectively. The antibacterial effect of the synthesized nanocomposites was tested against standard ATCC (American Type Colony Collection) strains namely Pseudomonas aeruginosa 27853, Proteus mirabilis 35659, Proteus vurgalis 13315, Klebsiella pneumoniae 13883, and Staphylococcus epidermidis 12228. Proteus vurgalis 13315 was the most resistant strain which wasn't completely eradicated after 24 h incubation with the prepared nanoparticles. Further assessments through confocal microscope and reactive oxygen species (ROS) generation percentage were done to predict the possible antibacterial mechanism of the synthesized nanocomposite. Ultimately, the combined influence of nickel ions and carbon in the prepared Ni@C nanocomposite results in the suppression of bacterial respiration and the induction of oxidative stress, ultimately leading to bacterial cell death.

Photocatalytic degradation of methylene blue using chitosan/NiO nanocomposite: A comprehensive exploration

The present research work aims to illustrate the potential power of chitosan nanoparticles and chitosan/nickel oxide (NiO) nanocomposite for the photocatalytic degradation of methylene blue (MB). Initially, chitosan nanoparticles and chitosan/NiO nanocomposite were prepared using ball milling technique, focusing on the theory of top-down preparation. It was observed that, the as-prepared chitosan/NiO nanocomposite exhibited spherical shape with small size. Meanwhile, chitosan nanoparticles were prepared with irregular shape as depicted from TEM analysis. XRD affirmed the pure phase and crystalline structure of chitosan nanoparticles as a result to the observation for two peaks at 11.3o and 20.11o. New characteristic peaks at 35.3o, 38.5o, 49o, and 63o were noticed owing to the presence of NiO blended with chitosan nanoparticles. The estimated values of optical band gap energy for chitosan nanoparticles and chitosan/NiO nanocomposite are (3.6 eV, 3.5 eV), respectively. The photocatalytic degradation of MB dye employing chitosan nanoparticles and chitosan/NiO nanocomposite achieved 21 % and 96.1 %, respectively. The enhancement of photocatalytic efficiency of MB dye was mainly attributed to the potential effect of NiO nanoparticles. The findings also demonstrated that the photocatalytic performance of both chitosan nanoparticles and chitosan/NiO nanocomposite was pH, time, and catalyst doses dependent and obey Langmuir-Hinshelwood model. The photocatalytic activity of chitosan/NiO nanocomposite lost 14.9 % of its performance after first two cycles. Therefore, chitosan/NiO nanocomposite has emerged as a pioneering agent in sustainable water treatment, promising a transformative approach to combat water pollution. This study can guide future research, industry practices, and policy decisions towards a future where water treatment is synonymous with environmental harmony and innovation.

Monoclinic α-Bi2O3 nanorods by microwave-assisted synthesis: Photocatalytic and antioxidant properties

Nanotechnology has emerged as a new route for addressing most environmental and medical challenges, hence this field of research continues to generate research interest. Herein, Bi2O3 was synthesized by a microwave-assisted thermal process. X-ray diffraction (XRD) result confirmed that a nanocrystalline monoclinic crystal structure of the α-phase was formed, and both the Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analysis confirmed that the synthesized α-Bi2O3 were rod-like in shape. The length of the nanorods was in the range of 60–160 nm, with an average dimension of 101.5 nm, while the width has an average value of 23 nm. A band gap energy value of 2.75 eV was obtained from the absorption spectroscopy, and they absorbed light in the UV to visible range, with an absorption maximum of around 345 nm. Photocatalytic activity of the nanorods under UV irradiation was investigated by assessing the degradation of Bromocresol green (BG) as a model pollutant. The degradation process of the dye molecules was studied at different concentrations (20–80 mg/L), varied photocatalyst dosage (0.025, 0.05, 0.075, and 1.0 g), and a range of solution pH (3, 6, 9, and 12). About 75 % optimum photocatalytic efficiency was achieved at pH 6 after 3 h. In addition, the results showed that an increase in catalyst dosage and concentration of dye molecules contributed to promoting the degradation effect. Moreover, the photocatalyst was found to be stable after 4 consecutive cycles, with negligible loss of efficiency. The antioxidant potency of the nanorods was assessed by evaluating their free radical scavenging capabilities across 4 different assays: 1,1-diphenyl-2-picrylhydrazyle (DPPH), Nitric oxide (NO), Hydrogen peroxide (HP) radical inhibition, and Reducing power (RP). The results from the IC50 values indicated the sample exhibited better inhibition of HP (25.22 µg/mL), followed by RP (28.22 µg/mL), NO (29.37 µg/mL), and DPPH (32.72 µg/mL) respectively. However, the standard Ascorbic acid exhibited IC50 values of 16.25, 24.50, 25.07, and 28.40 µg/mL for DPPH, RP, HP, and NO, respectively. These unique properties of the nanorods showed that they have good antioxidant potential that is comparable with that of Ascorbic acid used as the standard.

Reaction Atmosphere-Controlled Thermal Conversion of Ferrocene to Hematite and Cementite Nanomaterials-Structural and Spectroscopic Investigations.

Recently, we have reported the influence of various reaction atmospheres on the solid-state reaction kinetics of ferrocene, where oxalic acid dihydrate was used as a coprecursor. In this light, present study discusses on the nature of decomposed materials of the solid-state reactions of ferrocene in O2, air, and N2 atmospheres. The ambient and oxidative atmospheres caused the decomposition to yield pure hematite nanomaterials, whereas cementite nanomaterials along with α-Fe were obtained in N2 atmosphere. The obtained materials were mostly agglomerated. Elemental composition of each material was estimated. Using the absorbance data, the energy band gap values were estimated and the related electronic transitions from the observed absorption spectra were explored. Urbach energy was calculated for hematite, which described the role of defects in the decomposed materials. The nanostructures exhibited photoluminescence due to self-trapped states linked to their optical characteristics. Raman spectroscopy of hematite detected seven Raman modes, confirming the rhombohedral structure, whereas the D and G bands were visible in the Raman spectra for cementite. Thus, the reaction atmosphere significantly influenced the thermal decomposition of ferrocene and controls the type of nanomaterials obtained. Plausible reactions of the undergoing solid-state decomposition have been proposed.

Role of Bi3+ ion substitution on the piezocatalytic degradation performance of lead-free BaTi0·89Sn0·11O3 at low vibrational energy

Harnessing low ultrasonic vibration energy to initiate piezocatalytic-based reactions is increasingly becoming a significant focus due to the current environmental energy crisis. In this study, we report on the potential of heterovalent ion substitution in improving piezocatalytic degradation of Rhodamine B dye (RhB) under the application of low-power ultrasonic vibration. For this purpose, bismuth ions Bi3+ are substituted into the lead-free ferroelectric BaTi0·89Sn0·11O3 (BTSn11-xBi, x = 0, 0.02, 0.04) submicrocubes synthesized using sol-gel method. The structural, morphological, optical and piezocatalytic properties of the prepared materials appear to be significantly influenced by the substituting content. Compared to pure BTSn11 and BTSn11-0.04Bi, BTSn11-0.02Bi exhibits the lowest band gap energy value of 3.22 eV, the smallest particle size value of 283 nm, the strongest piezoelectric current of about 8 μA/cm2, and the lowest required applied field for piezoresponse force microscopy hysteresis loops. The degradation efficiency and the kinetic rate constant are substantially higher for BTSn11-0.02Bi, indicating its enhanced piezocatalytic efficiency. Total organic carbon (TOC) measurements revealed good RhB mineralization using BTSn11-xBi piezocatalysts. Furthermore, the BTSn11-0.02Bi sample demonstrates good reusability and stability by maintaining effective RhB dye degradation for five consecutive cycling tests. These findings suggest that the BTSn11-0.02Bi piezocatalytic system holds significant potential for environmental remediation applications.

Band-gap tuning in Mn-doped Er2Ti2O7: Insight from the experimental and theoretical approach

We report the studies of electronic and optical properties of Er2Ti2−xMnxO7 (x = 0, 0.1, & 0.2) through combined theoretical insights from density functional theory (DFT) calculations and experimental approaches, including ultraviolet-visible absorption, photoluminescence emission spectroscopy, and Raman spectroscopy. For quantitatively correct optical bandgaps through DFT calculations, we considered the LDA-1/2 technique for the exchange-correlation interactions. The energy bandgap values obtained using theoretical formulations are in close accordance with the experimental results. The bandgap value obtained using the LDA-1/2 approach indicates the insulated ground state of the Er2Ti2−xMnxO7 (x = 0, 0.1, & 0.2) system. The band gap value obtained experimentally reduces from 3.82 eV to 2.45 eV as the level of Mn doping increases from 0 to 0.2. This reduction in the experimental band gap is attributed to the fact that inclusion of Mn atoms into the crystal lattice alters the electronic structure of the system. Substituting the Mn atom introduces additional electronic states within the band structure, leading to a modification of the band gap. Crystallographic data indicates that inclusion of Mn reduces the Ti-O bond length as in indicated in the table which reduces to 1.939(0) Å for x = 0.2 from 1.947(0) Å for x = 0. This results in the reduction of the extent of hybridization between O-2p and Ti-3d states, thereby reducing the band gap.

Manganese addition effect on structural and physical properties of calcium borovanadate glasses

New calcium borovanadate glass containing manganese ions within the system x Mn2O3-(30-x) V2O5-50 B2O3-20 CaO has been elaborated* in this work using melt quench process. The primary objective of this research is to examine the influence of introducing Mn2O3 upon the various properties of the elaborated glass specimens including physical, thermal, structural, optical and magnetic properties. X-ray diffraction indicated that the samples prepared were amorphous. The variation in density and molar volume revealed that the structure of the glass matrix cross-links and becomes more compact with increasing Mn2O3 content, which is confirmed when the glass transition temperature is increased. Furthermore, in order to check the group constitution of our glasses, a structural study was carried out using infrared (FTIR) and Raman spectroscopy. The optical characteristics of our vitreous materials were analyzed by UV solid, and the results of the band gap energy and refractive index values revealed an enhancement of non-bridging oxygen atoms (NBOs) with rising Mn2O3 concentration, also suggests that manganese acts as a structure modifier. The low Urbach energy values are an indication that the structure of our glasses is stable and uniform. The magnetic investigation highlighted the presence of the predominant antiferromagnetic order in the glass samples studied, which becomes stronger with the incorporation of more manganese ions into the structure.

Crystal structures and photoluminescence properties of undoped and Fe3+ doped Li2Ba3(P2O7)2 pyrophosphate nanopowders

Undoped and Fe3+ doped Li2Ba3(P2O7)2 pyrophosphate nanopowders were produced by a solid-state reaction process. The prepared samples underwent characterizations using XRD, SEM with EDS, HR-TEM with SAED, FTIR, Raman, UV-Vis, EPR and PL techniques. The XRD analysis confirms the orthorhombic crystal structure of the prepared samples and unit cell parameters were evaluated. The samples exhibited stone-like structures with low aggregation based on the micrographs obtained from SEM and HR-TEM images. Additionally, the grain and particle sizes of the powder samples were evaluated. The elements Li, O, P, Ba and Fe were confirmed to be present in the produced samples by EDS spectra. FT-IR and Raman spectral investigation revealed the fundamental vibrational and bending modes of various phosphate groups. The energy bands, identified as characteristic bands of Fe3+ ions, were produced in the UV–visible region of the optical absorption spectrum for the doped sample. The crystal field and inter-electronic parameters (Dq = 915, B = 700 and C = 2715 cm−1) were also evaluated. Furthermore, the refractive index and metallization criteria properties were calculated using energy bandgap values of 4.46 and 4.38 eV of the produced samples. The doping of Fe3+ ions led to a reduction in the bandgap energy, resulting in a red-shift. A resonance signal was observed in the EPR spectrum at g = 2.05, which can be ascribed to iron ions entering the host lattice at a distorted octahedral symmetry sites and this was also supported by optical absorption studies. The produced sample showed emission peaks at 354, 440 and 530 nm in the ultraviolet, blue and green regions of its photoluminescence spectrum. Photometric parameters, such as CCT, CRI and CIE chromatic coordinates, reveal that the prepared samples could bee used in LEDs applications. This work offers novel visions into diphosphate compounds doped with transition metal ions.

Analysis of effect of annealing at high temperature on nickel oxide and zinc oxide thin film for solar cell applications

The use of thin films in solar cell technology has gained substantial interest because of their potential for cost-effective and efficient energy conversion. nickel oxide (NiO) and zinc oxide (ZnO) have been used as potential materials in solar cells application especially third generation solar cells because of their good characteristics, such as high electrical conductivity, chemical stability, resistance to degradation, and abundance and low cost. However, at high temperatures, both NiO and ZnO can undergo thermal decomposition and exhibit crystal defects and grain boundaries. This work investigates high temperature annealing on the morphology, structural, and optical properties of NiO and ZnO thin films. The deposited material was annealed at 500 ℃, 600 ℃, and 700 ℃ and be characterized via scanning electron microscopy (SEM), XRD, and UV-Vi’s spectroscopy. The results showed that inceasing the annealing temperature can improve both ZnO and NiO thin films in structure and appearance. For ZnO, higher temperatures made the grains bigger and more orderly, and for NiO, the process made the grains more organized, bigger in size, and spread out more evenly. However, annealing at high temperature yields a smaller bandgap energy value for both thin films.

Facile green synthesis of Zn doped MoO3 nanoparticles and its photocatalytic and photoluminescence studies

In the field of nanoscience, the use of plant components for the synthesis of nanoparticles (NPs) is currently gaining popularity and has several advantages over physicochemical methods. Murraya koenigii (MK) leaf powder was used as the green fuel in the effective synthesis of the Zinc-doped molybdenum trioxide (Zn-MoO3) NPs by the green combustion method. The green synthesized NPs were characterized using XRD, FTIR, SEM, EDAX, UV–Vis and Photoluminescence (PL) spectroscopy techniques. The XRD pattern revealed the presence of an orthorhombic phase. The Tauc relation was used to calculate the energy band gap value of the samples found to be between 2.9 and 3.1 eV. The prepared NPs emit cyan light. Latent fingerprint analysis has revealed more distinct patterns in the near UV region (365 nm) and is useful in forensic investigations. The Rose Bengal (RB) dye degradation experiments are carried out under UV light exposure. Zn-MoO3 NPs have greater degradation efficiency than pure MoO3 NPs. Up to 99 % dye degradation is achieved in 150 min. After 3 photocatalysis cycles, the recycling test detects only an 8% decrease in photocatalyst efficiency. The obtained results proved that Zn-doped MoO3 NPs are the most suitable photocatalyst for RB degradation.

Melt-quenched zinc sodium borate glasses: Understanding the role of ZnO/Na2O ratio in density, band gap, and radiation attenuation

In this work, we successfully prepared glasses with the composition 55 B2O3 – (45-x) ZnO – x Na2O (x = 0, 5, 10, 15) using the traditional melt quenching procedure. We analyzed the influence of substituting ZnO with Na2O at different concentrations on the attenuation of ionizing radiation and the glass density. Different analytical tools, such as XRD, FTIR, and UV-VIS spectroscopy, were used to investigate the crystal structure and optical features of the produced samples. The partial replacement of ZnO by Na2O significantly reduces the density (from 3.36 to 2.87 g/cm3) and, in contrast, increases the molar volume of the glass (from 22.32 to 25.06 cm3/mol). The positions of the main peaks in the FTIR spectra remain relatively unchanged with increasing Na₂O content. The Fermi energy (EF) of the glasses increases from 3.16 to 3.45 eV with increasing Na2O concentration. Samples with higher Na2O exhibit a blue shift in the UV cutoff. The direct and indirect optical band gap energy values (Ed/Ein) increase from 3.42 to 3.62 eV and 2.87–3.23 eV, respectively, with increasing Na2O concentration. The radiation attenuation performance of these glass samples was examined through evaluation of various parameters like linear and mass attenuation coefficients (LAC/MAC), effective atomic number (Zeff), and half-value layer (HVL) and tenth-value layer (TVL) in the photon energy range of 10 keV–15 MeV. LAC and MAC values decrease with decreasing ZnO content. The two buildup factors, energy (EBF), and energy absorption (EABF) have been recorded for the different compositions at penetration depths up to 40 mean free paths. Samples with the highest ZnO concentration show the lowest HVL and TVL values at the lowest photon energy (≤2 MeV). Increasing Na2O concentration significantly increases both EBF and EABF, with their maxima occurring at 5 MeV. Increasing zinc oxide in the glass improves its radiation shielding ability, suggesting potential applications for zinc alkali borate glasses in radiation protection.

Synthesis and growth of organic 2-ethylimidazolium hydrogen diglycolate single crystal for nonlinear optical applications

A single crystal of 2-Ethylimidazolium hydrogen diglycolate (DAEI) has been grown by slow evaporation solution (SEST) technique at 35 °C. The DAEI crystal belongs to a monoclinic crystal system with a P21/c space group. The Hirshfeld surface analysis determined the grown crystal has the highest intermolecular contribution for O..H interaction. The phase purity and various planes (hkl) of the DAEI crystal system were determined by powder X-ray diffraction analysis (PXRD). The functional groups and their different vibrations of DAEI crystal were identified by Fourier transform infrared analysis. The band gap energy value of the DAEI crystal is found to be 5.32 eV. Photoluminescence measurement reveals that the DAEI crystal has green emission. The material shows major weight losses of around 82.45 % in the temperature between 140 °C and 300 °C. The dielectric analyses were carried out for different frequencies (1Hz–1MHz) and different temperatures. The third-order nonlinear optical properties such as refractive index (n2), absorption coefficient (β) and susceptibility (χ(3)) were determined using the Z-scan technique using a He–Ne laser (λ = 632.8 nm).

Regulation of photoelectric properties of multi-element (Sn, Fe, Ce) co-doped anatase TiO2: The first principles study

The energy band structure, density of states and optical properties of multi-element (Sn, Fe, Ce) co-doped anatase titanium dioxide have been calculated using the first principles method. The results show that two-element (Sn, Fe, Ce) doping affects the energy band structure more than the single doping behaviour. Co-doping of two of the three elements (Sn, Fe, Ce) reduced the energy band gap values of TiO2 compared to pure anatase TiO2.The forbidden bandwidths of Sn and Ce were smaller than those of mono-doped Sn, but the co-doped system had higher bandwidth narrowing than that of the mono-doped system. The co-doping of Sn and Ce is 0.206 eV smaller than the single doping of Sn, and the co-doping of Sn and Fe is 0.56 eV smaller than the single doping of Sn. The utilization of the regional light absorption is increased, and the absorption spectra are red-shifted. It can be seen that the co-doping method is more favourable to the improvement of visible light response and visible photocatalytic activity of TiO2 than the single doping method.

Production and Characterization of Electrodeposited Cadmium Sulfide Semiconductor Films with Different Boron Content

AbstractIn this study, Cadmium Sulfide (CdS) semiconductor films are electrodeposited on Indium Tin Oxide (ITO) substrates at 80 °C base temperature for different boric acid (H3BO3) ratios. The effect of boric acid on these films is investigated. For this, first of all, the structural change of the films is examined. Among the films obtained with different boric acid ratios, the optimum film is achieved with 0.06 m boric acid doped. From the basic absorption spectra (αhʋ) of the obtained CdS:B films, the variation of hʋ is drawn and it is determined that the CdS:B semiconductor films has a direct band transition. From the basic absorption spectra of the obtained CdS:B films, it is observed that the CdS:B semiconductor films has a direct band transition. In addition, the optical energy bandgap values obtained are in agreement with the values in the available literatures. The results of the structural, optical, and morphological properties of the films produced in this study indicate that among the selected additive ratios, 1% boric acid gives the best and optimum deposition condition. The thin films obtained are also found to be useful as absorber layers in photovoltaic solar cells.

The photodiode performances of NDI-appended ruthenium complexes

Abstract The synthesis and investigation of photoelectric studies of simple organic compounds as organic interlayers are of significant importance and widely studied. As such, we synthesized naphthalene diimide (NDI)-appended ruthenium complexes (Ru-NDIs) to function as the interface layer, and have fabricated novel Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) to investigate their photoelectric properties. Subsequently, we compared and discussed the photoelectric properties of these devices after synthesis and fabrication. According to this, the band-gap energy (E g ) values of organic materials were found to range from 2.95 eV to 3.14 eV, making them ideal for solar cells applications. Additionally, the photoresponse (Pr) values of Al/NDIs or Ru-NDIs/p-Si devices (D1-D4) were found to be 59.25, 1593.08, 198.77, and 134.47, respectively. Moreover, the Al/Ru-NDIs/p-Si D2 structure exhibited the highest Pr values. Experimental results indicate that since the four optoelectronic devices arranged with the derivation of synthesized compounds have good photoresponse characteristics, they can be utilized as a photosensor or photodiodes in different electronic and optoelectronic technologies.

Off-On-Off Cascade Recognition of Cyanide, Mercury, and Aluminum Using N/5-Monosubstituted Rhodanines.

This study aims to synthesize N- and 5-monosubstituted rhodanine derivatives as ion-sensing organics and investigate their sensing abilities. Following an easy and green approach to synthesis, the anion-sensing properties of the rhodanines were studied using colorimetric detection and spectroscopic methods. As a result of studies, rhodanines are found to be highly solvent-controlled colorimetric and fluorescent cyanide, mercury, and aluminum sensors. The stoichiometry of the interaction between CN- and both probes was determined to be 1:1 using Job's plot analysis. The binding constants (Ks) of CN- to 5-arylRh and N-arylRh were calculated to be 3.25 × 104 and 7.07 × 104 M-1, respectively, demonstrating their high affinity for cyanide ions. The limits of detections for the 5-arylRh and N-arylRh were also determined as 356 and 617 nM, respectively. In addition to detecting CN-, 5-arylRh also serves as a specific turn-off sensor for mercury and aluminum when cyanide and hydroxide are present. This enables the fluorescence intensity to be toggled on/off by alternating the addition of CN-/OH- and Hg2+/Al3+. Furthermore, the LOD values for Hg2+ and Al3+ with 5-arylRh-CN- and 5-arylRh-OH- were determined to be 414 nM and 1.35 μM, respectively. Furthermore, the turn-on binding mechanisms of 5-arylRh and N-arylRh with cyanide ions were elucidated, and the experimental band gap (highest occupied molecular orbital/least unoccupied molecular orbital) energy values corroborated the proposed mechanism. Additionally, the interaction mechanism of the probes with CN- was further investigated by using the 1H NMR technique. Collectively, these findings suggest that 5-arylRh, N-arylRh, and 5-arylRh-CN- hold promise as selective and sensitive candidate sensors for CN-, Hg2+, and Al3+ ions.

Synthesis, Spectral Characterization and Photoluminescence of 3-chloro-6-methoxy-2-(methylsulfanyl)quinoxaline in Different Solvents: An Experimental and Theoretical Investigation Using DFT.

In the present work, we synthesized 3-chloro-6-methoxy-2-(methyl sulfanyl) quinoxaline (3MSQ) using a microwave-assisted synthesis method. The physicochemical structural analysis of the synthesized compound utilizing 1H-NMR, 13C-NMR, and FT-IR spectroscopy techniques. The photophysical properties of 3MSQ was examined through absorption and fluorescence spectroscopy. Spectroscopic analyses revealed a bathochromic shift in both absorption and fluorescence spectra, attributed to the π → π* transition. Ground and excited state dipole moments was experimentally determined using the solvatochromic shift method, employing various correlations such as Lippert's, Bakhshiev's, Kawski-Chamma-Viallet's equations, and solvent polarity parameters. Our findings indicate that the excited state dipole moments exceed those of the ground state, suggesting increased polarity in the excited state. Further, the while detailed bond length, bond angles, dihedral angles, Mulliken charge distribution, ground state dipole moments and HOMO-LUMO energy gap estimated through ab initio computations using Gaussian-09W. The value of energy band gap obtained from both the methods are in good agreement. Furthermore, employing DFT computational analysis, we identified reactive centers such as electrophilic and nucleophilic sites using molecular electrostatic potential (MESP) 3D plots. Additionally, CIE chromaticity analysis was performed to understand the photoluminescent properties of 3MSQ. The insights derived from these analyses contribute to a better understanding of the molecule's electronic structure, photophysical properties, and solute-solvent interactions, thus providing valuable information regarding its behaviour and characteristics under diverse conditions. These results contribute to a comprehensive understanding of the molecular structure and properties of 3-chloro-6-methoxy-2-(methyl sulfanyl) quinoxaline (3MSQ).

Photocatalytic activity in graded off-valent cations substituted NaNbO3

This study investigates the impact of off-valent doping on the photocatalytic properties of NaNbO3 concerning the degradation of Methylene Blue. Compositions with x values of 0.00 (representing pure NaNbO3, denoted as NBO) and 0.05 within the material system Na1-xAxNbO3 (where A is K1+, Ba2+, La3+, abbreviated as K-NBO, Ba-NBO, and La-NBO respectively) were synthesized using the conventional solid-state reaction method. The UV–visible analysis revealed a decrease in the band gap for samples K-NBO and Ba-NBO, while an increase was observed for sample La-NBO. Raman modes of lower wave numbers merged and shifted towards the higher wave number side. The determination of valence band edge and conduction band edge involved computational analysis based on XPS survey scans, and the band gap energy values were derived from UV–Visible spectroscopy results. Examining the band diagram of the samples (NBO, K-NBO, Ba-NBO, and La-NBO) in conjunction with the highest occupied molecular orbital and lowest unoccupied molecular orbital levels of MB dye provided insights into potential degradation mechanisms. Photocatalytic dye degradation experiments for Methylene Blue demonstrated that doping increased the degradation efficiency of samples K-NBO, Ba-NBO, and La-NBO compared to NBO. Among all NaNbO3 based prepared samples, Ba-NBO exhibited the highest degradation efficiency of 96%, however slightly less than the reference sample P25 TiO2.

Synthesis of nano-crystalline K2NiF4-type phases La1+xSr1-xCoO4 (x = 0.0, 0.2, and 0.5): Effect of mixed valence state of Co on structural, magnetic and photocatalytic properties

A lot of work has already been reported on bulk K2NiF4-type layered perovskite oxides but hardly is known about their nano-crystalline state as they are generally prepared at high temperatures. In this connection, we have synthesized nanocrystalline La1+xSr1-xCoO4 layered perovskites oxides via sol-gel Pechini method. Efforts were also done to synthesize phases with x > 0.5 but remained unsuccessful. The Rietveld refinement investigation has confirmed the successful formation of single-phase compounds that crystallize in the I4/mmm space group with tetragonal symmetry. The X-ray photoelectron spectroscopy (XPS) analysis revealed that Co in La1+xSr1-xCoO4 has mixed valence states of +2 and + 3. Dominant anti-ferromagnetic (AFM) super-exchange Co2+―O―Co2+ and Co3+―O―Co3+ interactions were observed in all the synthesized nanophases and the existence of weak ferromagnetic (FM) interactions due to the generation of double-exchange Co2+―O―Co3+ interaction because of mixed valent state of Co. The increase in Néel temperature (TN) values with La doping has been attributed by the increased prevalence of anti-ferromagnetic (AFM) super-exchange Co2+―O―Co2+ and Co3+―O―Co3+ interactions. The band gap energy values (Eg) for all the prepared nano samples vary from 1.57 to 1.64 eV, rendering them highly competent catalysts for degradation of dyes. Additionally, the photocatalytic performance of the prepared nano photocatalysts was evaluated using cationic (MB & RhB) and anionic (MO) dye contaminants as well as their ternary mixture. LaSrCoO4 photocatalyst has been found to efficiently and swiftly degrade all three dye pollutants separately as well as in mixtures, with outstanding recyclability and durability. It has been observed that the x = 0.0 photocatalyst showed best degradation efficacy for RhB dye, i.e., ∼99 % in 100 min, compared to ∼91 % and ∼84 % for the x = 0.2 and 0.5 photocatalysts in the same time interval, respectively. These results suggest that LaSrCoO4 nano powder can be considered a promising photocatalyst in the dyes degradation.

Lanthanum and Indium intermetallics nanomaterial for thermal photovoltaic applications – A full potential study

In this work Full Potential study performed on Lanthanum compounds to analyze its photovoltaic properties. Five different combinations of Lanthanum and Indium with phosphorus are chosen in this study are La3P, La2InP, LaIn2P, LaP and InP. The optical, structural, thermoelectric, thermal, and electronic properties of all the above-mentioned compounds are analyzed using Density Functional Theory (DFT) applied in the WIEN2k software. Based on the analysis of electronic properties is concluded that La3P, LaP, La2InP and LaIn2P are conductors whereas InP is semiconductor (direct band gap) with band gap (energy) value 0.39 eV. The optical properties analysis shows these materials have desirable properties in the near UV or in the UV region. The low value of Gibbs energy indicates high thermodynamic stability. Power factor values for La2InP, LaP, InP and La3P are found to be in agreement with existing thermoelectric material, rendering them as potential thermal photovoltaic materials.