Band Gap Energy Values Research Articles

Synthesis of ZnO-TiO2 Nanoparticles by Sol-Gel Process and its Application for Solar Cell Semiconductor

ZnO-TiO2 semiconductor can be used in Dye-Sensitized Solar Cell (DSSC) devices as an alternative to renewable energy. This semiconductor can be synthesized by sol-gel method. The objective of this study is synthesizing the TiO2-doped ZnO nanoparticle semiconductors for DSSC devices with mangosteen peel extract dye. Avocado seeds were extracted with water, as a capping agent in the synthesis of ZnO-TiO2 (TiO2 ratio of 0,3,5,7 and 10% to ZnO). XRD results show the success of ZnO-TiO2 doping, due to the 2θ shift and changes in the crystal lattice. The average crystal size obtained was 33.7972 nm. The SEM results showed that the particle size of ZnO ranged from 45-100 nm. The UV-Vis dye measurements of mangosteen peel extract showed an absorption peak at 296-483 nm wavelength, with a corresponding band gap energy value of 3.04 eV. The UV-Vis DRS ZnO-TiO2 measurements have an average band gap energy of 3.1425 eV and ZnOof 3.1915 eV. The highest DSSC efficiency value is 2.15 x 10-2% at 7% ZnO-TiO2 semiconductor.

A novel nickel-doped photoactive nanocomposite materials for the application of wastewater treatment

We have reported an efficient and novel nanocomposite structure of nickel (0.5 %, 1.0 %, 1.5 %, 2.0 % and 2.5 %) doped Fe3O4@rGO which is prepared by a simple chemical co-precipitation technique for degradation of methylene blue. In the current study, reduced graphene oxide (rGO) is chosen as the electron mediator for NiFe3O4/rGO nanocomposite catalyst to construct a binary photocatalytic system. The analysis of structural and optical properties supports their nano size, formation of nanocomposite material, doping of nickel ions into the characteristic inverse spinel cubic structure of Fe3O4 and the existence of synergistic effect between NiFe3O4 and rGO. Methylene blue was considered as a model dye during the investigation of the Photocatalytic activity of NiFe3O4/rGO. From the kinetic measurements, the reaction rate was predicted to play a key role in the process of degradation. This discussion also highlights the absorption peak extension towards the visible region and the energy band gap value decreases with increasing the nickel dopant concentration in novel NiFe3O4/rGO nanocomposite material. Transition metal doping significantly enhances the degradation efficiency and reduces the recombination rate of charge carriers which makes the NiFe3O4/rGO nanocomposite material a potential candidate for the degradation of methylene blue from wastewater. As indicated by all the nanocomposites, photocatalytic activity was higher than the pure Fe3O4 photocatalyst, and the highest photodegradation of 96.3 % MB within 30 min irradiation under visible light was shown by the 2.0 % of nickel-doped Fe3O4@rGO. In addition, the study examined the photodegradation process and photocatalytic reaction kinetics of MB.

Exploring the comparison of optical, dielectric and photocatalytic performance of Yb3+ and Gd3+ half-doped DyCrO3 nanostructures

The auto combustion sol-gel method was utilized to prepare Dy0.5Gd0.5CrO3 (DGCO) and Dy0.5Yb0.5CrO3 (DYCO) nanomaterials. The single-phase formation of materials was confirmed with the X-ray diffraction technique. Utilizing Kubelka-Munk function, the optical bandgap energy values were found to be 3.39 eV (DGCO) and 2.61 eV (DYCO). The dielectric properties were analyzed in frequency range from 10 kHz to 2 MHz and a temperature range from 25 °C to 225 °C. The conduction mechanism followed the universal Jonscher's power law, which revealed that conduction process was primarily governed by the small polaron hopping. The CBH, NSPT, and QMT models were applicable for the a.c. conduction in the DGCO nanomaterial whereas the CBH and NSPT models were more appropriate for the DYCO nanomaterial. The Kohlrausch, Williams and Watts function was used to correlate the imaginary electrical modulus spectrum, which confirmed that the relaxation process in the materials was non Debye-type. An impedance spectroscopic measurement revealed the influence of grain and grain boundaries and it followed negative temperature coefficient resistance behaviour at higher temperatures. Both DGCO and DYCO nanomaterials were also investigated for their photocatalytic degradation of Rhodamine B (RhB) and Methylene Blue (MB) dyes. The degradation, under direct solar irradiation, was 84 % (RhB) and 63 % (MB) for DYCO nanomaterial and 54 % (RhB) and 44 % (MB) for DGCO nanomaterial, indicating their potential in water treatment.

Formation, Enhanced Crystallization, Optical Absorption and Electrical Conduction in Copper Indium Selenide Thin Films Prepared via Pulse Laser Welding Technique

AbstractIn this study, thin films of CuInSe2 (CIS) are expeditiously fabricated within 1 s utilizing the pulsed laser welding (PLW) technique. Preceding the PLW process, thin films of InSe (500 nm) are coated with Cu nanosheets of 60 and 120 nm thicknesses using vacuum coating systems. The optimal PLW parameters leading to the formation of CIS films include a pulse width of 1.0 ms, a spot diameter of 2.0 mm, and a repetition frequency of 10 Hz. The resulting CIS films exhibited a well‐crystalline cubic structure with lattice parameters of 5.265 Å. Surface morphology analyses revealed the preferential formation of porous films with varying stoichiometry, a characteristic that can be manipulated by adjusting laser welding parameters. The energy band gap and room temperature electrical conductivity display values of 1.80 eV and 2.06 × 10−5 (Ωcm)−1, respectively. Cu‐rich samples exhibit a wider energy band gap of 1.94 eV and lower electrical conductivity values of 4.78 × 10−7 (Ωcm)−1. The CIS film demonstrates n‐type conductivity attributed to the formation of donor levels centered at 0.24 and 0.10 eV. This study presents an ultrafast method for fabricating CIS films with physical properties compatible with those produced using traditional methods.

Phyto-fabrication of CuO–Co3O4 nanocomposites for antibacterial, photocatalytic and antioxidant evaluations: An in-vitro investigation

In this current investigation, we elucidated the microwave-assisted green synthesis of 90:10, 80:20, and 70:30 CuO–Co3O4 nanocomposites (NCs) from Ipomoea carnea leaf extract, manifesting their remarkable antibacterial, photocatalytic, and antioxidant capabilities. The spectroscopic techniques of XRD, SEM, EDX, TEM, FTIR, and UV–visible spectroscopy were employed to validate the formation of the synthesized NCs. SEM and TEM images revealed distinctive snowball-rod and distorted spherical structures in the synthesized nanocomposites, with average particle sizes of 33.36, 26.17, and 29.10 nm. The estimated energy band gap values were 1.20, 1.40, and 1.50 eV for the respective nanocomposites. The well diffusion method was utilized to explore the zone of inhibition (ZOI) against bacteria, namely Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The nanocomposites, specifically the 90:10 and 80:20 CuO–Co3O4 blends, exhibited a noteworthy Zone of Inhibition (ZOI) during testing against B. subtilis, with approximate values of 34.76 ± 0.23 and 33.33 ± 0.32 mm, respectively. Furthermore, the photocatalytic potential has been investigated against the dyes Malachite green (MG) and Congo red (CR). Notably, the 90:10 NCs displayed an exceptional photodegradation rate of 97.69 % for MG and 95 % for CR within a mere 45 min. Moreover, the 70:30 NCs exhibited a commendable radical scavenging activity of approximately 97.53 % at a concentration of 800 μg/mL, while ascorbic acid, used as a standard, displayed a scavenging activity of 98.63 %. These investigations unveil the environmentally friendly, innovative, and cost-effective attributes of CuO–Co3O4 NCs derived from Ipomoea carnea leaf extract, which demonstrated excellent antibacterial, photocatalytic, and antioxidant properties.

Combustion-synthesized ZnO-CeO2 heterojunctions for advanced photocatalytic dye degradation

ZnO-CeO2 heterojunctions were successfully synthesized utilizing a simple combustion approach employing equimolar solutions of the precursor chemicals. The morphology, content, crystallinity, purity, crystal size and bandgap energy features of the synthesized heterojunctions were carefully investigated utilizing various analytical methods. FESEM investigation indicated a heterogeneous flake or sheet-like appearance, as well as a rough and granular surface for the heterojunctions. XRD study found that the average crystallite size for ZnO-CeO2 heterojunctions was 5.38 nm. The absorbance spectrum showed a peak absorption at 372 nm and a band gap energy value of 2.1 eV. The photocatalytic activity of the synthesized ZnO-CeO2 heterojunctions towards three model dyes, CR, RhB, and MB dyes, were investigated. Percent degradations of 96.61 % and 98.11 %, respectively were achieved for CR and MB dyes within 30 min, while 98.25 % photodegradation was observed for RhB dye within 60 min of UV irradiation. The rapid degradation of CR and MB dyes suggests their high susceptibility to the photocatalytic action of ZnO-CeO2 heterojunctions as compared to RhB dye. Kinetic analysis indicated that the degradation of dyes followed a pseudo-first-order kinetic model. Finally, for the photocatalytic activity of the as-synthesized heterojunctions, a photodegradation mechanism was also postulated.

Sustainable fabrication of biogenic Fe–Zn nano core-shell and their photocatalytic efficiency against third generation antibiotics

The photocatalysis of third generation antibiotics was deliberated using biogenic iron oxide (FeO NPs) and iron-zinc (Fe–Zn) nano core-shell. Photocatalysts were prepared from aqueous extract of Adiantum incisum (Ai) by reacting with apposite salt solutions. FeO NPs were synthesized by mixing 5 % Ai extract with 5 mM FeSO4.7H2O at alkaline pH (50 °C). While Fe–Zn nano core-shell were synthesized by coating ZnO NPs on FeO NPs using successive reduction method. Synthesis and stabilization of nanoparticles were substantiated by diverse surface plasmonic resonance peak of FeO NPs and Fe–Zn nano core-shell at explicit wavelength ranges. Band gap energy values, Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD), Raman and Scanning Electron Microscope (SEM) analysis validates that coating was done efficaciously. Fourier Transform Infrared Spectroscopy (FTIR) recognized the role of plant phytochemicals in NPs reduction and stabilization. SEM-Energy Dispersive X-Ray analysis (EDX) analysis unveiled that FeO NPs and core-shell aggregates are orbicular in shape. Average crystalline size of FeO NPs and Fe–Zn nano core-shell obtained from XRD was 15.64 nm and 22.94 nm respectively. The photocatalytic degradation of Ampicillin, Levofloxacin and Ceftriaxone under UV and Sunlight displayed that Fe–Zn nano core-shell have high degradation capability than FeO NPs. Degradation potential was higher in UV than in sunlight. Maximum degradation of Ampicillin (74.4 %) was attained under UV light and (60.31 %) in sunlight followed by Levofloxacin. Degradation was further confirmed by conducting FTIR analysis and antimicrobial studies. Gas Chromatography-Mass Spectrometry detected Hexadecenoic acid as the main degradation product in nano treated Ampicillin and Levofloxacin.

Impact of Cu2+ doping on the structural and optical properties of LaFeO3 nanoparticles for optoelectronic applications

We investigate the structural, linear and nonlinear optical properties of LaFe1-xCuxO3 (x = 0, 0.05, and 0.1) nanoparticles using XRD, SEM, and UV–visible spectroscopy techniques. The sol-gel technique was utilized to prepare the studied nanoparticles. The structural study shows that all compounds crystallize in the orthorhombic structure with the Pnma space group. The optical constants and parameters such as refractive index, extinction coefficient and dielectric constants were determined from the absorbance, transmission and reflectance. The refractive index (n) and extinction coefficient (k) were found to increase with increasing Cu content. As the Cu concentration increases from 0 to 0.1, the band gap energy (Eg) values were found to increase from 2.389 to 2.44 eV, while the Urbach energy (Eu) decreases from 0.42 eV to 0.312 eV. The single oscillator energy (E0) values were found to increase from 5.80 eV to 6.001 eV with increasing Cu content, as well as the dispersion energy (Ed) increases from 16.11 eV to 22.12 eV. For these samples, the nonlinear optical susceptibility (χ(3)) and nonlinear refractive index were determined to be between 1.3898 × 10−12 esu and 3.2906 × 10−12esu and 26.9436 × 10−12 - 57.2780 × 10−12esu respectively. These calculated parameters show also an increasing trend with Cu doping content.

Enhancement of the Optical properties of Mg0.6 Cu0.4 FeCrO4 spinel ferrite via heat treatment

We conducted a study to analyze the structural, morphological, and optical properties of Mg0.6Cu0.4FeCrO4 spinel ferrite samples synthesized by the sol-gel method and sintered at two different temperatures, 900 °C and 1100 °C. The infrared spectrum analysis revealed the presence of only the tetrahedral stretch band (νA), which had frequencies of 585 cm−1 for 900 °C and 586 cm−1 for 1100 °C. The bandgap energy and Urbach energy values decrease with increasing sintering temperature. The bandgap energy decreases from 1.20 eV to 1.06 eV, while the Urbach energy values decrease from 1.26 eV to 1.11 eV. Emphasis has been placed on the analysis of key aspects such as refractive index(n), optical conductivity (σopt), extinction coefficient (k), penetration depth (ẟ), dielectric tangent loss, Q-factor, and dielectric constant. Optical studies have provided confirmation that Mg0.6Cu0.4FeCrO4 spinel ferrites exhibit properties suitable for optoelectronics applications.

Effect of the inclusion of Fe2O3 on the optical and electrical transport properties into sodium-zinc-phosphate quaternary glassy systems

Glass systems, xFe2O3–(35-x)Na2O–25ZnO–40P2O5) (x = 10, 15, 20, and 25 mol%), were prepared using the melt-quenching technique. FTIR analysis revealed stretching vibrations of the P–O–P and P–O bonds and XRD investigation revealed a pure amorphous structure. It was discovered that with rising Fe2O3 content (x), the values of density increased, but the values of molar volume decreased. The Fe2O3 incorporation into the glass matrix resulted in decrement in the optical band gap energy (Eopt) value from 2.99 to 2.16 eV. The addition of Fe2O3 to the glass network reduced the quantity of non-bridging oxygen ions, improving the observed refractive index value. According to the Mott and Greaves model, the small polaron hopping model was responsible for the DC conductivity mechanism, and the density of states at the Fermi level increased as DC conductivity increased with increasing Fe2O3 content, but hopping distance (Rhop) and hopping energy (Whop) sharply decreased. It was concluded that the AC conductivity mechanism followed the correlated barrier hopping model as the power-law exponent (s) of Jonscher's universal power law decreased with temperature. AC conductivity increased with rising Fe2O3 concentration due to a decrement in the polaron hopping distance value and an increment in the concentration of defect pair states.

Processing and enhancement of thermoelectric performance of Nb doped ZnO (NZO) ceramics

In this investigation, we extensively studied the effect of various parameters on the processing, microstructure, sintering and thermoelectric characteristics of ZnO ceramics. Different Nb-doped ZnO-based ceramics, ranging from 0 to 0.25 wt %, were fabricated and sintered at the temperature of 1450 °C for 2 h in an inert atmosphere of argon (Ar). Various characterizations were employed to discern the performance attributes of these ceramics, encompassing phase analysis, densification, and microstructure evaluations. Thermal conductivity properties were studied from room temperature up to the temperature of 800 °C. Thermoelectric properties and efficiency of the sintered ceramics were evaluated across the temperature range of 100–800 °C. Results indicated that the incorporation of Nb into ZnO ceramics resulted in a harmonious structure due to the attained homogeneous and complete solid solution diffusion reaction. It was found that the optimal values for thermal conductivity, electrical resistivity, and thermoelectric properties were achieved at 0.15 wt % Nb doping. ZnO doped ceramics exhibited typical behavior of n-type semiconductors, showcasing exceptional thermoelectric properties at elevated temperatures. Our findings indicate that native defects, such as oxygen vacancies (OV), contribute to decreased band gap energy values and increased carrier concentration, thereby enhancing electrical conductivity and power factor. Hence, this study underscores the viability and practicality of Nb-doping ZnO sintered in an argon atmosphere as an effective approach to enhance its thermoelectric performance.

Influence of composition on luminescence properties of Cd1-xZnxWO4 solid solutions

A set of single-phase Cd1-xZnxWO4 (x = 0–1) solid solutions synthesized by spontaneous crystallization technique was studied by the methods of luminescence and electron paramagnetic resonance (EPR) spectroscopy. Luminescence spectra of all studied solutions are characterised by a single emission band related to the intrinsic emission of self-trapped excitons. The dependence of luminescence spectra and thermostimulated luminescence (TSL) curves on solution composition was investigated, and the origin of TSL peaks was analysed on the basis of the EPR data. It is shown that the values of optical bandgap and activation energy of luminescence thermal quenching gradually change with solution composition. Several phenomena are observed in solid solutions predominantly at intermediate concentrations of Cd and Zn cations that can be connected with the structural disorder of the solid solutions. In particular, the deviation of lattice parameters from the Vegard's law, the redshift and broadening of the emission band, the suppression of low-temperature (T < 80 K) TSL peaks related to self-trapped holes and the broadening of high-temperature (100–200 K) TSL peaks related to structural defects. The structural disorder arises due to the non-homogeneous distribution of substitutional atoms in cation lattice sites, pronounced because of the mismatch in ionic radii of substitutional cations, which reaches 28.3 % for Cd2+ and Zn2+.

In Situ Green Synthesis of Co3O4@ZnO Core-Shell Nanoparticles Using Datura stramonium Leaf Extract: Antibacterial and Antioxidant Studies

Investigating and synthesizing potent antibacterial NPs using biological methods is highly preferred, and it involves nontoxic, cost-effective, and environmentally friendly chemicals and methods. Antibiotic drug resistance and oxidative stress have become a serious public health issue worldwide. Hence, the key objective of this study was to biologically synthesize and characterize the potent antibacterial Co3O4@ZnO core-shell nanoparticles for the antibacterial application. The radical scavenging ability of green synthesized Co3O4@ZnO core-shell nanoparticles was also determined. In this study, Co3O4@ZnO core-shell nanoparticles (CZCS NPs) have been synthesized using three different core to shell materials ratios of Co3O4 to ZnO (0.5 : 0.25 CZCS (1), 0.5 : 0.5 CZCS (2), and 0.5 : 0.75 M CZCS (3)) by employing Datura stramonium leaf extract. The polycrystalline nature of Co3O4@ZnO core-shell nanoparticles was investigated using the XRD and SAED characterization techniques. The investigated nanostructure of Co3O4@ZnO core-shell nanoparticles appeared with Co3O4 as the core and ZnO as an outer shell. Additionally, a variety of physicochemical properties of the nanoparticles were determined using various characterization techniques. The average crystallite sizes of CZCS (1), CZCS (2), and CZCS (3) were found to be 24 ± 1.4 , 22 ± 1.5 , and 25 ± 1.5 nm, respectively. The band gap energy values for CZCS (1), CZCS (2), and CZCS (3) determined from the UV-DRS data were found to be 2.75, 2.76, and 2.73 eV, respectively. The high inhibition activities against S. aureus, S. pyogenes, E. coli, and P. aeruginosa bacterial strains were obtained for the small size CZCS (2) nanoparticles at the concentration of 100 mg/mL with 22 ± 0.34, 19 ± 0 . 32 , 18 ± 0.45 , and 17 ± 0 .32 mm values, respectively. The high inhibition performance of CZCS (2) nanoparticles against Gram-positive and Gram-negative bacteria which is even above the control drug ampicillin is because of its small size and synergistic effect. The percentage scavenging activity of Co3O4@ZnO core-shell nanoparticles was also studied and CZCS (2) nanoparticles showed a good scavenging capacity (86.87%) at 500 μg/mL with IC50 of 209.26 μg/mL.

Efficient photocatalysis of Zn1-2xEuxDyxO nanoparticles towards the degradation of hazardous Rhodamine B dye

Industrial waste is the principal source of highly toxic organic and heavy metals. Treating such effluence is highly required to provide a clean ecosystem for living organisms. Photocatalysis is one of the most efficient, economical, and time-efficient ways for the removal of industrial wastes. In the current search, we propose to prepare a series of Zn1-2xEuxDyxO samples (x = 0.00–0.05), using the simple sol-gel auto-combustion route. The XRD results indicated a hexagonal structure for all samples. The presence of europium and dysprosium elements and their successful doping into the ZnO were proved by XRD and EDX analyses. The mean crystallite size and the values of band gap energy were altered by the Eu and Dy doping. The photocatalytic action of Zn1-2xEuxDyxO samples was assessed for Rhodamine B degradation. The experiments indicated a degradation with an efficiency of 99.1%, 95.1%, and 97.4% for Zn0.98Eu0.01Dy0.01O, Zn0.94Eu0.03Dy0.03O, and Zn0.90Eu0.051Dy0.05O samples, respectively within 90 min. The Zn0.98Eu0.01Dy0.01O sample exhibited the maximum photocatalytic efficiency with an excellent rate constant (r = 0.054 min−1) among all samples. The obtained findings demonstrated that the Eu and Dy co-doping at a specific concentration is a useful way to reach an effective photocatalytic activity of ZnO nanoparticles.

Synthesis of sol-gel TiO2 nanoparticles and assessment of their antifungal activity for the eventual conservation of historical documents

One of the main causes of deterioration of ancient documents is the presence of microorganisms, especially fungi. In this study, we report on the detection of microbiological contamination in ancient books from the Franciscan Library of San Pedro Cholula, in the state of Puebla, Mexico. The microscopic observation of different organic pigments and in vitro assays indicated the presence of Rhizopus sp., Mucor sp., and Alternaria sp. on the papers. The fungicidal activity of TiO2 nanoparticles (NPs), synthesized by the sol gel process, was then evaluated against these strains by two different methods: i) the agar well diffusion method using Petri dishes and ii) in pieces of old book pages, where the strains had been previously incubated. From TEM measurements, it was determined that the TiO2 NPs had a diameter of 70 nm. Anatase TiO2 NPs were synthesized as indicated by Raman spectroscopy and XRD. From UV–Vis spectroscopy and the Tauc´s method for an indirect band-gap semiconductor, a band-gap energy value of 2.9 eV was obtained. The surface chemistry of the TiO2 NPs/paper substrates was analyzed by XPS. In addition, a core-level XPS analysis of the O 1s and C 1s orbitals was used to identify signals related to cellulose. The antifungal activity of TiO2 NPs was demonstrated for the investigated fungi. A higher inhibition occurred for Rhizopus sp., followed by Mucor sp., and Alternaria sp. with inhibition halos of 26, 24, and 18 % in diameter, respectively. This work used highly sensitive techniques with the aim of proposing methodologies that contribute to the preservation of historical documents.

Spectroscopic properties (FT-IR, NMR and UV) and DFT studies of amodiaquine

Amodiaquine (AQ) was synthesized by a condensation reaction and characterized by experimental FT-IR, 1H and 13C nuclear magnetic resonance (NMR) and UV spectroscopies. In the present work, Density Functional Theory (DFT) calculations using B3LYP method with 6–311++G(d,p) and 6–311++G(2d, p) basis sets were performed, first, to confirm its structure, then to explain its reactive nature through its molecular properties such as natural charges, local and global reactivity descriptors or natural bond orbital (NBO). The 1H and 13C NMR chemical shifts were calculated by using the gauge-independent atomic orbital (GIAO) method, while the electronic UV–Vis spectrum is predicted using the time-dependent density functional theory (TD-DFT). Globally, the computerized results showed close similarity with the experimental values.The calculated energy band gap (ELUMO-EHOMO) value of AQ was found to be 4.09 eV suggesting that it could be considered as a hard molecule with high stability, supported by global reactivity descriptors. Molecular electrostatic potential (MEP) analysis revealed heteroatoms (oxygen and nitrogen) as the most putative nucleophilic sites when hydrogen atoms to which they are linked appear as electrophilic sites. The potential use of amodiaquine as non-linear optical (NLO) material and its thermodynamic indicators have also been assessed.

Exploring the radiation shielding properties of B2O3-PbO-TeO2-CeO2-WO3 glasses: A comprehensive study on structural, mechanical, gamma, and neutron attenuation characteristics

The objective of this study is to develop radiation-shielding glass materials with excellent physical properties by incorporating varying amounts of WO3 (x = 1, 3, 5, 10, 20 mol%) into 45B2O3-(20-x)PbO–30TeO2–5CeO2-xWO3 glasses. The glasses were synthesized using the melt casting method with B2O3–PbO–TeO2–CeO2 powders. Experimental measurements and theoretical calculations were performed to determine the mass attenuation coefficients (MAC), mean free path (MFP), half value layer (HVL), and effective atomic numbers (Zeff) of the glasses within the energy range of 59.54–661.62 keV. Additionally, the structural and mechanical properties of the synthesized glasses were evaluated using XRD, UV–Vis, FT-IR, and Micro-Vickers hardness techniques. XRD analysis indicated that all glass compositions formed amorphous structure. The addition of WO3 caused a decrease in the optical band gap energy values of the glasses. Moreover, the incorporation of WO3 enhanced the elasticity of the glasses by 17–21%. The hardness and fracture toughness values were also improved with the addition of 5% WO3, increasing from 3.53 to 4.14 GPa and from 1.07 to 1.14 MPa m0.5, respectively. The radiation shielding properties assessed through proton and alpha shielding characteristics, revealed that the addition of 20% WO3 to the glass composition allowed approximations of 82.8% of the MAC values of the glass doped with 20% PbO. Overall, the findings indicate that incorporating WO3 as a dopant improves the glasses' elastic and mechanical properties enhancing their radiation shielding ability.

A study on the impact of [BO33−], [PO43−] and [SO42−] ions in normal cubic structures via structural and photoluminescence properties of Y2O3:Eu3+ phosphors

A series of Y2O3-AG: Eu3+ (where AG = Anionic Groups [PO43−, SO42− and BO33−]) nanophosphors were synthesized via a chemical combustion method and their structural and photoluminescence properties were investigated. The crystal structure and the surface morphology studies were analysed through the X-Ray powder diffraction (XRPD), Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The XRD results showed that undoped Y2O3 phosphors crystalized in a cubic crystal structure, while the Y2O3-AG phosphors transformed from the pure Y2O3 cubic structures, except for SO42− based phosphor materials. The SEM micrographs showed that the particles were formed in the micrometer range with different sizes and shapes. The FTIR spectra revealed the presence of various structural groups in the Y2O3, Y2O3-AG: Eu3+ phosphors. Moreover, the optical diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) properties were investigated. Using the DRS data, the optical band gap energy values were obtained from the Kubelka-Munk function theory. Upon 395 nm excitation, the Y2O3-AG: Eu3+ phosphors emitted red light at 615 nm wavelength. Among all the samples, the Y2O3-BO3: Eu3+ produced the highest intensity of red-light emission. The International Commission on Illumination color coordinates indicated that these phosphors are potential candidates for producing enhanced red color components in white light-emitting diode (W-LEDs) applications.

Synthesis and characterization of magnesium zinc ferrite nanoparticles for catalytic hydrogen evolution

We have prepared Mg1-xZnxFe2O4 nanoparticles (x values varying from 0.0 to 0.8 by 0.2 increments) for use as catalysts for hydrogen production in the methanolysis of sodium borohydride (NaBH4). The catalytic performance of the Mg1-xZnxFe2O4 nanoparticles with different zinc content for hydrogen production were evaluated in the methanolysis of NaBH4 inside glass vessels. Different characterization techniques were used to analyse the prepared nanoparticles such as X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM), Transmission Electron microscopy (TEM), and Scanning Transmission Electron microscopy STEM. The average size of Mg1-xZnxFe2O4 nanoparticles was 10 nm. The largest energy band gap value was 4.77 eV for MgFe2O4 nanoparticles, while the lowest value was 2.89 eV for Mg0.2Zn0.8Fe2O4 nanoparticles. Mg0.8Zn0.2Fe2O4 nanoparticles were proven as the catalysts with the highest hydrogeneration rate with a value of 15,957 mL min−1 g−1.

Synthesis of new oxygen deficient triple layered perovskite oxides LaSr3Fe3-xCrxO10-δ (x = 0.0, 0.2, and 0.5): Structural, optical, magnetic and photocatalytic properties

In the present study, new oxygen deficient triple layered Ruddlesden-Popper (RP) phases LaSr3Fe3-xCrxO10-δ (x = 0.0, 0.2, and 0.5) have been prepared via sol-gel procedure. The prepared n = 3 RP phases were characterized with various characterization techniques in order to visualize the effect of Cr3+ doping on structural, optical, magnetic and photocatalytic properties. Rietveld structural refinements showed that all the phases crystallized in the I4/mmm space group with tetragonal symmetry. Dominant anti-ferromagnetic (AFM) interactions (Fe3+―O―Fe3+ and Fe4+―O―Fe4+) were noticed in each of these oxygen deficient triple layered phases with presence of weak ferromagnetic (FM) interactions. The decline in the values of Neel temperature (TN) with Cr doping has been interpreted on the basis of increase in FM Fe3+―O―Cr3+ interactions. The energy band gap values (Eg) of all the synthesised oxygen deficient phases vary from 1.63 to 1.73 eV, which makes them excellent photocatalysts for dye decontamination. Furthermore, the photocatalytic performance of the prepared phases was assessed by utilizing rhodamine B (RhB) dye as model dye pollutant. It was found that LaSr3Fe2.5Cr0.5O9.17 photocatalyst showed excellent results in the removal of RhB dye. As a result, we were further encouraged to extend the degradation to some other organic dyes such as methylene blue (MB), methyl orange (MO) and their mixture (RhB + MB + MO).