Low Temperature Solution Combustion Method Research Articles

N-regulated three-dimensional turf-like carbon nanosheet loaded with FeCoNi nanoalloys as bifunctional electrocatalysts for durable zinc-air batteries

N-regulated three-dimensional (3D) turf-like carbon material loaded with FeCoNi nanoalloys (F-CNS-CNT), composed of carbon nanotubes (CNT) grown in situ on carbon nanosheets(CNS), was synthesized using a low-temperature solution combustion method and organic compounds rich in pyridinic-N. This distinct structure significantly expands the effective electrochemical surface area, revealing an abundance of active sites and enhancing the mass transfer capability for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Both experimental observations and theoretical calculations corroborate that the synergy between the FeCoNi nanoalloy and the highly pyridinic N-doped carbon substrate optimizes the adsorption and desorption-free energy of oxygen intermediates, resulting in a remarkable improvement of intrinsic ORR/OER activity. Therefore, the derived F-CNS-CNT electrocatalyst can present a favorable half-wave potential of 0.85 V (ORR) and a lower overpotential of 260 mV (corresponding to a current density of 10 mA cm−2, OER) in alkaline media. Moreover, when employed in the air cathode of a flowable zinc-air battery, the electrocatalyst exhibits exceptional discharge and charge performance, including a high power density of 144.6 mW cm−2, a high specific capacity of 801 mAh g−1, and an impressive cycling stability of 600 cycles at a current density of 10 mA cm−2. Notably, these results markedly surpass those of the commercial catalyst Pt/C + IrO2.

Synthesis, Characterization and Investigation of Optical and Electrical Properties of Polyaniline/Nickel Ferrite Composites.

Nickel ferrite nanoparticles are prepared by using a low-temperature self-propagating solution combustion method using urea as fuel. The prepared nickel ferrite nanoparticles were doped with polyaniline in the three different weight ratios of 10%, 30% and 50% by using an in situ polymerization method and by adding ammonium persulfate as an oxidizing agent. The obtained samples were characterized by using XRD, FTIR, SEM and a UV-visible spectrophotometer. XRD examined crystalline peaks of ferrites and amorphous peak of polyaniline and confirmed the formation of the composites. FTIR examined the chemical nature of samples and showed peaks due to polyaniline and the characteristic peaks that were less than 1000 cm-1 wavenumber were due to metal-oxygen bond vibrations of ferrites. AC conductivity increased with frequency in all samples and the highest AC conductivity was seen in polyaniline/nickel ferrite 50%. DC conductivity increased in all samples with the temperature showing the semiconducting nature of the samples. Activation energy was evaluated by using Arrhenius plots and there was a decrease in activation energy with the addition of ferrite content. The UV-visible absorption peaks of polyaniline showed shifting in the composites. The optical direct and indirect band gaps were evaluated by plotting Tauc plots and the values of the optical band gap decreased with addition of ferrite in polyaniline and the Urbach energy increased in the samples with 10%, 30% and 50% polyaniline/nickel ferrite composites. The optical properties of these composites with a low band gap can find applications in devices such as solar cells.

X-ray/gamma radiation shielding properties of Aluminium-Barium[sbnd]Zinc Oxide nanoparticles synthesized via low temperature solution combustion method

For the first time Aluminium-BariumZinc oxide nanocomposite (ZABONC) was synthesized by solution combustion method where calcination was carried out at low temperatures (6000C) to study the electromagnetic (EM) (X/γ) radiation shielding properties. Further for characterization purpose standard techniques like PXRD, SEM, UV-VISIBLE, FTIR were used to find phase purity, functional groups, surface morphology, and to do structural analysis and energy band gap determination. The PXRD pattern shows (hkl) planes corresponding to spinel cubic phase of ZnAl2O4, cubic Ba(NO3)2, α and γ phase of Al2O3 which clearly confirms the formation of complex nano composite. From SEM histogram mean size of nano particles was calculated and is in the order of 17 nm. Wood and Tauc’s relation direct energy band gap calculation gives energy gap of 2.9 eV. In addition, EM (X/γ) shielding properties were measured and compared with the theoretical ones using standard procedures (NaI (Tl) detector and multi channel analyzer MCA). For energy above 356 keV the measured shielding parameters agree well with the theory, while below this value slight deviation is observed, due to the influence of atomic/crystallite size of the ZABONC. Hence synthesized ZABONC can be used as a shielding material in EM (X/γ) radiation shielding.

Low-temperature synthesis of nano-porous high entropy spinel oxides with high grain boundary density for oxygen evolution reaction

Recently, high entropy spinel oxides have become a hotspot for oxygen evolution electrocatalysts. However, high temperature preparation method offers limited control over their morphology and size, leading to unsatisfactory OER catalytic activity. It is worth noting that low temperature can prevent grain coarsening and increase the grain boundary density of catalysts, effectively promoting the OER catalytic activity. However, low temperature preparation of nano-porous high-entropy spinel oxides catalysts has rarely been reported. In this paper, a nano-porous high-entropy oxide catalyst with high grain boundary density (Fe0.2Co0.2Ni0.2Cr0.2Mn0.2)3O4 was first prepared by low temperature solution combustion method. Benefiting from the nano-porous morphology and high grain boundary density, it shows the enhanced OER activity with the overpotential of 275 mV at a current density of 10 mA cm−2, and the Tafel slope is 50.27 mVdec−1. Importantly, it also presents an outstanding long-term stability due to its high structural stability caused by high entropy, and its overpotential has almost no obvious attenuation at a current density of 10 mA cm−2 for 60 h and at a current density of 250 mA cm−2 for 40 h. This work provides a novel strategy to prepare high-performance nanostructured high entropy spinel oxides catalysts.

Ultrasensitive Electrochemical Sensor Based on SnO2 Anchored 3D Porous Reduced Graphene Oxide Nanostructure Produced via Sustainable Green Protocol for Subnanomolar Determination of Anti-Diabetic Drug, Repaglinide

Herein, we have reported on a simple, environmentally friendly, and ultra-sensitive electrode material, SnO2@p-rGO, used in a clean sustainable manner for rapid electrochemical determination of an anti-diabetic agent, repaglinide (RPG). Three-dimensional porous reduced graphene oxide nanostructure (p-rGO) was prepared via a low-temperature solution combustion method employing glycine. The aqueous extract of agricultural waste “cotton boll peel” served as stabilizing and reducing agents for the synthesis of SnO2 nanoparticles. The structural and morphological characterization was carried out by XRD, Raman, SEM, EDX, FTIR, absorption, and TGA. The oxidation process of RPG was realized under adsorption controlled with the involvement of two protons and electrons. The sensor displayed a wider linearity between the concentration of RPG and oxidation peak current in the ranges of 1.99 × 10−8–1.45 × 10−5 M and 4.99 × 10−8–1.83 × 10−5 M for square-wave voltammetric and differential pulse voltammetric methods, respectively. The lower limit of detection value of 0.85 × 10−9 M was realized with the SWV method. The proposed sensor was applied for the quantification of RPG in fortified urine samples and pharmaceutical formulations. Furthermore, the sensor demonstrated reproducibility, long-term stability, and selectivity in the presence of metformin and other interferents, which made the proposed sensor promising and superior for monitoring RPG.

Structural and Luminescence Properties of (Ba, Ca) Sio4: Dy3+ Phosphors for White Light Applications

In this report monocrystalline white-emitting phosphors Ba1.3Ca0.7SiO4 : 0.03Dy3+ were synthesized by a low temperature solution combustion method. The thermal, structural parameters and optical properties of the obtained phosphors were characterized by TGA, FTIR, XRD, SEM, EDS, TL, and PL. The mass of the Ba1.3Ca0.7SiO4 (host) sample as a function of temperature and the characteristic information about the composition kinetic analysis of thermal decomposition has provided by TGA. The characteristic spectrum of the sample was examined by FTIR. The structural parameters and appropriateness of the phase formation characterized by XRD. Photoluminescence spectra revealed strong transition at 482 nm (4 F9/2 →6 H15/2), 575 nm (4 F9/2 →6 H13/2) and weak transition at 710 nm (4 F9/2 →6 H15/2). The simulated CIE chromaticity coordinate of Ba1.3Ca0.7SiO4 :0.03Dy3+ falls in the white light region. The TL glow curve, the UV ray induced to the phosphor, and effect of dose response recorded for UV time exposure.

Strategy to probe multimodal light emissions from Eu3+/Yb3+ activated garnet nanophosphors for LED devices and solar cell applications.

This study investigates multimodal light emission from an Eu3+/Yb3+ activated Y3Ga5O12 (YGG) nanophosphor synthesized using a low temperature solution combustion method. The prepared sample possesses a cubic phase and an Ia3̄d space group and this is confirmed with X-ray diffraction and Rietveld refinement analysis. The synthesized sample shows orange-red emission bands because of the f-f transitions of Eu3+ under UV (393 nm) and NIR (980 nm) excitations via downshifting (DS) and upconversion (UC) processes, respectively. Upon UV (393 nm) excitation of the sample, the Eu3+ ions absorb this energy and then transfer it to a neighboring pair of Yb3+ ions giving NIR emission (900-1100 nm) corresponding to the 2F5/2 → 2F7/2 transition of Yb3+. The energy transfer from a single Eu3+ ion to a pair of Yb3+ ions is possible because of the quantum cutting (QC) process and this energy transfer efficiency is found to increase with the increasing concentration of the Yb3+. The quantitative estimation of energy transfer and internal quantum cutting efficiency is determined by measuring the decay kinetics. An activation energy of 0.25 eV indicates the good thermal stability of the sample. Furthermore, samples are suitable for use in practical applications in lighting devices by combining them with the near-ultraviolet (NUV; InGaN) chip. The fabricated LED device shows stability with the driving current flow values. Studies indicate that the present nanophosphor could be useful for display devices, and in enhancing the spectral conversion efficiency of the solar cells.

Synthesis, characterizations, and physical properties of magnesium oxide with polyaniline nanocomposites

Metal Oxide nanoparticles can be synthesized through physical, chemical, or green processes. Using the Green process and the low-temperature solution combustion method, magnesium oxide nanoparticles (MgO NPs) were synthesized from Aloe Vera leaves. This method is environmentally friendly and non-toxic. Magnesium oxide is a practical semiconductor metal oxide that is generally used as a catalyst, electronic, and optical material. The MgO NPs that were produced were then reinforced with polyaniline (PANI) at various weight percentages of PANI/MgO nanocomposites synthesis through in-situ polymerization. Various analytical methods were used to characterize the synthesized samples. The X-ray diffraction (XRD) pattern confirmed the formation of MgO crystalline structure with cubic phase (Halite). The Debye-Scherrer equation was used to calculate particle size, which was determined to be 35–45 nm. The study using a scanning electron microscope (SEM) revealed the development of NPs of various shapes. And also FTIR analysis was used to identify various modes of vibration, characteristic bands, and crystalline phases of the samples, and –visiblele spectroscopy was examined to study its optical property measurements of the band gap energy values 3.95 and 4.55 eV. All nanocomposites' AC conductivity, dielectric constant, dielectric loss, and tanδ fluctuation were evaluated in relation to frequency as part of the electrical studies.

Synthesis, structural, Morphological, optical, and magnetic properties of Li2−2x Ni x Al2x Fe2−2x O4, (x = 0,0.4, and 0.5) nanoparticles

Spinel lithium nickel aluminium ferrite nanoparticles (Li2–2x Ni x Al2x Fe2–2x O4), (x = 0.0, 0.4, and 0.5) were prepared through the low temperature solution combustion method. Urea is employed as a fuel for the burning process. The synthesised samples are subjected to thermal analysis, x-ray diffraction, Fourier transformation infrared, Fourier transformation Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, selected area electron diffraction, ultraviolet-visible light spectroscopy, and vibrating sample magnetometry techniques. The thermal analysis revealed a combustion reaction occurring at around 300 °C. The structural and morphology results confirmed the nanoparticle nature and required material composition. The structural, optical, and magnetic properties significantly change, all of the particle size, band gap, coercivity, remnant magnetisation, and squareness ratio revealed a decreasing trend, while the dislocation density, micro-strain, saturation magnetisation, and the magnetic moment revealed a reverse trend as increment of Al and Ni content. The obtained optical, and magnetic properties confirm that the prepared materials are optically active, and soft ferrite nanoparticles. The ease of preparation method, observed good optical and magnetic properties together with cheap and environmentally benign precursor’s sources make achieved nanoparticles as promising material for nonlinear optics, microwave devices, and memory recording and storage applications.

X-rays/gamma rays radiation shielding properties of Barium–Nickel–Iron oxide nanocomposite synthesized via low temperature solution combustion method

In the present communication, for the first time Ba–Fe–Ni oxide nanocomposite (BFNONC) was synthesized by using solution combustion method and calcined at 500oC. The synthesized sample was characterized using the techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR) and UV–Visible spectrophotometer to determine phase purity, functional group, surface morphology, structural analysis and energy band gap. The presence of diffraction peaks corresponding to BaO, Fe2O3 and NiO clearly confirms the formation of BFNONC. The average crystallite size was found to be 30 nm. The direct energy band gap determined by using Wood and Tauc's relation was found to be 2.1 eV. Further, the X-ray/gamma ray shielding properties of BFNONC in the energy range 0.081–1.332 MeV using NaI (Tl) detector and multi channel analyser (MCA) were measured. The measured shielding parameters are compared with the theory. Above 356 keV energy of X-ray/gamma ray, the measured shielding parameters agrees well with the theory, whereas slight deviation is observed below 356 keV. This deviation is mainly due to the influence of atomic/crystallite size of the BFNONC. This BFNONC finds an application as a shielding material in radiation shielding.

Magnetically active Ag–Zn nanoferrites synthesized by solution combustion route: physical chemical studies and density functional theory analysis

Nanoparticles with mixed compositions, particularly spinel ferrites with magnetic activity, have arisen as contrast agents for magnetic resonance imaging, magnetic hyperthermia. For such applications, it is desirable to possess specific particle size and physicochemical properties, i.e., magnetic response, porosity, crystallinity, and so on. It is well known that controlling specific variables in the synthetic process has a dramatic effect on final product properties and behavior. Amid preparation techniques reported in the literature, low-temperature solution combustion method has shown the ability to control and direct synthesis simply and efficiently. We are presenting a study about controlling and tuning the magnetic properties and the effect of particle size modified in Ag–Zn nanoferrites with different amounts of Co and Ni as doping metals. Different combinations of Co and Ni within Ag–Zn (Ag0.25Zn0.5-xMxFe2.25O4) nanoferrites have been synthesized using the low-temperature solution combustion technique, and this method proved to be efficient and reliable for developing homogenous, fine structured materials. X-ray diffraction confirmed that the atomic structure of prepared nanoferrites is pure and cubic, whereas electron microscopy confirmed a semispherical and monodisperse morphology with particle diameter around 20 nm. The magnetic behavior of bred materials has been explained by analyzing magnetic factors such as saturation magnetization, coercivity, and retentivity, and all experimental findings are matched with theoretical density functional theory (DFT) studies to understand the effect of each material within A and B sites in ferrite crystal cell. The observed magnetic properties highlight the superparamagnetic behavior and the effect of doping metals which is an asset in developing new materials for diagnostic and therapeutic applications. DFT modeling was achieved in an attempt to understand the effect of metal substitution in cubic ferrite cells.

Radiation shielding, photoluminescence and antimicrobial properties of Magnesium ferrite synthesized [formula omitted] low temperature solution combustion method

The present communication focuses on the synthesis, characterization of MgFe2O4 (MFO) nanoparticles (NPs) for various applications. The MFO NPs was synthesized by using solution combustion method using urea as a fuel and calcined at 500 °C. To know the phase purity, functional group, surface morphology, structural analysis and energy band gap, the synthesized sample was characterized by using the techniques such as powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR) and UV–Visible spectrophotometer. The Bragg’s reflection of PXRD confirms the formation of monophasic cubic MFO NPs with Fd−3m space group. The direct energy band gap calculated using Tauc’s relation is found to be 3.1 eV. Further, the X-ray/gamma ray shielding properties of MFO NPs in the energy range 0.081–1.332 MeV using NaI (Tl) detector and multi channel analyser (MCA) were measured. The measured shielding parameters are compared with the theory. Above 400 keV energy of X-ray/gamma ray, the measured shielding parameters agrees well with the theory, whereas slight deviation is observed below 400 keV. This deviation is mainly due to the influence of atomic size of the target medium. Hence, we can conclude that an accurate theory is necessary to explain the interaction of X-ray/gamma with the nano size atoms. The photoluminescence emission spectra consists of peaks at 447, 540 and 627 nm. The CIE and CCT coordinates clearly confirms that the present nanophosphor might find applications in display/cool white light LEDs. Furthermore, antimicrobial activity of synthesized MFO nano-particles are also studied. Viability test was conducted on two food borne pathogens such as Bacilluscereus and Pseudomonasaeruginosa. The material showed poor antimicrobial activity compared to streptomycin. Thus MFO material may unfold new prospects in the fields like shielding of X-ray/gamma ray and display applications but not a good antimicrobial agent.

X-ray / gamma ray radiation shielding properties of α-Bi2O3 synthesized by low temperature solution combustion method

In the present communication, pure and stable α-Bismuth Oxide (Bi2O3) nanoparticles (NPs) were synthesized by low temperature solution combustion method using urea as a fuel and calcined at 500oC. The synthesized sample was characterized by using powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Energy dispersive X-ray analysis (EDAX), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and UV–Visible absorption spectroscopy. The PXRD pattern confirms the formation of mono-clinic, stable and low temperature phase α-Bi2O3. The direct optical energy band gap was estimated by using Wood and Tauc's relation which was found to be 2.81 eV. The characterized sample was studied for X-ray/gamma ray shielding properties in the energy range 0.081–1.332 MeV using NaI (Tl) detector and multi channel analyzer (MCA). The measured shielding parameters agrees well with the theory, whereas, slight deviation up to 20% is observed below 356 keV. This deviation is mainly due to the influence of atomic size of the target medium. Furthermore an accurate theory is necessary to explain the interaction of X-ray/gamma ray with the NPs.The present work opens new window to use this facile, economical, efficient, low temperature method to synthesize nanomaterials for X-ray/gamma ray shielding purpose.

Structural, photocatalytic and electrochemical studies on facile combustion synthesized low-cost nano chromium (III) doped polycrystalline magnesium aluminate spinels

An economic low-temperature self-ignition solution combustion method was used to synthesize 1–11 mol% chromium ion (Cr 3+ ) doped MgAl 2 O 4 nanoparticles (NPs). The structural, morphological and energy gap variations due to the influence of Cr 3+ on the host matrix were evidenced by powder X-ray diffraction (PXRD), Fourier transformed infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), and transmission electron microscopy (TEM). Under visible light irradiation, the as-prepared NPs showed excellent photocatalytic activities (PCA) for the industrial dye Acid Red-88 (AR-88) and pyrocatechol (PY) - an emerging pollutant (EP). The experiments were carried out at room temperature in an aqueous solution at a concentration of 20 ppm. Among others, MgAl 2 O 4 :Cr 3+ (5 mol%) showed 91.38% degradation within 150 min exhibiting zero-order kinetics and 82% degradation in 6 h displaying the first order kinetics for AR-88 dye and PY EP, respectively. In this case, a greater number of hydroxyl (OH . ) radicles dominate over other reactive oxygen species (ROS), such as holes and singlet oxygens ( 1 O 2 ) under different pH conditions. Electrochemical studies have yielded the proton diffusion coefficient (D) value as large as 2.145 × 10 −4 cm 2 s −1 for the optimized NP electrode, which is substantially greater than 1.0935 × 10 −5 cm 2 s −1 for the pure MgAl 2 O 4 one owing to the intercalated anions and structurally disordered density of the electrode material. This superior electrochemical behaviour suggests the potential application of the optimized NP material as an anodic electrode for supercapacitors.

Crystal configuration, luminescence dynamics and facile combustion-fabrication of high-brightness YAG:Sm3+ nanomaterials towards competent illuminating appliances, especially WLEDs and solar-cells

New Sm3+-activated YAG nanomaterials have been fabricated via low-temperature solution-combustion method, to advance the quality of multi-phase wLEDs (white-light-emitting diodes). Cubic-phase has been configured via XRD-facilitated Rietveld technique. Fine orange-red luminescence with high color-purity and quantum-efficiency, has been attained via energization of 429 nm wavelength, such that x = 0.02 Sm3+ content has been spotted as the best possible doping-content. Obtained orange-red-coordinates (0.5868, 0.4088) are proximate to commercialized AMBER LED-NSPAR 70 BS. (NICHIA CORP.). All in all, the fabricated materials can certainly be implemented for solid-state illumination appliances, mainly warm-WLEDs, bio-imaging, security-inks, signage and solar cells.

Phytochemical mediated synthesis of praseodymium doped beta-eucryptite nanophosphor for ultraviolet stimulated fluorescence based unclonable security applications

Herein, we reported the preparation of orange-red emitting Pr3+ (1–11 mol %) doped beta-eucryptite (LiAlSiO4) nanophosphors via a simple low-temperature solution combustion method. The prepared beta-eucryptite revealed hexagonal crystal structure. The Pr3+doped beta-eucryptitedisplays broad emission peak at 608 nm along with a weak intensive peak at 632 nm ascribed to1D2→3H4and 3P0→3F2transitions, respectively. Furthermore, color coordinates of Pr3+ doped beta-eucryptite nanophosphors are well located in orange-red region. In the dispersion of ac conductivity over the frequency band comprises with two significant frequency nonresponsive and responsive conductive bands. The luminescent unclonable security ink is prepared using Pr3+doped beta-eucryptite nanophosphorsto encode security labels and are completely invisible under normal white light, while it exhibits clear orange-red emission upon ultraviolet 365 nm light. The overall aforementioned results clearly validated that the Pr3+doped beta-eucryptitenanophosphors is establish to be a suitable component for multifunctional applications.

Orange-red emitting praseodymium doped yttrium-molybdate nanophosphors for multifunctional applications

Orange-red emitting praseodymium (Pr3+) activated yttrium molybdenum oxide (Y2MoO6) nanophosphors (NPs) were synthesized via low-temperature solution combustion method using Aloe vera gel as a surfactant and fuel. The synthesized NPs were subjected to structural, morphological, optical, and electrical studies. The powder X-ray diffraction (PXRD) study reveals that the Y2MoO6 composite consists of a monoclinic crystal phase. Peak shift to the left side was observed with increase in the doping concentration of Pr3+ ions into the crystal system, which is attributed to the strain. Foamy type morphology was revealed from scanning electron microscope studies, whereas the nanostructural features of the samples were confirmed by both transmission electron microscope and PXRD. From the diffused reflectance spectroscopy study, the optical band gap was estimated to be in the range of 3.36–3.48 eV. Fourier transforms infrared spectroscopy was used to identify the metal oxygen bonds along with the other types of bonds if any. The AC conductivity and dielectric properties were measured in the frequency range of 100 Hz–5 MHz. The photoluminescence (PL) studies revealed the characteristic of emission peaks of Pr3+ ions. The Commission International de l'Eclairage (CIE) coordinates were located in orange-red color. The average correlated color temperature analysis indicates that the Y2MoO6:Pr3+ NPs can be useful for use in warm light sources. The Y2MoO6: Pr3+ (5 mol%) NPs were used for the design of anti-counterfeiting ink in security applications. The tunable properties of the prepared Y2MoO6:Pr3+ NPs make them suitable for multifunctional applications.

Solution Combustion Synthesis and Energy Transfer in LaMgAl11O19:Tb3+/Sm3+ Tunable Phosphor

Tb 3+ /Sm 3+ single as well as co-doped LaMgAl11O19 (LMA) phosphors have been synthesized by a low-temperature solution combustion method. The X-ray diffraction pattern, photoluminescence properties and energy transfer (ET) processes between rare earth (RE) ions, were investigated in detail. The mechanism of energy transfer (ET) from Tb 3+ to Sm 3+ was seen as the dipole–dipole interaction. Efficient ET from Tb 3+ to Sm 3+ ions was observed, leading to color-tunable emissions of LMA:0.02Tb 3+ , x Sm 3+ (x = 0.005 to 0.02 mol) phosphors. The efficiency of the ET gradually increased with increase in the Sm 3+ ion concentration, reaching a maximum of 78.28% at Tb 3+ ion concentration 0.02mol. The critical distance (Rc) among sensitizer and activator by the concentration quenching method was estimated to be 27.96 Å. The LMA: Tb 3+ , Sm 3+ phosphors exhibited the emission peaks in the blue ( 5 D3→ 7 FJ = 5, 4, 3, and 2), green ( 5 D4→ 7 FJ = 6, 5, and 4), and orange-red ( 4 G5/2→ 6 HJ = 5/2, 7/2, and 9/2) regions under the excitation wavelength of 375 nm. As a consequence of fine-tuning of the emission composition of the Tb 3+ and Sm 3+ ions, multicolor emitting luminescence properties can be achieved in a single host lattice LMA.

Photoluminescence properties of CaTiO3:Ho3+ nanophosphors for light emitting display applications

CaTiO3:Ho3+ (1–9 mol %) nanoparticles were prepared using low-temperature solution combustion method. All samples were characterized by powder X-ray diffraction (PXRD). Photoluminescence (PL) properties of samples were studied in detail and optimum luminescence behavior was investigated. CIE (Commission International de I'E' clairage) chromaticity chart was utilized to delineate the emission color and color co-ordinates of the sample. Correlated color temperature (CCT) was utilized to distinguish the color temperature of a light source. PL analysis, CIE and CCT diagrams indicates that the prepared nanophosphors are suitable for solid-state display applications.

Enhanced photoluminescence of SiO2 coated CaTiO3:Dy3+,Li+ nanophosphors for white light emitting diodes

Systematic analysis of SiO2@CaTiO3:Dy3+(3 mol %):Li+(0.25–1 mol %) core shell nanoparticles (C–S NPs) were carried out. CaTiO3:Dy3+(3 mol %), Li+(0.25–1 mol %) NPs were prepared using low temperature solution combustion method. C–S structured samples were synthesized using SiO2 in equal weight quantities. All samples were characterised by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) in order to study and compare its structural properties. Photoluminescence (PL) properties of uncoated and SiO2 coated samples were studied in detail and optimum luminescence behaviour was investigated. Higher luminescence intensity is observed for codoped CaTiO3:Dy3+(3 mol %):Li+(0.5 mol %) sample. Further enhancement was observed in SiO2@CaTiO3:Dy3+:Li+ structured nanoparticles. Emission spectra of SiO2@CaTiO3:Dy3+(3 mol %):Li +(0.25–1.0 mol %) C–S nanophosphors exhibit white emission dominated by 4F9/2 → 6H13/2 (570 nm) transition of Dy3+ ions under. All the results suggested that the present material provides a platform for fabricating new functional materials which can be applied in the field of wLEDs and solid state display applications.