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This study presents the effect of chitosan on the properties of zinc ferrite nanoparticles suitable for potential biomedical applications. The co‐precipitation method is employed to fabricate these bio‐composites that exhibit excellent microstructural properties. The X‐ray diffractometer (XRD) analysis confirms the presence of a cubic spinel structure in the zinc ferrite‐chitosan bio‐composites, indicative of their crystalline nature. Scanning electron microscope (SEM) imaging revealed spherical particles with a size distribution below 100 nm, demonstrating the successful synthesis of homogenous nanosized particles. Fourier transform infrared spectroscopy (FTIR) spectroscopy analysis identifies the active functional groups within the bio‐composites, providing valuable insights into the molecular structure and interactions present in the synthesized materials. The presence of chitosan is confirmed, highlighting its role in modifying the chemical composition and enhancing the biocompatibility of the samples. UV–vis absorption spectra analysis reveals that the samples exhibits absorbance within the visible range. Vibrating sample magnetometer (VSM) analysis demonstrates the superparamagnetic behavior of the samples. Remarkably, these formulated samples exhibit superparamagnetism with zero coercivity and a magnetization of ≈0.0125 emu g−1 at 5 kOe when doped with chitosan. These properties are crucial for potential biomedical applications making it a promising candidate for various biomedical applications. [ABSTRACT FROM AUTHOR]

Nanoparticles of zinc selenide (ZnSe) were produced by an innovative, uncomplicated, and extremely rapid process that took no longer than a few seconds. For the production of zinc ions, zinc chloride was utilized, and selenium was used for the production of selenium ions. The effect of Zn to Se ions ratio on optical properties has been examined. The prepared nanoparticles were tested and characterized by using transmission electron microscope TEM, scanning electron microscope SEM and UV–Visible spectroscopy. The morphological results revealed that the ZnSe has a spherical shape with mean diameter around 15 nm and the band gap of the ZnSe increases with increasing the Zn content in the sample. The prepared materials were tested as antibacterial agent. [ABSTRACT FROM AUTHOR]

In this study, we present the first comprehensive investigation of the temperature-dependent band gap energy of anatase TiO2 nanoparticles, utilizing transmission measurements in the range of 10–300 K. X-ray diffraction pattern exhibited nine peaks related to tetragonal crystal structure. Scanning electron microscope image showed that the nanoparticles with the dimensions of 25–50 nm were found as micrometer sized agglomerated. When the spectrum obtained as a result of the transmission measurements was analyzed, it was seen that the band gap energy decreased from 3.29(5) to 3.26(6) eV as the temperature was increased from 10 to 300 K. Temperature-band gap dependence was analyzed using Varshni and O'Donnell-Chen optical models and optical parameters of the TiO2 nanoparticles like absolute zero band gap energy, rate of change of band gap with temperature and average phonon energy were reported. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) nanoparticles were prepared by the sol–gel method and the structural, morphological, and optical properties were investigated at different sintering temperatures of 500, 600, 700, 800, and 900°C. A tetragonal structure of anatase, mixed (anatase–rutile), and rutile phases are observed in the X-ray diffraction (XRD) analysis. Pure anatase phase formation occurred at 500°C, whereas anatase-to-rutile phase transformation began at 600°C, and reaching complete conversion to rutile at 800°C. The average crystallite size increased from 23 to 34 nm for anatase and 38 to 62 nm for the rutile when sintering temperature increased from 500 to 900°C. The scanning electron microscope (SEM) result presented the increase of grain size (25–100 nm) with increasing the sintering temperature. The Fourier transform infrared (FTIR) spectra demonstrated the presence of TiO2 vibrational bonds in all samples. The optical bandgaps of the sintered TiO2 nanoparticles decreased with rising sintering temperature. Photoluminescence spectra exhibited three characteristic peaks centered at 380, 450, and 550 nm. The emission intensity increased with increasing the sintering temperature. The Mie analysis was also studied to calculate scattering cross-section, forward scattering, and asymmetry for different grain sizes. The results showed that by increasing the nanoparticle diameters, the peaks of all spectra are redshifted for larger grain sizes and cross-section peaks shift to high values. In this study, the sintering temperature is observed to have a strong influence on crystalline phase transformation, microstructure, and optical properties of TiO2 nanoparticles. The TiO2 sample sintered at 900°C shows the best result to be used as luminescent material due to the low optical bandgap energy. [ABSTRACT FROM AUTHOR]

In this work, hydrothermal synthesis of NiO nanoparticles in aqueous solutions at higher temperatures was used. An investigation of its optical and electrical capabilities might be done in many ways. As a result, the size and structure of NiO nanoparticles were characterised using a scanning electron microscope. A powder X-ray diffractometer was used to measure experimentally the crystallite grain size and dislocation density, which were computed using the Scherer formula. The functional groups of the title nanoparticles were easily distinguishable in the FTIR spectrum. After optical absorption analyses, NiO nanoparticles were shown to have optimised UV-Visible transmittance. The density functional theory (B3LYP) was used to compute the bonding of molecular properties of NiO in the ground state using the basis sets 6-311+G (d, p) and 6-311++G (d, p). There is evidence of charge transfer in molecules based on the computed molecular electrostatic potential (MESP), Thermodynamic properties, HOMO and LUMO energies determined. The scientific applications of this NiO nanomaterial would be well served by this material. [ABSTRACT FROM AUTHOR]

In this paper, tungsten oxide thin films were synthesized successfully by the laser pulse deposition (PLD) method using a pulsed laser (ND-YAG) and wavelength (1064 nm) on a glass substrate at different laser fluencies. The effect of increasing laser fluency on the optical and structural properties of WO3 nanoparticle thin films were investigated by UV-Visible spectrophotometer, X-Ray diffraction (XRD), atomic force microscope (AFM) and Scanning Electron Microscope (SEM). X-Ray measurements for all samples of WO3 NPs thin films have shown that by increasing the laser fluencies from 5.175 to 6.369 J/cm², the intensity of the (2 01) diffraction peak increases due to the film continuing to grow with increased crystallization. [ABSTRACT FROM AUTHOR]

Sn1−xLaxO2 nanoparticles (x = 0, 0.001, 0.01 and 0.1) were prepared using a polyol method. X-ray diffraction patterns showed that only the tetragonal rutile phase is present for x = 0, 0.001, and 0.01. For Sn0.9La0.1O2, in addition to the tetragonal phase, a SnO impurity phase is present for x = 0.1. Fourier transform infrared spectroscopy (FTIR) measurements spotted the variation of local defects and grain size of the prepared nanoparticles. Scanning electron microscope (SEM) images revealed no variation in the microstructure of SnO2 with La doping except for x = 0.1. Ultraviolet–visible absorbance spectroscopy (UV–vis) was utilized to investigate the optical properties and the evolution of the band gap with lanthanum doping. A Brunauer-Emmett-Teller (BET) specific surface area (SSA) method was performed to determine the surface properties of the prepared samples. Vibrating-sample magnetometer (VSM) measurements revealed room temperature ferromagnetism in all the prepared samples. The electron spin resonance (ESR) response shows a clear dependence on La doping. Deep analysis of VSM and ESR results was performed in the frame of the bound magnetic polaron model to understand the origin of room temperature ferromagnetism in these compounds. [ABSTRACT FROM AUTHOR]

In this work, we have prepared cerium oxide (CeO2) nanoparticles (NPs) by laser ablation in water at different laser energies. The structural and optical properties of synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, energy dispersive X-ray (EDX), and UV-Vis absorption. XRD results confirmed that the synthesized cerium oxide NPs were crystalline in nature with cubic structure. SEM investigations show that the nanoparticles having a spherical shape with diameter ranged from 26 to 37 nm depending on the laser energy. The antibacterial activity and minimal inhibition concentration of synthesized CeO2 NPs against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were examined. Bacterial adhesion test of cerium oxide NPs was also determined under different incubation temperatures. Cytotoxicity of CeO2 NP effect against the human throat cancer was studied. The cytotoxicity effect of CeO2 NPs synthesized at 160 mJ on the cancer cells caused a free radical releasing which causing oxidative stress. The cytotoxicity effects of ceria NPs against human throat cancer (RD rhabdomyosarcoma cell line) and mouse fibroblast L cell (L20B cell line) growth were 33% and 13%, respectively. [ABSTRACT FROM AUTHOR]

Over the past decade, electrochemical devices have significantly improved due to advanced fabrication and synthesis of nano-electrode materials. However, the cost-effective and -efficient fabrication of nanomaterials is still challengeable. In this regard, we have used bio-organic compounds of E. cognata as fuel to synthesize and functionalize the Co3O4 nanoparticles and then incorporated NiO–PdO–Pd following the hydrothermal route. X-ray diffraction revealed Co3O4:NiO–PdO–Pd phases with crystallite size of 21 nm while spherical-shaped nanoparticles are observed by scanning electron microscope. The X-ray photoelectron spectroscopy revealed the presences of organic-functional groups of E. cognata on the surface of synthesized nanomaterial. The as-synthesized Co3O4:NiO–PdO–Pd nanomaterial is investigated as supercapacitor electrode material. In 3 M KOH the Co3O4:NiO–PdO–Pd nanomaterial exhibits a specific capacitance of 217.4 F/g. The Co3O4:NiO–PdO–Pd was reach up to 142.91 F/g at 10 mV/s while 115.15 F/g of capacitance is achieved by GCD data. Moreover, excellent conductivity is revealed by lower internal Ohmic resistance of 0.71 Ω which corresponds to the efficient transport of charges, and promotes the electrolyte diffusion. These results indicate that Co3O4:NiO–PdO–Pd nanomaterial can be a potential electrode for supercapacitor application. [ABSTRACT FROM AUTHOR]

A new molecular precursor Ca[SbO(SCH2COO)Cl H2O] was synthesized from the reaction of calcium thioacetate with SbCl3 in (1:1) ratio. The precursor was characterized by elemental analyses, infrared spectra (IR), and thermal analyses (TGA). IR spectra indicated that thioacetate chelates Sb in a binegative bidentate manner via thiol sulfur and carboxylate oxygen after deprotonation. TGA results indicated that the precursor decomposes in three steps. Calcium antimonate (CaSb2O6) was synthesized from the thermal decomposition of the molecular precursor at 250 °C in air. The calcination product was characterized by X-ray diffractions (XRD), scanning electron microscope (SEM), and transmittance electron microscope (TEM). The results of X-ray diffractions indicated the formation of calcium antimonate nanoparticles which crystallizes in hexagonal system. The crystallite size was found to be 32 nm. Electron microscopes (SEM and TEM) indicated the formation of aggregates of spherical nanoparticles that forms rod like shape. The optical band gap (Eg) measurements showed allowed direct electronic transition. The determined Eg value is 3.9 eV, which is larger than the bulk. [ABSTRACT FROM AUTHOR]

Copper sulfide -CuxS nanoparticles has been synthesized in thin films of polyvinyl alcohol polymer (PVA) matrix by successive ion layer adsorption and reaction (SILAR) method. The effect of the concentration of solution (0.1M and 0.25M) and the ambient temperature (25°C and 50°C) on formation process of nanoparticles was studied. For studing of the thermal annealing effect on nanocomposites which samples had been prepared at 25°C temperature (70 °C and 100° C) for 4 hours were annealed in the vacuum oven. The structure, morphology, elemental analysis and optical properties of the samples were investigated by X-ray diffraction (XRD), UV-Vis spectrophotometer and Scanning Electron Microscope (SEM).The band gap value has decrease as a result of the growth of particle size due to the increasing of the concentration and number of growth cycle of the sample. [ABSTRACT FROM AUTHOR]

Up-conversion (UC) phosphors with multiple functions are highly desirable for many potentially technological applications which can stimulate the miniaturization and multipurpose of modern devices. In this work, Tm3+- and Yb3+-codoped SrBi 4 Ti 4 O 15 (SBT:xTm3+/Yb3+) nanoparticles have been first synthesized by a convenient EDTA-citrate method. The structures and morphologies of SBT:xTm3+/Yb3+ were measured by powder X-ray diffraction, Fourier transform infrared reflectivity spectra and scanning electron microscope. Under 980 nm excitation, SBT:xTm3+/Yb3+ exhibited strong near-infrared (NIR) and weak visible emissions. The UC emissions were unveiled to be tightly related to the Tm3+ concentration and the optimum concentration was determined as x = 0.01. The possible UC mechanism was proposed. Importantly, based on thermo-responsive fluorescence intensity ratio approach, the optical thermometric properties were characterized in the temperature range between 313 and 573 K. The maximum sensitivity of SBT:0.01Er3+/Yb3+ UCNPs was obtained as 7.5 × 10−4 K-1. Besides, excellent repeatability and stability were also realized by the thermal-cycling measurement. Furthermore, prominent photo-thermal (PT) effect was also achieved with a temperature coefficient being 0.81 °C∙mm2/mW. Under periodic laser stimulation, the PT effect of the sample displayed regular response, indicating that the PT effect can be expediently controlled by 980 nm laser. These results indicate that SBT:xTm3+/Yb3+ UCNPs could be potential candidates for temperature sensors and PT agents. [ABSTRACT FROM AUTHOR]

Abstract In this study, synthesis of pure and Cu doped lead sulfide (PbS) nanoparticles was facilely achieved. The good crystalline nature of the nanoparticles was confirmed via X-ray diffraction (XRD) analysis. Specifically, XRD data was also used to estimate the diffraction planes, lattice constants, size of crystallites, density of dislocations, and strain produced in the lattice. The XRD pattern was indexed after identifying the diffraction planes. The crystallite size was estimated to be in the range of 18–23 nm. The absence of any additional vibrational mode in Raman spectra was observed, and this confirmed the purity of PbS even at a higher Cu doping level. However, the vibrational modes exhibited some shift towards lower wavenumbers. Low dimension nanoparticles morphology and presence of Cu were investigated via scanning electron microscope/ Energy Dispersive X-Ray (SEM/EDX) analysis. Additionally, homogeneous Cu doping in final product was observed in an EDX elemental mapping image. Optical measurements were performed by recording diffused reflectance. Both direct energy gap values were estimated in the range of 1.15–1.50 eV, and this significantly exceeded that of the bulk (i.e., 0.41 eV). Dielectric and J-V electrical measurements were performed. The dc conductivity and mobility values were observed extremely high for 2.5% Cu doped PbS NPs [which correspond to 2.48 × 10−5 S/cm and 1.3 × 104 cm2/(V s)] when compared to those of pure and other doped PbS NPs. Graphical abstract fx1 Highlights • Facile synthesis of pure and Cu doped PbS nanoparticles is attained via the chemical route. • XRD, Raman, EDX and SEM mapping confirm single phase of PbS and Cu doping. • SEM shows homogeneous low dimension NPs synthesis of pure and Cu doped PbS. • Energy gap is observed in range of 1.15–1.50 eV, which exceeds that of bulk. • High dc conductivity (2.48 × 10−5 S/cm) and mobility (1.3 × 104 cm2/V s) are observed for 2.5% Cu doped PbS NPs. [ABSTRACT FROM AUTHOR]

Potassium chloride (KCl) nanoparticles were synthesized by ball milling technique with different milling time. The effect of milling time on structural and optical properties was investigated. The structural properties of the purchased samples are characterized by Raman spectroscopy, scanning electron microscope and X-ray diffraction techniques. The Raman spectroscopy of the KCl hints at an excellent alloying behavior of those compounds and a preferred crystal structure for certain composition. The optical band is calculated by analyzing the spectral behavior of the absorption coefficient in the absorption region which revealed direct transitions. The value optical band increases (4.02–5.11 eV) with increasing milling time (0–15 h) due to quantum confinement after the ball milling process. The refractive and absorption indices were calculated for all samples. The model of Wemple–DiDomenico was used to calculate the dispersion parameters. The nonlinear susceptibility of the third order and the nonlinear refractive index were calculated by linear optical parameters using the generalized Miller rule. Mechanical milling for different milling times (0, 5, 10 and 15 h) by a planetary ball mill with zirconium oxide balls has been carried out for milling KCl. The images of as-purchased KCl have regular uniformly grains distributed like cubic particles with size of around 10 μm. By increasing the milling time to 15 h, these individual regular shapes form a smaller reasonably dense having a size less than 500 nm. [ABSTRACT FROM AUTHOR]

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Cu@Ag nanoparticles with multiple morphologies were prepared using the galvanic exchange method with surfactant-free in air. The thermal stability of as-prepared nanoparticles was evaluated by thermo-gravimetric analysis and the morphology evolution of the sample as conductive ink was investigated by using a scanning electron microscope. In the meantime, the optical properties of synthesised nanoparticles were simulated by the finite-element method. It is feasible for Cu@Ag nanoparticles to be applied as a conductive. [ABSTRACT FROM AUTHOR]

Transition metal oxide (TMO) nanoparticles such as WO 3 and MoO 3 synthesized by an anodizing method showed gasochromic and photochromic properties when in aqueous solutions. In this study, we investigated the optical properties of (WO 3) 1-x -(MoO 3) x (x = 0, 0.2, 0.33, 0.5), in particular their gasochromic and photochromic response. The morphology of the synthesized nanoparticles was obtained by scanning electron microscope (SEM) micrographs. Optical band gap of the suspensions, as well as their gas sensing response time, change in optical density during hydrogen and oxygen bubbling through the solutions, and their respective photochromic spectra are all important features of their chromogenic response. These results have been collected and are presented and discussed in detail. With the help of these findings, we are able to determine the best colloidal mixture suitable for both photo and gasochromic applications. • Bistructural (WO 3) 1-x -(MoO 3) x (x = 0, 0.2, 0.33 and 0.5) nanoparticle gasochromic suspensions were prepared using a simple anodizing method. • The dynamical sensing parameters, including the optical density, gas response, and bleaching time of the nanoparticle suspensions were investigated. • The coloration process in both photo and gasochromic effects was well explained by the bistructural nanoparticle's H 2 intercalation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn-doped CuO nanoparticles was developed by a novel coprecipitation technique. • Mn2+ions are successfully introduced into the CuO lattice. • The content of Mn plays a crucial role in the lattice parameters and optical properties. • The Mn-doped CuO sample shows maximum saturation magnetization. • Reduction of energy band gap with Mn content which plays an important role in the photovoltaic applications. Structural, optical, and magnetic properties of Mn-doped CuO nanoparticles with compositional formula Cu 1-x Mn x O (x = 0.00, 0.01, 0.02) were investigated. The monoclinic structure of CuO without a secondary phase has been confirmed by X-ray diffraction (XRD) analysis. The average crystallite size was determined by Debye-Scherer's formula and found in the range of 8 nm to 14 nm. W-H analysis resulted in decreasing microstrain with an increase of Mn doping, indicating Mn incorporation in CuO host lattice. Scanning electron microscope (SEM) images indicate that the pure and Mn-doped CuO nanoparticles have spherical-like morphology. UV–vis spectroscopy measurements revealed absorbance edge as a function of Mn doping. X-ray photoelectronic spectroscopy (XPS) study indicates that both Cu and Mn ions have 2+ valences in the samples. The magnetic hysteresis loops of the nanoparticles showed paramagnetic behavior at room temperature. [ABSTRACT FROM AUTHOR]

In the present study, this report discusses the preparation and photocatalytic properties of pure, Ag and Zn doped and Ag-Zn codoped TiO nanoparticles by sol-gel method. The powder X-ray diffraction study showed that crystallite size of doped and codoped TiO nanoparticles was decreased compared with pure TiO. The decreased particles size was confirmed by high resolution transmission electron microscope and the particle size was in the range of 7-19 nm. The influence of codopant on the morphology of Ag-Zn codoped TiO was clearly observed in the field electron scanning electron microscope. From the UV-Vis diffuse reflectance spectrum, it was observed that the doping and codoping of Ag and Zn reduce the energy gap of TiO. The reduced emission intensity of doped and codoped TiO in the photoluminescence spectrum suggests that the Ag and Zn lower the recombination of electron-hole pairs. The increase of Zn dopant level (0.2, 0.4 and 0.6 mol%) at 1 mol% of Ag in the codoped TiO further reduces the emission intensity. The 0.6 mol% of Zn at 1 mol% of Ag in the codoped TiO shows higher photocatalytic degradation ability against Reactive Yellow 145 under visible light compared with all other nanoparticles. [ABSTRACT FROM AUTHOR]

ZnSe nanoflowers have been synthesized by reaction of Se powder with Zn substrates at low temperature. The as-prepared ZnSe nanoflowers were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray energy dispersive spectroscope (EDS) and Raman spectroscopy measurements. It was found that the morphologies of the as-prepared samples highly depended on reaction time. ZnSe nanoclusters and nanoflowers formed at 573 K when the reaction time was 20 and 60 min, respectively. The as-prepared ZnSe nanoflowers were composed of radically aligned ZnSe nanorods with smooth surfaces. The results of XRD, XPS, EDS, TEM and Raman showed that the as-prepared ZnSe nanocrystals were single crystals with cubic zinc blende (ZB) structure. The formation mechanism of the as-prepared ZnSe nanoflowers was also discussed. In addition, the as-prepared ZnSe nanoflowers had excellent electron emission properties. The turn-on field of the as-prepared ZnSe nanoflowers was 3.5 V/μm and the enhancement factor was 3499. The optical properties of the as-prepared ZnSe nanoflowers were also investigated. The results demonstrated that the as-prepared ZnSe nanoflowers were potential candidates for optoelectronic devices. [ABSTRACT FROM AUTHOR]

The vanadate-sillenite Bi 25 VO 40 nanoparticles were prepared through the facile Pechini method. The average size is about 70 nm. The sample was investigated by X-ray powder diffraction (XRD) and the structural refinement. The surface properties of the nanoparticles were investigated by the measurements such as the transmission electron microscopy (TEM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopic (XPS) and Brunauer–Emmett–Teller (BET) measurements. The nanoparticles have indirect allowed electronic transition and a narrow band gap of 2.31 eV. The photocatalysis was detected by the photodegradation of methylene blue (MB) solutions under the irradiation of visible-light. Hybridization of the 6s and 6p orbitals of Bi 3 + and the resulting lone electron pair yield interesting properties. The photocatalytic activity was discussed on the base of the structural characteristics such as the strong polarizing fields, rich oxygen ion vacancies, and high structure openness degree of the lattice. Bi 25 VO 40 nanoparticles could be potential in the application as a photocatalyst under visible light. [ABSTRACT FROM AUTHOR]

Nanoparticle Lead sulfide was synthesized via simple chemical method and deposited on glass substrates at different substrate temperatures by thermal evaporation technique. The synthesized nanoparticle was analyzed and confirmed by X-ray diffraction (XRD), Scanning electron microscopy SEM with EDX and thermogravimetry. The structural, optical, morphological and electrical properties of the deposited films were studied using XRD, UV-Vis, Raman, SEM with EDX, atomicforce microscopy AFM and Hall Effect measurements. The thickness of the deposited samples was measured using thickness profilometer. The Raman shift in the peak occurs toward lower energy with increasing substrate temperature deposited lead sulfide. The Z-scan study with open aperture was carried out at 532 nm using 5 ns laser pulse on the deposited films which shows that nonlinear absorption arises from saturable absorption process. The deposited film exhibits p-type conductivity in Hall measurement. [ABSTRACT FROM AUTHOR]

In recent years, the green synthesis of nanoparticles has been the most explored area of research due to the need for eco-friendly, simple and non-toxic ways for synthesizing the nanoparticles with less waste production. In this paper, the synthesis of Ag–ZnO nanocomposite via hydrothermal method using neem leaf extracts in different solvents i.e., water and ethanol is studied. The characterization of thus prepared Ag–ZnO nanocomposites was done using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Fourier Transform Infrared spectroscopy (FTIR) and Photoluminescence (PL) to examine the structural, morphological and optical properties of the prepared nanocomposites. The I–V characteristics of the samples are also studied to determine their electrical properties. The decrease in bandgap and linear plot of I–V characterization of Ag–ZnO nanocomposite make it a suitable candidate for applications in various fields like solar cells, gas sensing, biosensors, photoanodes, photocatalysis and anti-bacterial applications etc. • The Ag–ZnO nanocomposites are synthesized using leaf extracts of Azadirachta indica (Neem) Plant in different solvents. • The present green method of synthesis is efficacious, scalable, simple and safe for environment as well as human beings. • Remarkable decrease in energy bandgap is captivated for Ag–ZnO (water) shows, coupling with Ag results in lowering the energy bandgap. • Linear I–V curve depicts enhancement in the photoactivity through Ag addition due to SPR excitation. [ABSTRACT FROM AUTHOR]

Abstract: ZnS nanoparticles with Mn2 + doping (1–2.5%) have been prepared through a simple soft chemical route, namely the chemical precipitation method. The nanostructures of the prepared undoped ZnS and Mn 2+-doped ZnS:Mn nanoparticles have been analyzed using X-ray diffraction (XRD), Scanning electron microscope (SEM), transmission electron microscope (TEM) and UV–vis spectrophotometer. The size of the particles is found to be in 2–3nm range. Room-temperature photoluminescence (PL) spectrum of the undoped sample only exhibits a blue-light emission peaked at ∼365nm under UV excitation. However, from the Mn2 + -doped samples, a yellow-orange emission from the Mn2+ 4T1–6A1 transition is observed along with the blue emission. The prepared 2.5% Mn2 + -doped sample shows efficient emission of yellow-orange light with the peak emission at ∼580nm with the blue emission suppressed. [Copyright &y& Elsevier]

The structural, morphological, optical and mechanical properties of Zinc oxide (ZnO) nanoparticles annealed at different temperatures from 500 °C to 1000 °C with a step size of 100 °C were synthesized from Sol-Gel method. The X-ray diffraction study revealed that ZnO has hexagonal Wurtzite structure. Scanning Electron Microscope(SEM) images of the studied materials possess spherical morphology with induced porosity due to change in annealing temperature. The computed size of nanoparticles from Transmission Electron Microscopy (TEM) was 21 nm. The UV–Visible Spectroscopy revealed that the band gap decreased with increase of the temperature from 3.05eV to 2.82eV. Photoluminescence (PL) spectrum of ZnO nanoparticles shows that oxygen vacancy related defects increased as the temperature increases from 500 °C to 800 °C and decreased beyond 800 °C. The wear resistance of ZnO nanoparticles is found to increase with increase of temperature owing to the generation of oxygen vacancies. The maximum friction coefficient was assigned to largest grain size. • The computed size of nanoparticles from XRD and Tem was approximately 21 nm. • The UV–Visible Spectroscopy revealed that the band gap decreased from 3.29 eV to 3.24 eV with the increase in temperature. • Photoluminescence(PL) spectrum of ZnO nanoparticles shows oxygen vacancy related defect emissions such as orange and red. • The wear resistance of ZnO nanoparticles is found to increase with increase of temperature due to the reduction in the brittle nature of ZnO which is resulted from the generation of oxygen vacancies. • The higher friction coefficient is due to the large grain size of ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

SEM images for GO-PbI 2 nanocomposite, switching behaviour and specific detectivity of the fabricated photodetector. • For the first time, the facile microwave synthesis of GO doped PbI 2 nanoparticles are reported. • X-ray diffraction and FT-Raman studies confirm the formation of GO-PbI 2. • SEM studies confirms morphology in terms of nanoparticles decorated GO nanosheets. • The optical band gap was found to be reduced by Go doping however, still higher than bulk due to confinement effect. • Photoconductivity analysis shows GO-PbI 2 has good photodetector stability and reversibility. Herein, lead iodide (PbI 2) nanorods/graphene oxide (GO) nanocomposites have been successfully achieved at low temperature via microwave-assisted syntheses route. The X-ray diffraction (XRD) analysis confirm good crystallinity and absence of any impurity in the prepared hybrid nanostructures which further confirmed through Raman analysis. The XRD and Raman study also confirm the doping of GO in 2H polytypic PbI 2 structure. The average crystallite size of PbI 2 is calculated to be 20 nm which found to be increased to 53 nm in the case of GO-PbI 2 for high intensity peak. Scanning electron microscope (SEM) images reveal that the GO sheets are decorated with PbI 2 nanoparticles and nanorods. The absorption spectra of PbI 2 was found to broaden whereas energy bandgap of GO-PbI 2 decreases to 2.83 eV in compare to 3.24 eV for PbI 2. The effect of graphene oxide doping on photodetector performance of PbI 2 was elucidated by measuring the I-V characteristics under 532 nm laser light illumination. The pure PbI 2 exhibits a stable and reversible photodetector performance with responsivity of 0.060 AW−1, detectivity of 6.38 × 1010 Jones, EQE of ∼14 % and response time of 224 ms. For GO-doped PbI 2 , these parameters were found to be improved to 0.182 AW−1, 1.79 × 1011 Jones, ∼42 %, and 128 ms, respectively. [ABSTRACT FROM AUTHOR]

• Pd2+ codoped Mn2+:ZnS nanoparticles were successfully synthesized by a simple coprecipitate technique. • Structural, Morphological and optical properties were well investigation. • Improvement in transmittance percentage and red shift of absorbance band were observed in UV–Visible analysis. • PL spectrum of Pd2+ doped Mn2+:ZnS exhibits strong red emission. Pd2+ (x = 0, 0.02 and 0.04) co-doped with Zn 0.98-x Mn 0.02 S (Mn2+:ZnS) nanoparticles were successfully synthesized by a simple co-precipitation method. The influence of the Pd2+ on the structural and morphological was investigated using the powder X-ray diffraction (XRD) pattern and Scanning Electron Microscopes (SEM) and Transmission Electron Microscopes (TEM) images. XRD pattern proved the formation of the single-phase cubic structure for the Pd2+ (x = 0, 0.02 and 0.04) co-doped Mn2+:ZnS samples. The average particle size of the Mn2+:ZnS samples were identified to be ~1.75 nm from the XRD results. Fourier transform infrared (FTIR) spectra confirm the presence of vibrational modes of the ZnS with Mn2+ and Pd2+ ions in the samples. Red shift of the absorption band was observed and the 40% enhancement in the optical transmittance behavior was estimated for the Pd2+ co-doped Mn2+:ZnS samples in the UV–Visible analysis. Photoluminescence (PL) emission spectra exhibit increased intensity in the visible region and decrease in the UV region for the Pd2+ co-doped Mn2+:ZnS samples and these improved behavior of the samples were highly preferable for the optical device applications. [ABSTRACT FROM AUTHOR]

Cobalt ferrite and nickel doped cobalt ferrite nanoparticles (NPs) was victoriously developed through chemical co-precipitation technique. The spinel crystal structure of prepared samples was confirmed by powder X-ray diffraction studies (PXRD) and also the crystalline size was calculated. Optical properties of the samples were analyzed using UV–Visible spectrophotometer and Photoluminescence (PL) studies. The bandgap was calculated using Tauc's plot and is found to be 1.83 eV, 1.92 eV, 2.12 eV, and 2.21eV for pure cobalt ferrite and (3, 7, 11) wt% Ni-doped CoFe 2 O 4 samples respectively. Further, the morphological and the compositional weight percentage (wt %) was examined using a Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectrum (EDAX) respectively. Towards application, the photocatalytic activity of the synthesized NPs was studied under direct sunlight and the maximum efficiency was obtained as 83.41%, 63.62% and 82.76% for Methylene Blue (MB), Rhodamine B (RhB) and Crystal Violet (CV) respectively. [ABSTRACT FROM AUTHOR]

Mn/Cu co-doped ZnO (Zn 0.99-x Mn x Cu 0.01 O) nanoparticles were synthesized by the solid state reaction method to investigate the relationship between the band gap and the refractive index. The stoichiometry was provided by increasing x values (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05). The X-ray diffraction (XRD) method was utilized for the structural analysis of all Mn/Cu co-doped ZnO nanoparticles. Hexagonal Wurtzite structure was established by making use of the c/a ratios of the ZnMnCuO nanoparticles. Photoluminescence (PL) properties were measured by employing the Agilent Cary Eclipse Fluorescence Spectrophotometer to discover the structural defects. The red emission with its wavelength within the range of 620–750 nm was observed. The red emission centered at 700 nm could be attributed to oxygen vacancy (V o) which was strongly dependent on the Mn concentration. The Fourier Transform Infra-Red (FT-IR) spectra (4000 - 400 cm−1) of the samples were recorded in the By PerkinElmer Spectrum Two FTIR-ATR spectrophotometer. Scanning Electron Microscope (SEM) technique was applied to determine the surface morphology, crystallite size, and the shapes of the nanoparticles. The elemental compositions of the nanoparticles were obtained by Electron Dispersive Spectroscopy (EDAX). The optical properties of the nanoparticles were obtained by using the Shimadzu 2600 Ultraviolet–Visible (UV-VIS) Spectrophotometer. The energy band gaps of the samples were calculated and the effects of dopant elements on optical properties were discussed. The refractive index was calculated by using the five different models. The maximum band gap occurred for Zn 0.97 Mn 0.02 Cu 0.01 O with a band gap energy of E g = 3.28 eV. • Mn/Cu co-doped ZnO nanoparticles were synthesized by the solid state reaction method. • XRD analysis of all Mn/Cu co-doped ZnO nanoparticles show single phase (ZnO). • The PL emissions in the green and red regions were found to be strongly depending on the Mn concentration. • Refractive index (>2) was calculated by using different models accurate within two decimal digits. [ABSTRACT FROM AUTHOR]

Co-doped CuO nanoparticles were successfully prepared by sol-gel auto combustion technique to investigate structural, optical and magnetic properties. The X-ray diffraction (XRD) analysis studied the structural properties of the nanoparticles and confirms structure of the monoclinic CuO crystal structure. As the Co doping increases the volume of unit cell decrease in Co doped CuO nanoparticles. The mean crystalline size was determined using Scherrer's formula and found in the range of 35–40 nm. The effects of Co doping on the variation of the microstrucutre property in the Co doped CuO nanoparticles were revealed by scanning electron microscope (SEM). The EDX analysis showed that the atomic percentage of Cu decreases with the increasing doping (Co) concentrations, which have confirms that the Cu atoms have successfully replaced their Co counterparts as content. The optical data revealed that with an increase in Co doping level there is an energy band gap increase. The magnetic hysteresis loops of the samples indicated that the samples are super-paramagnetic in nature. The super-paramagnetic behavior of the samples is also discussed. Average crystalline size versus strain of pure and Co doped CuO nanoparticles. Image 1 • Cu 1-x Co x O nanoparticles were synthesized by co-precipitation technique. • Single monoclinic crystal structure was confirmed. • The lattice parameters and volume decreases with increasing Co content. • The crystalline size decreased, whereas strain increased with increasing Co doping. • Cu 1-x Co x O can be used in spintronics device as the nanoparticles have super-paramagnetic behavior at room temperature. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) nanocomposite films embedded with iron (Fe) nanoparticles were prepared via the solution cast technique. The effect of Fe nanoparticles on the structural and optical properties of PVA nanocomposite films were investigated using X-ray diffraction, a scanning electron microscope, and UV–Vis spectroscopy. The size of the Fe nanoparticles was calculated using the Debye–Scherrer equation, and it was found that there was an increase in nanoparticle size after dispersion in the polymer matrix due to aggregation. Optical parameters such as optical band gap, Urbach energy, refractive index and extinction coefficient were investigated. The transmittance of a pure PVA film decreases from 82% to 18% after 3 wt% Fe nanoparticle dispersion in a polymer matrix. The direct optical band gap was found to decrease whereas Urbach energy was found to increase with the increase in Fe nanoparticle concentration. In addition, the refractive index and extinction coefficient of polymer nanocomposite films were found to increase compared to those made of pure PVA. Also, the optical dielectric and optical conductivity were observed to increase with an increase in Fe nanoparticle concentration. • The structure and linear optical properties of pure PVA and PVA filled with Fe nanoparticles were studied. • The introduction of a little amount of Fe nanoparticles tuning the refractive index of the PVA matrix. • The optical conductivity increases with increasing the concentration of Fe nanoparticles. [ABSTRACT FROM AUTHOR]