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The ferrite series having formulation SrYbyFe2–yO4 (y = 0.00 to 0.10) were synthesized via the sol–gel procedure. The involvement of the yttrium in the base produces several changes in the structural, magnetic, and electrical performance of the system. Investigation of structural parameters was done through X-ray diffraction. All samples have cubic structures confirmed from X-ray diffraction. The coercivity of sample enlarges with the involvement of Yb-ions while their saturation and remanence magnetization values drop. When the concentration of Yb-ion increases in the lattice, the real and imaginary values of permittivity reduce. The increased content of Yb enhances the impedance value. The analysis of the M vs H loop was finished under the fixed range of –2 to +2 kOe. By using 0.5 to 12 GHz frequency, the microwave measurements of all the sample were performed. The dispersion of frequency of ferrites is responsible for the natural magnetic resonance phenomenon and the domain wall pinning. The evaluated features of synthesized sample shows their appropriation for microwave absorption appliances. more...

The influence of indium on the properties of Cu0.5Zn0.5Fe2O4 nano ferrites synthesized by sol–gel auto-combustion technique was studied. X-ray diffraction (XRD) analysis demonstrated that pure and substituted ferrites possessed cubic spinel structure. The lattice parameter increases with the inclusion of In3+ for x ≤ 0.16 and decreases subsequently. A linear decrease in crystallite size was found as concentration of indium increased. X-ray density, strain, and dislocation density were increased as indium content increases. Hopping lengths as well as radii of A and B sites revealed increasing behavior up to x = 0.16 and decreased thereafter. The spectral bands indicated the formation of spinel structure. The band positions were altered with the increase of In3+ contents. The inclusion of indium ions increases the value of dielectric parameters while magnetic parameters decreased. This increase in dielectric parameters and decrease in magnetization proposed that synthesized magnetic oxides may have potential in the fabrication of switching and high-frequency devices. more...

In the present work, the nanoparticles of spinel bismuth Chromites (BiCr2O4) are prepared using sol gel method. We have developed a novel technique to achieve longer stability and higher ionic storage of MXene/BiCr2O4nanocomposite by using co-precipitation method. Structural and morphological properties of the prepared nano-structures are thoroughly investigated. The band gap is seen to reduce from 2.08 eV for MXene to 1.90eV for MXene/BiCr2O4 nanocomposite which encompasses all the earlier stated values. The average particle size of nanocomposite MXene/BiCr2O4 is 11.15 nm. The EDX analysis is performed to confirm the elemental composition of the prepared nano-composites. Composite electrodes are then electro-polymerized on the coating of glassy carbon electrode. The value of specific capacitance is measured to be 455.0 F/g, suggesting the plausible usage of the synthesized material in super capacitance applications. The prepared MXene/BiCr2O4 nanocomposites can be used as efficient promoters and electrode materials, based on the attractive properties like reduced band gap, high electrochemical stability, and excellent value of specific capacitance. more...

Transition metal oxides have been explored in supercapacitor applications owing to their safety, low cost, high specific capacitance and high electrochemical activity. Among all transition metal oxides, zinc oxide based materials show remarkable response for designing the supercapacitors with high electrochemical activity. Here in, Mn doped ZnO (Zn1-xMnxO3 with x = 0, 0.25, 0.50, 0.75 and 1) was synthesized by a facile hydrothermal method. Doping of Mn into the ZnO increased the surface area and decease the charge transfer resistance for the Zn0.5Mn0.5O3. All the synthesized materials were characterized by x-ray diffraction (XRD), scanning electron microscopy SEM), BET, electrochemical tests and other various analytical techniques to confirm the structural, morphological, textural and suprcapacitive properties. The synthesized material Zn0.5Mn0.5O3 having the porous nanoribons structure with BET surface area (2490 cm2/g). The electrochemical studies showed significantly enhanced response toward pseudocapacitive nature. The synthesized material exhibited the excellent specific capacitance (515F/g), specific energy (28.61 Wh/kg) and specific power (1000 W/kg) at current density of 2 mA/g. Such impressive and superior properties make the MnZnO3 material as promising candidate for new generation supercapacitor applications. more...

Cadmium substituted Z-type hexaferrites are prepared via the sol-gel route. The phase temperature of pre-sintered materials is studied from the thermal analysis. The single-phase of Z-type hexaferrite is found through X-ray diffraction investigation. The Crystallite sizes of the entire samples are evaluated within the range of 14–15 nm. The Fe–O stretching vibration band at 566 cm−1 is confirmed from Fourier transform infrared spectroscopy. Saturation magnetization (Ms) coercivity (Hc) and remanence (Mr) is examined by a vibrating sample magnetometer. The magnitude of Ms has been increased from 45.41 to 56.35 emu/g with an increase of Cd2+ concentration. The magnitude of Hc increased from 950.79 to 2186.95 Oe with an increment of Cd2+ concentration. Small values of squareness ratio (less than 0.5) showed the hard and single magnetic domain nature of the materials. The dielectric properties were analyzed using an impedance analyzer. Dielectric parameters show an increasing trend with the substitution of Cd2+. The maximum values of quality factor up to 17,000 and 10,000 are observed for sample Ba2·85Cd0·15Co2Fe24O41 at 1 GHz and 2.7 GHz, respectively. The high value of the Q-factor shows that these ferrites can be applicable for the formation of resonant circuits and multilayer chip inductors. more...

M-type Hexa-ferrites powders of chemical composition Ba0.5Sr0.1Zn0.4Fe12O19 was prepared by the use of the co-precipitation technique. The heat treatment of this ferrite composition was done at various temperatures (700, 800, 900, 1000, 1100, and 1200 °C) for 6 h. The X-ray diffraction (XRD) analysis of all the prepared powder samples confirmed the emergence of a hexagonal structure. The high-intensity peaks of the samples were indexed and showed a single phase. The size of crystallite was obtained within the range of 21–42 nm. The surface morphology was carried out with a Scanning electron microscope (SEM). The grain size showed the hexagonal shape, and average grain sizes were in the range of ~ 211 nm. Spectral information was found using the Fourier transform infrared (FTIR) spectroscopy to confirm the phase of M-type hexaferrite. The dielectric parameters were measured within the high-frequency range of 5 MHz - 3 GHz. The dielectric constant was increased with an increase in temperature. The dielectric studies were found by the establishment of space charge polarization as per the two-layer model provided by Maxwell-Wagner and the study of phenomena of Koop's theory. The magnetic characteristics including coercivity (HcB) and retentivity (Br) were measured from BH/JH hysteresis loops. The enhancement of coercivity was observed from 1.23 × 10+3 Oe to 1.50 × 10+3 Oe, while the retentivity increased from 1.334 × 10+3 G to 1.598 × 10+3 G with an increase in temperature. Outstanding properties of synthesized materials suggested their use in large-frequency applications, including recording media and permanent magnets. more...

Ho-substituted Li–Ni ferrites with composition L i1.2Ni0.4HoxFe2-xO4; 0≤ x ≤ 0.15 were synthesized by a self-ignited sol-gel process. An annealing temperature of 950 °C is estimated via thermal-gravimetric (TGA) analysis. X-ray diffraction (XRD) scans have confirmed the formation of the ferrite phase with a spinel structure in all samples. Substitution of Ho ions on the B-site significantly reduced the porosity from 38 -to 23% and the crystallite size from 23.4 -to 21.7 nm. Microstructural analysis revealed a denser structure with an increase in Ho content. Dielectric results showed that both the dielectric loss and dielectric constant depict a nonlinear variation with the addition of Ho. Complex impedance behavior with a single semicircle for all samples suggests the predominant effect of the grain boundary mechanism. The substitution of Ho ions in place of Fe ions significantly decreased the electrical conductivity. The anisotropic Ho3+ ions reinforce the L-S coupling which consequently enhanced the coercive force from 145 -to 389 Oe, and thus the anisotropy constant. more...

The structural, magnetic, dielectric, and surface morphology of BiSnxFe1-xO3 (x = 0.0 to 1.0) was analyzed experimentally. The samples were synthesized by a simple chemical micro-emulsion method. The X-ray diffraction (XRD) analysis reveals structural distortion at A site and B site of BFO due to Sn doping in rhombohedral phase. The EDX data certify Sn is well incorporated in BiFeO3. The effect of Sn doping on crystal size and grain size has also been addressed. The FTIR analysis elaborates absorption at 555 cm−1 which is due to stretching and bending vibrations of O–Fe–O bonds. The magnetic properties are illustrated by vibrating sample magnetometer (VSM). The magnetic moments and exchange mechanism described theoretically by DFT analysis which support the experimental results. The dielectric behavior of studied materials has been evaluated by dielectric constant (ɛʹ), tangent loss (tanδ), real and imaginary part of impedance, and Cole–Cole plots in 1–3 GHz. The spin-orientated magnetism and dielectric response increase their potential for microwave absorber and sensor. more...

Recently, the unique double perovskites are continuously being used for solar cells and thermoelectric applications because of stable structures and high energy conversion efficiency. We addressed the optical and transport characteristics of X2GeI6 (X = K, Rb, Cs) by first-principle calculations. The tolerance factor confirms the structural stability. The computed band gaps 1.27 eV (K2GeI6), 1.24 eV (Rb2GeI6), and 1.13 eV (Cs2GeI6) plunge the maximum absorption in visible light zone. The first absorption bands 459 to 826 nm for K2GeI6, 477 to 885 nm for Rb2GeI6, and 653 to 992 nm for Cs2GeI6 are outstanding for visible light solar cells. While the second absorption bands are for other optoelectronic devices like surgical equipment. The optical characteristics are debated by frequency-dependent dielectric constants (epsilon(1), epsilon(2)), refractive index, and absorption coefficient. Thermoelectric performance is evaluated by large values of power factor and ultralow values of thermal conductivity for both n- and p-type of charge carriers. Highlights An alternative of organic-inorganic and Pb based perovskites Ideal band gaps 1.27 eV, 1.24 eV, and 1.13 eV of K2GeI6, Rb2GeI6, and Cs2GeI6 for solar cells Absorption in the visible region increases their potential for solar cells. Observation of ultralow lattice thermal conductivity. more...

Lakes are most diverse and interactive ecosystems in the world. In this study physiochemical parameters were determined of Mangla Dam Lake which is in District Mirpur Azad Jammu and Kashmir (AJK). Concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in samples of water, sediment, muscle, gills, intestine, liver, and kidneys of fish of the study area. Water samples showed average pH 7.64, Turbidity 2.59 NTU, Conductivity 461 µm/cm, TDS 205 mg/L and Salinity 0.22 mg/L. Low dissolved oxygen of 3.43 mg/L is recorded here. The analyzed data was compared with the international guidelines. In water concentration of Cd > Pb > Zn > Ni > Cr > Mn > Cu. In sediment concentration of Mn > Cr > Zn > Ni > Cu > Cd > Pb. Heavy metal concentrations decreased in muscles as Cr > Zn > Pb > Cd > Mn > Cu > Ni. In gills Zn > Cr > Pb > Mn > Cd > Cu > Ni. In intestine, Zn > Cr > Cu > Mn > Pb > Cd > Ni. In liver, Zn > Cr > Cu > Pb > Mn > Cd > Ni. In kidneys Zn > Cr > Cd > Pb > Cu > Mn > Ni. more...

Spinel ferrites are attractive for high frequency applications due to their larger direct current (dc) resistivity and low dielectric loss. In the present work, Co0.6Zn0.4HoxFe2-xO4 (x = 0.00 and 0.1) spinel ferrites were prepared by sol-gel method. The X-ray diffraction pattern showed that both samples had cubic spinel structure, while in sample (x = 0.1), the secondary phase (HoFeO3) was also observed. The dc resistivity was increased with the addition of holmium ions. As the temperature increased, the dc resistivity was decreased by proving their semiconducting nature. The dielectric properties were also measured as a function of temperature and frequency. The sample which was composed by the substitution of holmium ions contained low value of dielectric loss. The magnetic properties were also experimentally measured by applying the field up to 2000 oersted. The small area covered by hysteresis loop proved that both samples possessed soft nature of magnetic materials. more...

Spinel ferrites with composition MnLayFe2-yO4 (y = 0.00, 0.025, 0.05, 0.075, 0.10) were manufactured via the sol–gel route and characterized under different techniques to evaluate the microwave, magnetic, structural and electrical behavior. All the samples have cubic structures as perceived from XRD data. The impedance became enlarged with an increase of rare earth ions. Hysteresis loops (M vs. H) were drawn on behalf of VSM data within the fixed range of − 2 to + 2 KOe. Remanence magnetization and saturation values were decreased with the substitution of rare earth contents. Microwave properties were measured using cavity perturbation. The real and imaginary parts of permittivity and permeability values gradually decreased with increasing frequency. The perceived consequences recommended the present system can be employed in microwave absorption applications. more...

First-principle study has been conducted using the full potential linearized augmented plane wave plus local orbital method (FPLAPW + LO) within the scope of density functional theory with generalized gradient approximation (GGA) and Generalized Gradient Approximation plus Hubbard parameters U (GGA + U) as exchange correlation potentials to study the mechanical, structural, electronic and magnetic properties of two spinels type structure compounds MgX2O4 (X = Fe and Co). The structural parameters evaluated from the solution of equation of state with GGA are consistent with experiment. For the calculation of electronic as well as magnetic properties of these compounds, we have used the GGA + U formalism to treat the d state of transition metals Fe and Co more efficiently. Moreover, the crystal fields splitting for both of the compounds are also explored. The electronic band structure and density of states predicts the half metallic/metallic nature of MgFe2O4 and MgCo2O4, respectively. The spin polarized total magnetic moments of the compounds under investigation reveal the ferromagnetic behavior of these compounds. Moreover, the elastic properties of these compounds are also calculated with GGA and compared with available calculations. These compounds are founds to be elastically stable and ductile in nature. Half metallic/metallic ferromagnetic nature of MgFe2O4 and MgCo2O4, respectively, predicts the important of these spinels in spintronic devices. more...

Laser ablation in liquid was utilized to prepare a TiO2 NP suspension in in deionized distilled water using Q-switch Nd: YAG laser at various laser energies and ablation times. The samples were characterized using UV–visible absorption spectra obtained with a UV–visible spectrophotometer (UV-Vis,) Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM). While, UV-Vis spectra showed the characteristic band-to-band absorption peak of TiO2 NPs in the UV range. FTIR analysis showed the existence of O-Ti-O bond. XRD patterns indicated the presence of (101) and (112) plane crystalline phases of TiO2. TEM images showed a spherical-like structure of TiO2 NPs with various size distributions depending on the ablation period. It was also found that there is a relationship between laser ablation time and TiO2 NP size distribution, where longer ablation times led to the smaller size distribution. The antibacterial activity of TiO2 NPs was evaluated with different species of bacteria such as Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Staphylococcus aureus, using the liquid approach. The optimum activity of TiO2 NPs is found to be against E. coli at 1000 μg mL−1. Furthermore, adding, TiO2 NPs (1000 μg mL−1) in the presence of amoxicillin has a synergic effect on E. coli and S. aureus growth, as measured by the well diffusion method. However, both E. coli (11.6 ± 0.57mm) and S. aureus (13.3 ± 0.57mm) were inhibited by this process. more...

The conversion of waste heat into electrical energy by spin Seebeck effect (SSE) can be a proficient alternative of traditional thermoelectrics. For this purpose, most efficient materials are required. In this article, we report Cs2WX6 (X = Cl, Br) ferromagnetic materials for possible SSE on the basis of results of first principles calculations combined by density functional and classical Boltzmann transport theories. The synthesis possibility of both the compounds is verified from negative values of formation energy, while the cubic phase stability is evaluated through calculated values of tolerance factor. The ductile elastic nature is confirmed from Cauchy pressure and Pugh’s condition. The lattice thermal conductivity calculated through Slack’s equation is observed to decrease with rise in temperature. Electronically, both Cs2WX6 compounds are predicted as half metallic through density of states, band structure and integral values of magnetic moments (2 µB). Moreover, from spin-dependent thermoelectric properties, large values Seebeck coefficients and figure of merit are observed in spin-down states in comparison of spin-up channel. The spin-dependent thermoelectric parameters along with half metallic character make Cs2WX6 compounds suitable for spin Seebeck effect. more...

The constricted visible light harvesting and undesirable rapid recombination of photogenerated e- and h+ set enormously hinder the activity of the photocatalysts. In this work, we design and develop two-dimensional/one-dimensional (2D/1D) S-g-C3N4/Co-NiS heterojunction with intimate heterointerface contact by self-assembly technique. The fast electron transportation of 2D S-g-C3N4 nanosheets (NSs) and the well-matched energy levels of bare S-g-C3N4 and 5% Co-NiS nanorods (NRs) cooperative support the transportation and separation of photo-carriers at the heterointerface of S-g-C3N4/Co-NiS. The as-fabricated samples were evaluated EDX, SEM, UV–vis, XRD, TEM, FTIR, XPS, BET, PL and transient photocurrent. Moreover, this well-defined construction boosts sunlight harvesting and exhibits a large surface area. Benefiting from the intimate coupling and structural features, the 20% S-g-C3N4/Co-NiS heterojunction attains a noteworthy photocatalytic methylene blue (MB) degradation rate of 100%, considerably improved than that of bare NiS (34%), 5% Co-NiS (57%) and pristine S-g-C3N4 (31%). Concurrently, the photocorrosion of bare S-g-C3N4 was suppressed by simultaneous integrating with NiS and engineering with cobalt, which was demonstrated through a chemical stability test with 6 consecutive experimental tests. Such outstanding enrichment in photocatalytic activity and chemical stability was primarily attributed to boosting spatial charge separation and synergistic effects of the 20% 2D/1D S-g-C3N4/Co-NiS nanocomposites (NCs). Antibacterial performance of 20% 2D/1D S-g-C3N4/Co-NiSNCs against 4 infectious species was evaluated in visible light radiance. Our results emphasize the great importance of the efficacious heterointerface blend of 2D/1D S-g-C3N4/Co-NiS NCs as a promising photocatalyst scheme for enhanced photocatalytic degradation of dye and disinfection of pathogens. more...

Group III-V semiconductors are extensively studied for various technological applications. Different properties of Ga1-xInxP such as electronic, optical, elastic, thermal and mechanical properties were studied under different concentrations. However, there is no evident for thermoelectric performance of Ga1-xInxP (x = 0.0, 0.25, 0.50, 0.75 and 1.0). In the present study, the structural, electronic and thermoelectric behavior of Ga1-xInxP computed by utilizing the WIEN2K package. The InP show indirect semiconductor nature of band gap of 2.1 eV. By adding the concentration of In, the band gap nature shifts from indirect to direct with a decrease in the band gap. For thermoelctric properties, Seebeck, thermal and electrical conductivity, power factor and figure of merit ZT are investigated through the BoltzTraP code. Our study reveals that Ga1-xInxP has a maximum value of ZT = 0.79 at x = 1, provide an opportunity for developing good thermoelectric devices. more...

The vacancy ordered double perovskites are attractive materials for applications in optoelectronics, and other renewable energy technologies. In this research work, we have addressed the electronic, optical, thermoelectric, and thermodynamic properties of Cs2TiCl6 and Cs2TiBr6 double perovskites. The structural and dynamical stability is ensured by Goldsmith tolerance factor and positive phonon frequencies, respectively. The elastic constants, Poisson's, and Pugh's ratio show the mechanical stability and ductile behavior. Their ultralow thermal conductivity appears as important factors for device fabrication. The band structures reveal indirect band gaps 2.87eV, and 2.17eV for Cs2TiCl6 and Cs2TiBr6, respectively. The optical analysis has been done using the computed dielectric constant, absorption coefficient and refractive index. Thermoelectric calculations are executed using BoltzTraP code to investigate the electrical conductivity, thermal conductivity and Seebeck coefficient. The computed figure of merit (0.75 for Cs2TiCl6 and 0.78 for Cs2TiBr6) at room temperature reveals their excellent potential renewable energy applications. more...

Nano particles were already being used in various sectors like engineering, industry, information technology and security; and have gained attention in field of environment for pollution remediation and soil quality improvement since last decades. It was the need of hour to investigate nano materials to improve soil quality sustainably. In this scenario, present study was designed and conducted to check the capacity of carbon based nano fibers and nano tubes to stabilize degraded soils. Study investigated that carbon nano fibers and carbon nano tubes caused decrease in soil specific gravity (g/cm3) from 2.6 to 2.53 and 2.54, respectively in presence of 0.2% of selected carbon nano materials. However, increase in soil pH value from 6.9 to 7.2 was observed with this improvement. Soil dry density increased from 1.48g/cm3to 1.99g/cm3 in presence of 0.05% of carbon nano fibers and from 1.48g/cm3to 1.49g/cm3 in the presence of 0.05% of multiwalled carbon nano tubes. Both carbon nano fibers and multiwall carbon nano tubes enhanced soil plastic and liquid limits. Results concluded that carbon nano fibers and carbon nano tubes have good potential in stabilizing degraded soils. more...

International audience; Benzene-sulfonohydrazide (ECMMBSH) Schiff base has been made available in an excellent yield via reflux dehydrate of 4-methylbenzene-sulfonohydrazide with 9-ethyl-9H-carbazole-3-carbaldehyde in EtOH. The synthesis of the ECMMBSH was monitored via two main spectroscopic techniques FT-IR and UV–vis tools; ECMMBSH was characterized via MS, 1H NMR, FT-IR, CHN-EA, TG/DTG, EDX, and UV–vis., analysis. Moreover, DFT-optimized, Molecular Electrostatic Potential (MEP) and MAC/NPA-charge models were performed for ECMMBSH. The HOMO/LUMO and Density of State (DOS) calculated energy levels were compared to Tuac experimental optical energy gap values in methanol. Additionally, the TD-DFT and UV–vis. experimental absorption behavior was matched under the same condition. Moreover, the chemo-sensation effect of the ECMMBSH towered Cu2+ ions via complexation was evaluated by naked eye in addition to the UV–vis spectrophotometric measurements. more...

In this research, the sol-gel technique has been used for the preparation of titanium dioxide (TiO2), 1% cerium doped titanium dioxide (Ce–TiO2), 1% Ce–TiO2/TiO2, and TiO2/1% Ce–TiO2 films. XRD pattern verified that all the films consist of TiO2 anatase phases. The crystallite size of bilayer film is larger than that of a single deposited film. According to UV–Visible spectroscopy, the film Ce–TiO2/TiO2 has low band gap energy (Eg) value of 3.28 eV. The DSSCs of these films are fabricated with N719 dye and iodide/tri-iodide electrolyte. Various parameters including short circuit current density, open circuit voltage, fill factor, and efficiency of the cells are determined through J-V curves. The results exhibited that 1% Ce–TiO2/TiO2 film has achieved a maximum efficiency of about 3.08%. more...

Activated carbons (ACs) have been widely used for dye removal and for H2 storage but often demonstrate limited performance due to their low porosity and lacking beneficial surface functional groups. Herein, we have designed a series of urea/thiourea and K2CO3 modified ACs from “sucrose – a biomass-derived carbohydrate” via two-step pyrolysis/activation method. As-prepared ACs demonstrate excellent textural features (e.g., specific surface area (SSA) = 2842 m2/g; pore volume = 1.35 cm3/g) and optimal heteroatom content (N = 4.1 at%; S = 2.1 at% content). Moreover, these ACs exhibit an outstanding methylene blue (MB) adsorption capacity ~398.09 mg/g at an initial concentration of 200 mg/L surpassing most biomass derived ACs reported previously. The π–π stacking, hydrogen bonding and acid-base interaction is the key mechanism behind excellent MB adsorption from aqueous solution. Moreover, an efficient H2 adsorption capacity up to 2.21 wt% was observed at 77 K/1 bar with predominant role governed by narrow micropores (~0.68 nm). Therefore, the current study proposes a straightforward synthetic protocol for developing a multifunctional material (ACs) which not only act for wastewater remediation but also as energy sorbents. Moreover, our study clearly demonstrates the role of porosity and heteroatom content on both MB adsorption and H2 storage performance. more...

We present thermoelectric properties such as the Seebeck coefficient, thermal conductivity, electrical conductivity, figure of merit, and power factor of Tl2(Se, Te)Cl6 vacancy-ordered double perovskites obtained with use of the BoltzTraP code. For input files, structural and electronic properties were calculated with the full potential linearized augmented plane wave method within the Wien2k computational code. The mechanical and thermal parameters were computed for calculation of the lattice thermal conductivity. Both compounds were found to have indirect band gaps (2.976 eV for Tl2SeCl6 and 3.037 eV for Tl2TeCl6). The valence bands were observed to be flat, which results in large values of the Seebeck coefficient (S) of 183.50 μV/K for Tl2SeCl6 and 185.49 μV/K for Tl2TeCl6 at room temperature. In addition, positive values of S determined the p-type conductivity in these compounds. The power factor, figure of merit, and electrical conductivity were found to increase with temperature, while the thermal conductivity was found to decrease, hence confirming the semiconductor nature of Tl2(Se, Te)Cl6 compounds as predicted by their electronic properties. The figure of merit of these compounds was found to be higher than that of conventional metal halide perovskites. This makes the compounds investigated potential candidates for thermoelectric applications involving halide perovskites. more...

The conversions of light energy and heat energy into electrical energy are the leading source of renewable energy and extensively studied from the last decade. Therefore, we have explained structural, elastic, optical, and thermal properties A2NaInI6 (A = Cs, Rb) by density functional theory based Wien2K code. Computations of spin–orbit coupling (SOC) for speculating the precise bandgap and association of with SOC and without SOC is established. Poisson ratio and Pugh’s ratio for both compounds in this study endorsed the character of ductility. The direct gaps for (Cs/Rs)2NaInI6 are 1.111 eV/1.121 eV calculated which are essential for solar cells. The optical properties are examined for optical properties. Large absorption coefficients in the near-visible region for both compounds certify that these compounds are suitable solar cells. Thermoelectric properties and figure of merit (ZT) systematically evaluated in the temperature range of 200–800 K. more...

The structural, electronic, optical, and thermoelectric properties of MgX2O4 (X ​= ​Sb, Bi) are addressed by density functional theory (DFT). The thermodynamic stability is confirmed by means of formation energy. Band structure calculation by modified Becke and Johnson potential (TB-mBJ) reveals MgSb2O4, and MgBi2O4 possess indirect band gaps of 1.49 ​eV, and 2.35 ​eV. Optical properties are analysed by dielectric constants, absorption, refraction, refractive index etc. Further, the thermoelectric performance of these materials is explored by electrical conductivity, thermal conductivity, power factor, Seebeck coefficient, and figure of merit (ZT). The magnitude of ZT at room temperature are 0.74 and 0.72 for MgSb2O4 and MgBi2O4 led that these materials are remarkable for thermoelectric devices. more...

Herein, Sol-Gel method was employed to synthesize single phase Bismuth Iron Oxide (BFO) nanoparticles. The effect of calcinating temperature (400–700 °C) on crystallinity of nano-samples has been studied. The improvement in crystallinity is evident from growth of crystallites with an average size between 12 and 15 nm. Further, the microstructural analysis performed with Scanning Electron Microscopy (SEM) which reveals an average size of grains i.e. (17–32 nm), consistent to XRD data. In addition, the dielectric constant of prepared nanoparticles was determined which demonstrate a substantial effect of annealing temperature. The minimum value of dielectric constant was achieved at higher frequency. Moreover, the temperature and frequency dependent tangent loss, dielectric constant and bulk modulus have been studied. Based on these excellent results, we suggest that our prepared BFO nanoparticles possess potential applications in advanced magneto and ferroelectric devices. more...

Hemilabile neutral Ru(II) complexes of type trans-RuCl2(η1P∩O)2N∩N, (P∩O = Ph2PCH2CH-(OCH3)2,N∩N = 1,3-diaminopropane (1) and 1,2-diaminopropane (2) were made available in high yield. The hemilabile phenomena in P∩O ligand formed RuCl2(η2P∩O)2, the trans to cis isomerization and Halochromism reactions were monitored individually via liquid 31P{1H} NMR. The desired new complexes were identified by UV–Vis, CV, CHN-elemental analysis, fast atom bombardment mass spectrometry (FAB-MS), 1H-, 31P-{1H}, 13C{1H}-NMR and TG/DTA. Moreover, complex 1 was subjected to DFT-optimization, HOMO/LUMO, density of state (DOS), and molecular electrostatic potential (MEP) computations. The experimental thermal behavior was also determined by TG/DTA in an open atmosphere. The time-dependent density functional theory (TD-DFT) was matched successfully to the Absorption behavior of complex 1 in CH2Cl2. more...

The restricted visible light captivation and unwanted prompt recombination of photoinduced carriers remarkably hinder the activity of photocatalysts for the removal of organic pollutants. In this study, a new type heterojunction 1D/2D photocatalyst based on cobalt doped NiS nanorods (NRs) S-g-C3N4 nanosheets (NSs) was effectively fabricated by self-assembly technique, and its photocatalytic performance for methylene blue (MB) degradation and antibacterial activity under visible light were explored. The quick electron transport of S-g-C3N4 NSs and the compatible energy band positions of S-g-C3N4 and 4% Co-NiS NRs synergistic accelerate the separation and transmission of e- and h+ pairs across the Co-NiS/S-g-C3N4 heterointerface. The as-constructed heterostructures were assessed by cutting-edge analytical techniques such as SEM, XRD, EDX, FTIR, TEM, UV–vis, XPS, PL, transient photocurrent and BET. Additionally, this rational design enriches visible-light absorption and demonstrates a high BET surface area. Advantaging from the combing effect of 1D and 2D nanostructures, the 25% Co-NiS/S-g-C3N4 heterostructures achieve a significant photocatalytic MB removal rate of 98%, substantially enriched than that of undoped NiS NRs (32%), 4% Co-NiS NRs (55%) and S-g-C3N4 (29%). Simultaneously, the inherent photo-corrosion feature of S-g-C3N4 was stifled by concurrent coupling with Co-NiS NRs and modifying with Co, which was proved over a stability assessment with 6 repeated experimental results. Antibacterial activity of 25% 1D/2D Co-NiS/S-g-C3N4 nanocomposites (NCs) alongside four bacterial species was explored by irradiation of visible light. Our findings highlight the inordinate distinction of the successful heterointerface coupling of Co-NiS/S-g-C3N4 1D/2D heterojunction as a potential photocatalyst system for boosted photocatalytic removal of MB and decontamination of pathogens. more...

The perovskite stannates Sr1-xBaxSnO3 (x = 0.0, 0.25, 0.50, 0.75, 1.0) are studied theoreticaly to explore them for energy applications. The doping of Ba changes the structural behavior of studied compounds. The studied compound has direct band gap at x = 0.25 and 0.75 while indirect band gap at x = 0.0, 0.50 and 1.0. The band gap tuned from ultraviolet to visible region (4. eV to 1.7 eV) but the direct nature x = 0.25 and 0.75 increases their potential solar cell applications at specific composition. The reported optical properties show the maximum absorption of light and refractive index is favourable for solar cells. Finally, the transport properties have been elaborated by solving the Boltzmann transport equation. The doping composition Sr0.50Ba0.50SnO3 increases the figure of merit up to 0.74 which is suitable for thermoelectric applications. more...

Highly efficient Ag-doped ZnO (Ag-ZnO)/sulfurized graphitic C3N4 heterostructure photocatalyst was synthesized in a two-step hydrothermal route. Initially, Ag (1–9%) was doped into ZnO nanostructure and checked photocatalytic properties. 7% Ag-doped ZnO (7Ag-ZnO) NPs shown best photocatalytic methylene blue (MB) dye degradation under visible radiation, so, it was selected for forming composite with S-g-C3N4. In 1st step, S-g-C3N4 was synthesized by calcinating. In the 2nd step, 7Ag-ZnO/S-g-C3N4 heterostructure photocatalyst was formed by in situ formation of 7Ag-ZnO NPs in the presence of different contents of S-g-C3N4 (3.5–75 wt%) through hydrothermal route. As a result of 7Ag-ZnO/S-g-C3N4 heterostructure, a large number of catalytic active sites were generated for photocatalytic degradation. Interestingly, the 7% Ag-ZnO nanoparticles (NPs) with 25% S-g-C3N4 exhibited 97% MB degraded within 40 min, which was degraded up to 57% by 7Ag-ZnO alone. Moreover, the photo corrosion of ZnO NPs was inhibited by doping with Ag and coupling with S-g-C3N4. more...

The vacancy ordered double perovskites are emerging compounds for optoelectronics, and transport properties. In this article, optical, thermoelectric, mechanical, and thermodynamic properties of Rb2GeCl6 and Rb2GeBr6 are investigated comprehensively. The phonon band structures, and tolerance factor confirm their thermodynamic, and structural stabilities. The direct band gaps 2.60 eV and 1.78 eV are reported at Γ-symmetry point which ensure the absorption of light from visible to UV regions. The less dispersion of light, and refractive index range 1.5–2 along with broad absorption band in visible to UV regions make them outstanding materials for optoelectronics, Moreover, the transport characteristics are addressed by electrical conductivity, thermal conductivity and Seebeck coefficient, and Figure of merit. The room temperature ZT values 0.78, and 0.74 also ensure their importance for thermoelectric applications. The mechanical properties confirm their ductile, ionic, and anisotropic nature. The high Debye, and melting temperatures increases their heating resistant capacity and stability. more...