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The present work describes comparative study of annealing temperature in the range of 500–900 °C on the successful synthesis of Gd/Mn2SnO4 nanocomposite via sol gel method followed by hydrothermal method. Structural, optical, photoluminescence, photocatalytic activities against methylene blue and methyl orange; and antifungal features against Aspergillus niger of Gd/Mn2SnO4 nanocomposite were studied. The structural and optical properties were investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), UV–Visible spectroscopy and particle size analyzer (PSA) techniques. Crystallite size, particle size and optical band gap were calculated using XRD, PSA and Uv–visible spectroscopy, respectively. Gd/Mn2SnO4 nanocomposite annealed at 500 °C is found to be a competent photo catalyst for degradation of dyes used for the study and for the growth inhibition of Aspergillus niger.

Novel approach for the synthesis of Fe2O3-CuO-MoO3 nanocomposite was established using sol-gel and ultra-sonication setup. The conformation of the synthesized nanocomposite was done using Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) techniques. The chemistry of product thermal stability and decomposition was studied using thermo gravimetric analysis-differential scanning calorimetery (TGA-DSC) with respect to increase in temperature. The optical properties were studied using UV-visible spectroscopy via Wood and Tauc relation. XRD data indicates the presence of orthorhombic crystal system with crystallite size of 4.45 and 38.71 nm using Scherrer equation and Williamson-Hall equations, respectively. The particle size was calculated using transmission electron microscopy (TEM) and found to be 12.67 nm. The catalytic ability of synthesized nanocomposite was studied against methylene blue, and the decrease in percentage degradation from 5 to 30% was observed in nanocomposite prepared from sol-gel to ultra-sonication method.

Gadolinium doped tin oxide–iron oxide nanoparticles (Gd/Fe1.727Sn0.205O3) were synthesized via sol–gel method followed by hydrothermal method. Ethylene glycol played the role of directing agent to control surface morphology. Physical and optical properties of Gd/Fe1.727Sn0.205O3 nanoparticles were studied as a function of calcination temperature. Characterization techniques like thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), particle size analyzer (PSA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Visible spectroscopy (UV–VIS), and four-point probe technique have been used to study the thermal degradation, kinetics, thermodynamic properties, structural analysis, surface morphology, optical and electrical properties of nanoparticles. Prominent peaks in FTIR spectra at 563, 418, and 542 cm−1 were observed for Fe–O, Sn–O, and Gd–O, respectively. The uncalcined nanoparticles follow first order kinetics and Freeman–Carrol method was applied for calculating the activation energy. It was observed that nanoparticles calcined at 700 °C have 8.9 nm particle size calculated with particle size analyzer, which is smallest among all and having band gap energy of 2.3 eV. SEM micrographs show hexagonal geometry. The dependence of electrical resistance on temperature shows that these nanoparticles possess semiconducting behavior. These nanoparticles can be used as cathode material for solid oxides fuel cells (SOFCs) application. The nanoparticles calcined at 700 °C showed highest power density of 83.27 W cm−2 at 650 °C with open current voltage of 0.793 V.

Perpendicular magnetic anisotropy (PMA) plays a critical role in spintronics, giving rise to improvements in fundamental research and industrial production. Generally, PMA originates mainly from the spin–orbit interaction with perpendicular orbital moment. However, electron orbitals are difficult to tune once they emerge. Here, we propose a simple and effective method for preparing (001)-oriented ultrathin La0.67Sr0.33MnO3 (LSMO) films with PMA, which is induced by compressive strain and surface symmetry breaking. Moreover, PMA was effectively strengthened by means of annealing under applied magnetic field. X-ray linear dichroism spectra reveal that PMA should be attributed to the preferential occupancy of the 3z2 − r2 orbital in LSMO films. The results presented here show that PMA can be manipulated by orbital reconstruction in perovskite manganite films under compressive strain through a simple and effective strategy. These findings illustrate a new method for designing and controlling magnetic anisotropy and might advance fundamental applications of orbital physics and spintronics.

Heterogeneous semiconductor photocatalyst (Ti0.85Sn0.15O2) was synthesized by addition of TiO2 solution into Sn(OH)4 solution via sol–gel method using docusate sodium salt surfactant as model controlling agent while annealing at 800 °C. The structural, morphological and crystalline features of the synthesized sample were explored by using different microscopic and spectrophotometric techniques. The quantitative phase analysis and Rietveld refinement of XRD spectra was done to confirm the formation of Ti0.85 Sn0.15O2 nanocomposite. Optical electronegativity and refractive index was determined by using band gap energy. Their photocatalytic activity was estimated by using chlorpyrifos (CP) a class of organophosphorus pesticides, as a model of organic pollutants under solar light irradiations.

Silica xerogel was extracted from the Rice Husk Ash (RHA) through alkaline extraction method. SnO2-SiO2 and Fe doped SnO2-SiO2 nanocomposites were synthesized via sol-gel and hydrothermal methods respectively using zwitterionic surfactant i.e., N-dodecyl-N,N-dimethyl-3-ammonio-1-propane sulfate (SB3-12). Coats-Redfern method was used to determine the activation energy, enthalpy, entropy, Gibb’s free energy and pre-exponential factor for thermal degradation of nanocomposite using TGA data. The optical properties of nanocomposites were studied and band-gap was measured using Wood and Tauc expression. The red shift was observed in Fe doped SnO2-SiO2 nanocomposite having band gap of 5.2 eV. It was found that smaller bandgap of Fe doped SnO2-SiO2 photocatalyst resulted a prominent increase in photocatalytic activity of nanocomposite against Methylene Blue (MB) under illumination of sunlight.

Surfactant controlled synthesis of La/SnO2–TiO2 nanocomposite was studied by using anionic surfactant dioctyl sulfosuccinate sodium salt (DOSS) synthesized via sol–gel method followed by hydrothermal method by using different lanthanum precursors. The structural investigation, thermal degradation, kinetics, thermodynamics properties, crystallite size, morphology, surface and photocatalytic properties of synthesized samples were studied by using different characterization techniques i.e. Thermogravimetric analysis (TGA), Fourier transform-infrared spectroscopy (FTIR), Particle Size Analyzer (PSA), Powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Ultraviolet–Visible spectrophotometer (UV–VIS). Band gap calculations and optical properties of both SnO2–TiO2 and La/SnO2–TiO2 were studied by using UV–Visible spectroscopy. The performance of both SnO2–TiO2 and La/SnO2–TiO2 nanocomposites as a photocatalytic agent was also investigated for the degradation of methylene blue (MB) under the illumination of sunlight.

Endosulfan is the organochlorine pesticide and highly toxic to human and animal. Although its solubility is less in water but is persistent in soil. In this study, CeO2–ZnO nanocomposites have been prepared with hydrothermal method by using N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SB3-12) zwitterionic surfactant. Cadmium sulphide was doped on CeO2–ZnO nanocomposites to enhance its catalytic efficiency. The structural characterization was carried out by using different techniques like FTIR, XRD, DLS, SEM and UV–Vis spectroscopy. Lattice contraction and decrease in oxygen vacancies was observed with increase in dopant concentration, which can be attributed to the Cd2+ substitution on CeO2–ZnO nanocomposites. These alterations in nanocomposites ensues the increase in particle size along with the blue shift in band gap energy. The catalytic efficiency of nanocomposites against endosulfan increases when the oxygen vacancy concentration is higher (with decrease in dopant concentration).

In the present work, tin oxide–titanium oxide (SnO2TiO2) nanoparticles were synthesized via sol–gel method and doping of lanthanum (La) on tin oxide–titanium oxide (La/SnO2TiO2) nanoparticles was carried out using hydrothermal and reflux methods. Effect of different preparation methods on the size and catalytic properties of nanoparticles was investigated. The La/SnO2TiO2 nanoparticles were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, powder X-ray diffraction and solid phase spectroscopy. The UV–Vis spectroscopy was used to investigate its catalytic properties for methylene blue degradation. It was found that La/SnO2–TiO2 nanoparticles prepared by hydrothermal method have small size and maximum degradation capacity. The red shift in La nanoparticles was observed with band gap of 4.25 eV as compared to bulk material.

The influence of calcination temperature on the photocatalytic activity of quaternary metal oxide nanocomposite i.e. gadolinium (Gd) doped cobalt tin oxide (CoSnO3) have been explored. The synthesis of nanocomposite material was completed in two steps using a novel method. The synthesized nanocomposite material was subjected to various characterization techniques like thermogravimetric analysis (TGA), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), particle size analyzer (PSA), UV–Visible and photoluminescence spectroscopy in order to investigate its thermal, structural, and optical properties. The crystallite size, particle size and optical band gap estimated via XRD, PSA and UV–Visible spectroscopy, respectively reveals an increasing trend with calcination temperature. The Gd doped CoSnO3 nanocomposite material is found to be very efficient visible light photocatalyst. The photo-degradation efficiency in the presence of sunlight in degrading methylene blue and methyl orange is more than 90%. An insight mechanism of electron/hole trapping using electronic configuration has also been explored.

Gd/SnO2–TiO2 nanoparticles were synthesized by using ultrasonic and hydrothermal methods. Effect of concentration of gadolinium (Gd) precursor on particle size and activity of nanoparticles was studied. It was observed that the particle size increases with the increase in concentration of gadolinium precursor. Gd/SnO2–TiO2 nanoparticles were characterized by TEM, SEM, EDX, TGA, FTIR and powder XRD. Band gap calculation was done by using Solid Phase Spectrophotometer to determine the optical properties of nanoparticles. The effect of concentration of Gd on band gap was investigated and red shift was observed for Gd/SnO2–TiO2 from 5.3 to 2.0 eV. Photocatalytic degradation of Methylene Blue was carried out to determine the catalytic properties of Gd/SnO2–TiO2. It was found that Gd/SnO2–TiO2 nanoparticles prepared with 0.004 M concentration of Gd precursor degraded the dye more effectively as compared to the samples prepared with 0.005 and 0.006 M concentrations of Gd.

Zinc sulfide (ZnS) thin films were prepared on indium tin oxide-coated glass by electrodeposition using aqueous zinc sulfate, thiourea, and ammonia solutions at 80°C. The effects of sulfurization at temperatures of 350°C, 400°C, 450°C, and 500°C on the morphological, structural, optical, and electrical properties of the ZnS thin films were investigated. X-ray diffraction analysis showed that the ZnS thin films exhibited cubic zincblende structure with preferred (111) orientation. The film crystallization improved with increasing annealing temperature. Field-emission scanning electron microscopy images showed that the film morphology became more compact and uniform with increasing annealing temperature. The percentage of sulfur in the ZnS thin films increased after sulfurization until a stoichiometric S/Zn ratio was achieved at 500°C. The annealed films showed good adhesion to the glass substrates, with moderate transmittance (85%) in the visible region. Based on absorption measurements, the direct bandgap increased from 3.71 eV to 3.79 eV with annealing temperature, which is attributed to the change of the buffer material composition and suitable crystal surface properties for effective p–n junction formation. The ZnS thin films were used as a buffer layer in thin-film solar cells with the structure of soda-lime glass/Mo/Cu2ZnSnS4/ZnS/ZnO/Al grid. The best solar cell efficiency was 1.86%.

In this work, samarium (Sm) supported on tin oxide–titanium oxide (SnO2/TiO2) nanoparticles (Sm/SnO2–TiO2) were synthesized by sol–gel, ultrasonic and hydrothermal methods; and the optical and catalytic properties of Sm/SnO2–TiO2 nanoparticles was observed. Effect of synthetic methods on nanoparticles size and percentage composition of anatase and rutile phase in TiO2 was evaluated. The Sm/SnO2–TiO2 nanoparticles were characterized by Transmission Electron Microscopy, Scanning Electron Microscopy, Energy Dispersive X-ray spectroscopy, Powder X-ray Diffraction, Thermogravimetric Analysis and Fourier Transmission Infrared Spectroscopy. However, UV–Vis and solid phase spectroscopy were used to determine the catalytic efficiency and optical band gap, respectively. It was found out that nanoparticles synthesized by sol–gel and hydrothermal method have small optical band gap as compare to nanoparticles synthesized by ultrasonic method and ultimately showed more catalytic activity toward degradation of dye due to red shift in the optical band gap (shifting of wavelength to visible region). A direct relationship between particle size and optical band gap was investigated. It was observed that Sm reduced the optical band gap and increased catalytic efficiency when supported on SnO2/TiO2.

Gadolinium oxide–samarium oxide (Gd2O3/Sm2O3) nanocomposite was synthesized via sonication and hydrothermal methods. The sample was characterized by using thermogravimetric analysis and Fourier transformation infrared spectroscopy. The average crystalline size was calculated by Scherrer equation, Wood–Tauc relation using X-ray diffraction and transmission electron microscope. The size was found to be in a range of 15–30 nm. The morphological study was carried out with scanning electron microscope. Optical properties were investigated by solid phase and UV–visible absorption spectrophotometer. The band gap energy of the Gadolinium oxide was shifted from 5.3 eV to 2.3 eV. The change in band gap indicates red shift in nanocomposite.

We fabricated Cu 2 ZnSnS 4 (CZTS) thin films by electrochemically depositing precursor stacks on Mo-coated glass in a variety of orders: Cu/Sn/Cu/Zn, Cu/Zn/Cu/Sn, Zn/Cu/Sn/Cu, and Sn/Cu/Zn/Cu. Using Raman spectroscopy and X-ray diffraction, we found that for all stacking orders the annealed film was composed of a single CZTS phase with good crystallinity and strong (1 1 2) orientation. For the Cu/Sn/Cu/Zn stack, field-emission scanning electron microscopy revealed a homogeneous, compact surface morphology and large columnar grains. This stack also had an optical absorption coefficient of >10 4 cm −1 and an optical band gap of 1.51 eV. We fabricated a solar cell with the structure SLG substrate/Mo/Cu 2 ZnSnS 4 /CdS/i-ZnO Al:ZnO/Al, which achieved a conversion efficiency of 2.3%.

We prepared Cu2ZnSnS4 (CZTS) films on Mo-coated glass substrates by using electrodeposition in an acidic electrolyte containing Cu, Zn, and Sn species. We examined how the substrate temperature influenced the compositional, structural, morphological, and electrical properties of the CZTS films by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), Raman spectroscopy, energy dispersive spectroscopy, and ultraviolet–visible absorption spectroscopy. The film sulfurized at a substrate temperature of 580 °C exhibited the best characteristics because of its large grain size and low number of voids. At a sufficiently high temperature, this fabrication process yielded single-phase CZTS with no secondary phases. The grain size increased with deposition temperature: the size at 580 °C was about twice that at 460 °C. All the CZTS films were Cu-rich and S-poor, with the composition changing at 580 °C. XRD revealed that the films had nanocrystalline kesterite structures, indicated by intense, sharp (112), (200), (220), and (312) diffraction peaks. The crystallite size was 34.6–57.3 nm, increasing with substrate temperature. FESEM indicated that the morphology improved with substrate temperature. The optical band gaps of the films were 1.36–1.49 eV, and their absorption coefficients were on the order of 10−4 cm−1, making them quite suitable for use in solar cells. We fabricated solar cells with a structure of soda-lime glass/Mo/Cu2ZnSnS4/CdS/i-ZnO/ZnO:Al/Al and achieved a maximum conversion efficiency of ~2.69 %.

Copper zinc tin sulfide (CZTS, Cu2ZnSnS4) is a low band gap semiconductor that is attractive for use in solar cells. We investigated the dependence of the structure and properties of CZTS thin films on the temperature used to sulfurize precursor thin films composed of copper, zinc and tin fabricated by electrochemical deposition. The precursor films were sulfurized in a furnace with three zones, which allowed fine control of the sulfurization temperature between 250 and 400 °C. X-ray diffraction and Raman spectroscopic measurements confirmed that the films were composed of CZTS following sulfurization. The grain size and crystallinity of the films increased with sulfurization temperature. The composition of CZTS also varied with sulfurization temperature. The proportions of Cu and Zn increased while that of Sn decreased with increasing sulfurization temperature. Absorption and reflectance spectra revealed that the absorption coefficients and band gaps of the CZTS films varied with sulfurization temperature between 3–4.1 × 104 cm−1 and 1.4–1.53 eV, respectively. Solar cells containing CZTS sulfurized at 400 °C showed a maximum efficiency of 2.04 %, which was attributed to the higher crystallinity and larger grain size of CTZS compared with thin films sulfurized at lower temperatures. Our results show that control of sulfurization temperature is an important factor in optimizing the performance of CZTS thin films in solar cells.

In this study, gallium nitride (GaN) films were grown on n-Si (1 1 1) substrate by thermal vapor deposition method in quartz tube furnace for different growth duration. Gallium metal mixed with GaN powder and aqueous ammonia (NH 3 ) solutions were used as sources of Ga and N. Structural, elemental, and optical characterizations were carried out using various techniques in order to investigate the properties of the films. Scanning electron microscopy images showed that the films surface have self-textured morphology, which was introduced during the growth process. Moreover, further deposition resulted in the formation of heterogeneous film. X-ray diffraction (XRD) measurements reveal in all samples a typical diffraction pattern of hexagonal GaN wurtzite structure. Raman spectra demonstrated redshifts in E 2 -high with increasing deposition time due to tensile stress inside the GaN films, confirmed by XRD. The photoluminescence spectra of the films demonstrated strong near band edge emission at about 363 nm. The fabricated GaN films based metal–semiconductor-metal (MSM) UV photodetector shows a contrast ratio of ∼240–40 at +5 V and responsivity in the range of 0.28–0.01 A/W for the UV photodetectors. This study shows the possibility of synthesizing GaN films on Si wafers at low-cost and has potential applications in UV photodetection.

Solvent controlled synthesis of tin oxide nanocatalysts were prepared via the hydrothermal method. To study the effect of solvent on the particle size of tin oxide and their catalytic efficiency on photodegradation of environmental hazardous materials, the synthesis was carried out at different concentrations of solvent (isoamyl alcohol) keeping all other reaction conditions constant. The nanoparticles were characterized by FourierTransmission Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray Diffraction and Thermogravimetric analysis. Prepared nanoparticles were applied as nanocatalyst under UV-visible light for the photodegradation of methyl green,which is an abundant organic pollutant of industrial waste water. Photodegradation activities of the nanocatalysts were measured in three different ways, i. pseudo first order rate constant, “k”. ii. percentage degradationand iii. degradation rate. Effect of solvent was quantitatively explained in term of double sphere model of ion-ion interaction. Degradation of pollutants was also monitored by High Performance Liquid Chromatography.

Stress and lattice constants are significant factors considered in evaluating the deformation mode of crystalline materials. Zinc oxide (ZnO) nanostructured thin films were prepared via the process of wet oxidation of Zn at temperatures varying from 420 to 570 °C. Structural, elemental and optical characterizations were carried out using various techniques, to investigate the properties of the samples. Scanning electron microscopy (SEM) images showed improvement in the ZnO structure and the grain size of the ZnO became larger as the oxidation temperature was increased, while maintaining a constant flow rate of wet oxygen. X-ray diffraction (XRD) patterns also showed that ZnO films suffered from compressive stress due to elongation in the lattice constant. With increase in the oxidation temperature, the compressive stress became tensile stress because of the decrease in the lattice constants. Photoluminescence (PL) spectra revealed the influence of stress on the energy band gap, with wet oxidation further giving rise to the transition of stress from compressive to tensile.

In this work, cuboid kesterite Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via a rotary evaporation method, using thiorea as a sulfur source. The effects of varying the rotation rate on the properties of the cuboid Cu2ZnSnS4 nanocrystals were investigated. The samples were characterized using X-ray diffraction, Raman spectroscopy, transmission electron microscopy (TEM), and UV–vis spectroscopy. The X-ray diffraction (XRD) patterns indicated that the as-deposited CZTS nanocrystals were transformed from an amorphous state into a crystalline state with a kesterite structure at a rotation rate of 100 rpm. Results from the Raman spectroscopy experiments agreed with the XRD results. TEM and high-resolution transmission electron microscopy (HRTEM) images showed that the as-prepared samples were polycrystalline, and had a uniform nanocrystal morphology. UV–vis absorption spectra revealed strong absorption in the visible light region, with a direct band gap of 1.48 eV and an absorption coefficient on the order of 104 cm−1, which is suitable for photovoltaic applications.

In the title compound, C16H14ClN3O2S, the dihedral angle between the benzene and pyrazole rings is 52.75 (2)°, while that between the pyrazole and 4-chlorophenyl rings is 54.0 (3)°. The terminal sulfonamide group adopts an approximately tetrahedral geometry about the S atom with a C—S—N angle of 108.33 (10)°. In the crystal, pairs of N—H...N hydrogen bonds lead to the formation of inversion dimers. These dimers are linkedviaa second pair of N—H...N hydrogen bonds and C—H...O interactions, forming a two-dimensional network lying parallel to thebcplane. The two-dimensional networks are linkedviaC—H...Cl interactions, forming a three-dimensional structure.

In the title compound, C11H16N2O3S, the S atom has a distorted tetrahedral geometry [maximum deviation: O-S-O = 119.48 (15)degrees]. The dihedral angles between the benzene ring and its propylsulfonamide and methylamide substituents are 71.8 (2) and 5.8 (1)degrees, respectively. In the crystal, molecules are linked by N-m-H center dot center dot center dot O-s (m = methylamide and s = sulfonamide) hydrogen bonds, forming C(8) chains along the a axis. The two molecule chains are connected by N-H center dot center dot center dot O hydrogen bonds, generating R-3(2) (18) rings. The crystal packing is further stabilized by weak intermolecular C-H center dot center dot center dot O hydrogen bonds.

The title compound, C15H17NO2S, is twisted at the S—N bond with a C—S—N—C torsion angle of 73.90 (14)°. The dihedral angle between the aromatic rings is 36.76 (11)°.

In the title molecule, C21H21NO2S, the phenyl ring makes the dihedral angles of 74.13 (11) and 80.16 (11)° with the two benzene rings, which are inclined at an angle of 43.73 (10)° with respect to each other. In the crystal, molecules are linked by intermolecular C—H...O hydrogen bonds along the [010] direction. In addition, a weak C—H...π (arene) interaction is observed.

In the title compound, C20H18ClN5S, the toluene and triazole rings are oriented almost perpendicular to each other, making a dihedral angle of 89.97 (9)°, whereas the dihedral angle between cholorophenyl and pyrazole rings is 54.57 (11)°. In the crystal, pairs of N—H...N hydrogen bonds link the molecules into inversion dimers. Weaker C—H...S and C—H...Cl interactions are also present.

In the title compound, C15H16N2O3S, the central C—S(=O)2N(H)—C unit is twisted, with a C—S—N—C torsion angle of −56.4 (2)°. The benzene rings form a dihedral angle of 49.65 (15)° with each other. In the crystal, molecules are linked by N—H...O hydrogen bonds, generating a three-dimensional network.

The title compound, C16H19NO2S, crystallizes with two crystallographically independent molecules in the asymmetric unit in which the dihedral angles between the planes defined by the aromatic rings are 35.3 (2) and 42.5 (2)°. In the crystal, intermolecular C—H...O hydrogen bonds stabilize the packing.