X-ray Diffractometer Patterns Research Articles

Influence of intermetallic phase (TiFe) on the microstructural evolution and mechanical properties of as-cast and quenched Ti–Mo–Fe alloys

This study presents the phase analysis, microstructural characteristics, and mechanical property evaluation of the as-cast and quenched Ti–15Mo–xFe alloys with high iron content ranging from 4 to 12 weight percent. All the four alloys were produced in a vacuum-arc melting furnace. Heat treatment in the form of solution treatment was performed in a muffle furnace at a temperature of 1100 °C, with 1-h holding time and the samples were rapidly quenched in ice-brine. X-ray diffractometer (XRD) was used to analyses the phases present in each alloy whereas the optical microscope (OM) was employed to track the microstructural evolution and percentage porosity. The mechanical properties of the alloys were evaluated using a tensile test and compression test method while the micro-Vickers hardness measurements were conducted to evaluate hardness of the alloys. The XRD patterns of as-cast showed peaks belonging to the β and α″ phases and intermetallic B2 TiFe phases. The as quenched XRD peaks illustrated β phase only and Fe·Ti·O2 phases. The as-cast OM micrographs revealed equiaxed β grains, substructures, dendritic structure, and pores forming around the grain boundaries. The quenched OM showed only β equiaxed grains with pores throughout the grain boundaries. The tensile properties such as ultimate tensile strength (UTS) and elastic modulus (E) of as-cast TMF0 were 264 MPa and 79 GPa respectively and these properties changed upon quenching to 411 MPa and 66 GPa respectively. The elastic modulus of TMF1 in as-cast condition was 74 GPa. The UTS and E of TMF1, TMF2, and TMF3 in as-cast and quenched conditions were not recorded due to the fragility of the samples that failed prior to yielding any useful data. The compressive strength in as-cast and in quenched condition decreased with an increase in Fe content. The micro-Vickers hardness in as-cast and quenched conditions showed a similar trend with hardness increasing slightly upon quenching for TMF0, TMF1, and TMF3 alloys but slightly decreased in the case of TMF2. The fracture surfaces of all the as-cast and quenched alloys were comprised of ductile and brittle fracture.

Suppressing the oxygen-ionic conductivity and promoting the phase stability of the high-entropy rare earth niobates via Ta substitution

Improving and optimizing the target properties of ceramics via the high entropy strategy has attracted significant attention. Rare earth niobate is a potential thermal barrier coating (TBCs) material, but its poor high-temperature phase stability limits its further application. In this work, four sets of TBCs high-entropy ceramics, (Sm1/5Dy1/5Ho1/5Er1/5Yb1/5)(Nb1/2Ta1/2)O4 (5NbTa), (Sm1/6Dy1/6Ho1/6Er1/6Yb1/6Lu1/6)(Nb1/2Ta1/2)O4 (6NbTa), (Sm1/7Gd1/7Dy1/7Ho1/7Er1/7Yb1/7Lu1/7)(Nb1/2Ta1/2)O4 (7NbTa), (Sm1/8Gd1/8Dy1/8Ho1/8Er1/8Tm1/8Yb1/8Lu1/8) (Nb1/2Ta1/2)O4 (8NbTa) are synthesized using a solid-state reaction method at 1650°C for 6 h. Firstly, the X-ray diffractometer (XRD) patterns display that the samples are all single-phase solid solution structures (space group C2/c). Differential scanning calorimetry (DSC) and the high-temperature XRD of 8NbTa cross-check that the addition of Ta element in 8HERN increases the phase transition temperature above 1400°C, which can be attributed to that the Ta/Nb co-doping at B site introduces the fluctuation of the bond strength of Ta-O and Nb-O. Secondly, compared to high-entropy rare-earth niobates, the introduction of Ta atoms at B site substantially reduce thermal conductivity (reduced by 44%, 800°C) with the seven components high entropy ceramic as an example. The low thermal conductivity means strong phonon scattering, which may originate from the softening acoustic mode and flattened phonon dispersion in 5–8 principal element high entropy rare earth niobium tantalates (5–8NbTa) revealed by the first-principles calculations. Thirdly, the Ta/Nb co-doping in 5–8NbTa systems can further optimize the insulation performance of oxygen ions. The oxygen-ion conductivity of 8NbTa (3.31 × 10−6 S cm−1, 900°C) is about 5 times lower than that of 8HERN (15.8 × 10−6 S cm−1, 900°C) because of the sluggish diffusion effect, providing better oxygen barrier capacity in 5–8NbTa systems to inhibit the overgrowth of the thermal growth oxide (TGO) of TBCs. In addition, influenced by lattice distortion and solid solution strengthening, the samples possess higher hardness (7.51–8.15 GPa) and TECs (9.78 × 10−6 K−1–10.78 × 10−6 K−1, 1500°C) than the single rare-earth niobates and tantalates. Based on their excellent overall properties, it is considered that 5–8NbTa can be used as auspicious TBCs.

Effect of rare earth doping on the electromagnetic response of hard ferrites SrFe12O19 for potential application in high-frequency devices

This work explores the synthesis, characterization, and potential application of rare earth doping on hard ferrites, focusing on their unique electromagnetic properties for potential applications in radio frequency (RF) devices. This study investigates the influence of rare earth (Sm+3) doping on structural and dielectric properties of strontium ferrite. Samarium doped strontium ferrite with composition Sr1-xSmxFe12O19(x=0.0,0.1,0.2,0.3) is prepared using the sol-gel auto combustion technique. The prepared samples' crystal structural and morphological properties were studied using an X-ray diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and RAMAN spectroscopy. XRD patterns of rare earth substituted strontium ferrite confirmed the formation of a hexagonal phase together with an impurity phase of Fe2O3 for x=0.3. FTIR analysis establishes metal and Oxygen (M-O) stretching vibrations in Sr1-xSmxFe12O19 due to various interstitial sites in its structure. The Raman result shows the presence of four Raman active modes in prepared powders. Meanwhile, the broadening of Raman peaks with Sm2+ doping is also observed. Electromagnetic properties were obtained in the frequency region 2-18 GHz. An increasing tendency is observed in the real part of permittivity and permeability of all doped samples in the frequency region 2-18GHz. The reflection loss was observed for sample x=0.2 with the maximum value of >-40dB at 18 GHz, and the adequate absorption bandwidth is 10 GHz from 8GHz to above 18GHz. On the basis of these results, among all prepared samples, Sr0.8Sm0.2 Fe12O19 is found to be the most suitable candidate for microwave absorbers.

Effect of Order of Reagents Addition on Optical and Structural Properties of CdS Quantum Dot Prepared by Chemical Bath Deposition Technique

Cadmium sulfide quantum dots were synthesized and deposited on glass substrates by chemical bath deposition (CBD) technique using cadmium sulfate and thiourea solutions in the presence of a 4,4’-(1,2-ethanediyldinitrilo)bis-(2-pentanone) (EDDBP) tetradentate ligand as a complexing agent. The order of reagents addition was varied to deposit films that were characterized for their surface morphological, optical, structural, and solid-state properties using a scanning electron microscope (SEM), a UV-visible spectrophotometer, an X-ray diffractometer (XRD), and Brunauer-Emmet-Teller (BET) analyses. The optimal condition for film deposition using the normal sequence of reagents addition was found at pH 8-12 and 298-353 ± 1K and gave films of 2.40-321.06 nm thickness, while the variation in the order of reagents addition gave improvements in the film properties. The optical properties and the observed direct band gaps (1.75-3.16 eV) of the films suggest usage in electroluminescent and solar cell devices since they have a first-order transition. The XRD patterns of the quantum dots indicated hexagonal wurzite structures, while the BET confirmed their mesoporous and nanonature.

Green synthesis of nanocellulose supported cu-bionanocomposites and their profound applicability in the synthesis of amide derivatives and controlling of food-borne pathogens

Copper bionanocomposites (CBNCS) were synthesized using Ipomoea carnea- sourced nanocellulose as support via an eco-friendly and cost-effective method. X-ray Diffractometer (XRD) pattern of CBNCS confirmed the octahedral structure of Cu2O, the face-centered cubic (FCC) crystal structure of Cu(0). XRD also revealed the crystal lattice of cellulose II. Surface Electron Microscope (SEM) and Transmission Electron Microscope (TEM) revealed the uniform distribution of copper nanoparticles (Cu NPs) with an average size of 10 nm due to the presence of nanocellulose. X-ray photoelectron spectroscopy (XPS) provided information about the electronic, chemical state and elemental composition of CBNCS. Thermogravimetric Analysis (TGA) showed the thermal stability of CBNCS. CBNCS catalyzed the rearrangement of oximes to primary amides in a very mild condition with a high yield of up to 92 %. CBNCS effectively inhibited the growth of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with lower minimum inhibitory concentration MIC values. Antioxidant activity and electrical conductivity of CBNCS were also determined.

Room temperature properties of microstructure and resistivity of alkaline earth – doped on lanthanide manganite

Microstructure of material has a strong relation with resistivity property. Here we report our interesting sample of La0.7(Sr1-xBax)0.3MnO3 (x = 0, 0.3, 0.6, and 0.9) material that has been synthesized by using sol-gel method successfully. All pattern of X-ray diffractometer (XRD) on the successful samples show that all samples are single phase confirmed without significant crystal disorder. The XRD pattern refinement yield that all samples formed R-3c space group with a rhombohedral structure. Although the substitution of Ba2+ to Sr2+ ions have significant difference in atomic radius; it does not change the crystal structure. However, the alkaline earth – doped on lanthanide manganite causes a change in lattice parameters which is followed by shifted of average crystal size, bond length, cell unit volume and bond angle at Mn-O-Mn. The microstructure results by means of scanning electron microscope (SEM) characterization shows that substitution of Ba2+ ions decrease the grain size and yield agglomeration. The relation on the microscopic result resistively confirmed by cryogenic magnetometer characterization in the concentration x = 0 has minimum resistivity of 1.28.10-3 Ωm and the maximum resistivity in the concentration x = 0.9 is 1.85.10-1 Ωm. The Ba2+ doped into Sr2+ in lanthanum manganite may cause a wider resistivity range.

Structural, optical and electrical properties of Al-doped CdO nanoparticles by solid state reaction

In the present study, aluminium doped cadmium oxide (Cd1-xAlxO) nanoparticles at (x = 0.00, 0.03, 0.05 & 0.07) concentrations were prepared using solid-state reaction and synthesized nanoparticles were subjected to different characterisations such as X-ray diffractometer (XRD), UV–Vis-Spectrophotometer (UV–Vis–NIR), field emission scanning electron microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and I–V measurements. The X-ray diffraction patterns confirm the polycrystalline nature of the Cd1-xAlxO nanoparticles with cubic structure. From the XRD patterns, the crystallite size and other structural parameters were calculated. The diffuse reflectance spectra were used to calculate the optical bandgap of the Cd1-xAlxO nanoparticles and it increased with increase of aluminium (Al) concentration (2.00 eV–2.04 eV). The FT-IR spectra confirm the Cd–O vibrational bands in the Cd1-xAlxO nanoparticles.The morphological studies revealed the spherical shape of the synthesized nanoparticles. The XPS spectra confirm the presence of aluminium (Al), cadmium (Cd) and oxygen (O) in the desired ratios. The current versus voltage characteristics of the Cd1-xAlxO nanoparticles were studied using Keysight source metre.

Study on magnetic and structural properties of Fe65Co35 soft magnetic alloy prepared by arc melting and subsequent annealing

Fe65Co35 based soft magnetic alloys (SMAs) have been gaining attention for their superior magnetic features and playing significant roles in composite permanent magnets, magnetic storage and automotive electrification technologies. In the present work, the Fe65Co35 alloy were produced by arc melting with subsequent annealing. The effects of arc melting and annealing upon the structural and magnetic properties of the soft magnetic phase of the alloy Fe65Co35 have been investigated. The variation in magnetic and microstructural characteristics with melting and annealing have been observed using the X-ray diffractometer (XRD), scanning electron microscope (SEM), and the vibrating sample magnetometer (VSM). The XRD patterns verified the existence of the Fe65Co35 alloy. After melting and annealing, the alloy surface morphologies were examined using SEM. In this approach, the Fe65Co35 alloy was annealed at 600 °C for 4 h in an argon environment which resulted in the highest saturation magnetization of 237 emu/g and the lowest coercivity of 31 Oe. The rise in saturation magnetization was attributed to the removal of impurities, during the melting and annealing process.

Structural and optical characteristics of Cu-doped CdS composite thin films

In this paper spin-coating method is used to create copper doped CdS composite thin films on glass substrates. Prepared Cux (CdS)1-x composite thin films, where x=1, 3 and 5 wt% Cu doped, have been characterised using an X-ray Diffractometer (XRD), scanning electron microscope (SEM) and UV-Visible spectrometer. These measurements provide the structural, morphological and optical properties of both pure and Cu doped CdS. The XRD pattern was used to examine the crystal structure and grain size of the CdS thin film. The optical spectra show absorption and band gap values of prepared samples. The band gap values have been found between 2.41 to 1.71. The photoluminescence (PL) spect rum emitted a strong peak approximately 430 nm which shows better optical quality for many applications.

Impact of Ca2+, Ce3+ codoping on ZnSnO3-SnO2 heterostructure for dielectric, optoelectronic and solar cell applications

We have successfully prepared a new mixed oxide system of Sn-rich ZTO (ZnSn2O5). The impact of coupling Ca2+ and Ce3+ inside the lattice of ZnSn2O5 on the dielectric, optical, and photoelectric conduction properties was investigated. In this regard, the co-precipitation technique was used to prepare three samples of ZTO, Ca-ZTO, and Ca/Ce-ZTO. The samples have been investigated by X-ray diffractometer (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscope (FESEM), X-ray photoelectron spectrophotometer (XPS), and an energy dispersive X-ray spectrometer (EDS). The XRD pattern detected phases that highly interfere as a heterostructured compound. The pristine ZTO particles demonstrate a mixture of two morphologies, hexagonal and quasi-spherical shapes, with particle size distributions of 0.25–1.5 µm, resulting in significant porosity between these particles. Meanwhile, the particles of Ca/Ce-doped ZTO have a homogenous morphology as spherical shape and exhibit larger density, particle size distribution range of 1–2 µm. The dielectric constant as a function of frequency or wavelength is increased with the applied temperature (32 to 140 °C) for both pure and Ca/Ce-ZTO samples. Clearly, Ca/Ce-ZTO displays higher absorption in visible light and the estimated band gaps of ZTO, Ca-ZTO, and Ca/Ce-ZTO are equal to 1.58,1.56 and 1.48 eV, respectively. The pristine ZTO showed a stronger n-type effect than Ca and Ca/Ce-doped ZTO samples. The shift from n-type to being close to N-P junction by multiple doping induces the application of these heterostructured materials as buffering layers in energy conversion applications like thin film solar cells and light emitting diodes.

Energy transfer and tunable-color luminescence properties of a single-phase CaSrNb2O7:Sm3+, Bi3+

New tunable-color luminescent materials are getting a lot of attention. Double-doped activated ions are an important research method. Here, CaSrNb2O7:R3+ (R3+ = Sm3+, Bi3+, and Sm3+/Bi3+) are synthesized by solid state method in the air. Phase purity and successful synthesis of samples are confirmed by X-ray diffractometer (XRD) patterns and energy disperse spectroscopy (EDS) diagram. The luminescence properties of samples are studied. CaSrNb2O7:Sm3+ has an excitation spectrum due to the O2- - Sm3+ charge transfer band (CTB) and the 6H5/2 → 4H9/2, 4D3/2, 4D1/2, 4F7/2, and 4I11/2 transitions of Sm3+ ion. The red-orange emission of CaSrNb2O7:Sm3+ is observed because of the 4G5/2 → 6H5/2, 6H7/2, 6H9/2, and 6H11/2 transitions of Sm3+ ion. PLE spectrum of CaSrNb2O7:Bi3+ comes from the metal-to-metal charge- transfer (MMCT) Bi3+ - Nb5+ and the 1S0 → 1P1 and 3P1 transitions of Bi3+ ion. CaSrNb2O7:Bi3+ shows blue emission due to the 3P1 → 1S0 transition of Bi3+ ion. The excitation spectrum of CaSrNb2O7:Sm3+, Bi3+ contains that of CaSrNb2O7:Bi3+ and CaSrNb2O7:Sm3+. CaSrNb2O7:Sm3+, Bi3+ with excitation at 314, 363, and 406 nm glows orange and red-orange, and red emission, respectively. We observe the energy transfer from Bi3+ to Sm3+ ions and the effect of Bi3+ on luminescence properties of Sm3+ ion by their spectra. The optimal Sm3+ and Bi3+ concentrations are confirmed by the concentration dependent spectra. The energy level diagrams of Sm3+ and Bi3+ are used to analyze the luminous mechanism. The results are conducive to the development of new Sm3+ and Bi3+ co-doped luminescent materials.

Niobium doping effect on electrical and optical properties of ZnO nanorods produced by ultrasonic spray pyrolysis

Niobium metal doped ZnO nanorods were fabricated on a glass substrate using an ultrasonic spray pyrolysis system in two steps. The structural, morphological, and optical properties of the produced samples were investigated via an x-ray diffractometer (XRD), a field emission scanning electron microscopy (FE-SEM) combined with energy dispersive x-ray spectroscopy (EDX), and a spectrophotometer, respectively. The XRD patterns were indexed in the hexagonal (wurtzite) unit cell type for all the ZnO samples. In addition, according to the XRD peaks, the crystals grew in the c-axis (002) direction. The morphological features of the obtained thin films were examined. From the SEM micrographs, it was observed that ZnO thin films doped with Nb had a nanorod structure in the c-axis direction. The presence of Nb ions in the samples was proved via EDX analysis. The electrical conductivity values of the pristine and 10 % mol Nb-doped ZnO samples were 3.16 x 10−9 and 3.98 x 10−7 (ohm−1.cm−1) at 25 °C; and 7.08 x 10−7 and 5.01 x 10−5 (ohm−1.cm−1) at 300 °C, respectively. The optical transmittances of the samples were measured at wavelengths of 350–1000 nm. It was observed that the produced films had high optical transparency. The average optical transmittance value of the samples was 90 %.

Utilization of Ferrate Ion (FeO42-) as Oxidizing Agent for Reducing Color Intensity of Peat Water

Peat water from Central Kalimantan is generally yellow to brownish-red in color. It causes peat water to not be used as a source of water for daily needs. Humic acid, fulvic acid, and humin are organic compounds that cause peat water to become colored. One alternative step that can be taken for reducing the color intensity of peat water is to degrade color-causing organic compounds by using an oxidizing agent. A hexavalent form of iron ion (Fe6+), commonly called ferrate (FeO42-) in potassium ferrate compound, is a powerful oxidizing agent used in the present study. Potassium ferrate (K2FeO4) was synthesized by a wet oxidation method and characterized using a UV-Vis spectrophotometer and an X-Ray Diffractometer (XRD). The ferrate solution is purplish-red in color with a maximum wavelength of 510 nm. The XRD pattern shows strong diffraction peaks at 2θ which are characteristic of K2FeO4. The ferrate solution was then used to degrade color-causing organic compounds in the peat water from Central Kalimantan. Determination of the optimum degradation conditions was monitored by the absorbance decrease of organic compounds in peat water at a wavelength of 370 nm. The results showed that ferrate solution with a concentration of 80 ppm was able to degrade organic compounds in peat water at pH 8, with a removal efficiency of 100%. Keywords: oxidizing agent, ferrate ion (FeO42-), peat water

Annealing Effect on Nickel Oxide Nanoparticles Properties

Abstract: Sodium hydroxide and nickel chloride have been used in the effective chemical precipitation process to create nickel oxide (NiO) NPs. We investigate how the morphological, structural, magnetic, and optical characteristics of nanocrystalline NiO are affected by annealing at temperatures of 300, 400, and 500 °C. Field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and ultraviolet-visible (UV-vis) spectrophotometer have been utilized in order to characterize NiO-NPs. XRD pattern indicates the material's excellent crystallinity. At the same time, the FESEM study of the synthesized samples reveals that the annealing temperature has a considerable impact on the films' surface morphology. The average crystallite size of NiO samples falls within the range of 29–30.9 nm., whereas the average grain size of synthesized NiO-NPs, as determined by FESEM images, is between 25 and 29.6 nm. We demonstrate that as the annealing temperature rises, grains’ average size increases, but their shape remains spherical. In addition to that, the UV-Vis spectroscopy analysis shows the particles’ significant absorption peak in the UV region. Our investigation reveals that the synthesized samples have direct band gaps. Before annealing, the energy gap measures 2.4 eV; however, by raising the annealing temperature, we were able to attain a broader range of band gap energies for NiO-NPs, with values spanning between 4.05 and 4.95 eV. The created NiO-NPs demonstrate superparamagnetic behavior, which was found in the VSM results examination. Keywords: Nickel oxide nanoparticles, Annealing, Chemical precipitation, Magnetic properties.

Using pomegranate peel extract green synthesize of AG nanoparticles: characterization and antibacterial activity

In this research, the eco-friendly biogenesis of silver nanoparticles from 2 mM AgNO3 using the extraction of pomegranate peel (EPP) as the agent of reduction was explored. Analysis of the Fourier transform infrared spectrum (FT-IR), UV-visible spectrum, and scanning electron microscopy (SEM) were used to characterize Ag nanoparticles. At 425 nm, UV-visible spectra show a significant resonance on the surface of silver nanoparticles (AgNPs). A spectrum investigation using FTIR spectroscopy revealed that EPP operated as a reduction agent. SEM analysis reveals nanoparticles with average particle sizes ranging between 30 and 50 nm. AgNPs' antibacterial activity was also tested against Staphylococcus aureus. X-ray diffractometer (XRD), using Scherrer's equation and the refraction peak in the XRD pattern, the average particle diameter of the silver nanoparticles was determined to be 80. The silver nanoparticles formed in the brown-colored stable samples according to SEM analysis, and well-dispersed nanoparticles could be seen in the silver nitrate-treated samples. Ag nanoparticles produced by pomegranate peel extract show the maximum antibacterial activity against S. aureus (0.1, 0.2, 0.3 and 0.4 mol). This technique produces Ag NPs with effective antibacterial action against harmful microorganisms. One of these is silver nanoparticles, which have a substantial influence on nanotechnology and the field of nanomedicine.

Antibacterial studies and characterization of newly synthesized ZnO/ZnS/CuS ternary nanocomposite

A nanomaterial is a substance that is nano scale-sized (1–100 nm). This substance is highly valuable for commercial uses and has special features. The development of new antibiotic medications to regulate and stop the spread of bacterial strains appears to be a viable application for transition metal base nano composites. In the creation of new pharmaceuticals, the ternary nano composite may play an important role in the production of diverse antibacterial drugs. The X-ray diffractometer, Fourier Transform infrared spectrophotometer, and UV–visible spectrophotometer were used to characterize the ZnO/ZnS/CuS ternary nano composite, which was effectively manufactured utilizing the cation exchange process. In light of this, the major peak on the X-ray diffractometer patterns of the ZnO/ZnS/CuS ternary nano composite's crystallite size was determined. The presence of Zn-O symmetric stretching vibrations at 442 cm−1 and 809 cm−1 in the Fourier Transform Infrared spectrum, caused by weak ZnO vibration, and another peak at 687 cm−1 caused by Zn-S symmetric bending vibration, which demonstrated the development of ZnO/ZnS nano composite material. The production of the ZnO/ZnS/CuS ternary nano composite was demonstrated by the additional peaks at 1107 cm−1 and 618 cm−1 attributed to C-O stretching and CuO, respectively. The band gap energy of the ternary nanocomposites ZnO/ZnS/CuS was determined using a UV–visible spectrophotometer. Finally, using the paper disc diffusion technique, the antibacterial properties of the produced nanomaterial were investigated against Gram-positive (Staphylococcus aureus and Streptococcus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Gram-positive bacteria are more resistant to the ZnO/ZnS/CuS ternary nano composite's antibacterial effects than Gram-negative bacteria.

Photocatalytic degradation of naphthol blue from Batik wastewater using functionalized TiO2-based composites

This work provides a first-time comparative study examining the photocatalytic activity of functionalized TiO2-based composites to eliminate naphthol blue in Batik wastewater. Reduced graphene oxide (RGO) was synthesized by oxidizing solid graphite using the Hummers' method followed by sonication and reduction. N-doped TiO2 (N–TiO2) was synthesized from titanium tetrachloride (TiCl4) and urea (CH₄N₂O) precursors by the sol-gel method. N–TiO2 modified RGO (RGO/NT) was synthesized using a hydrothermal method from N–TiO2 and RGO. Prepared TiO2-based composites and commercial TiO2, for comparison were characterized using Fourier transform infrared spectrometer (FTIR), X-Ray diffractometer (XRD), scanning electron microscope-energy dispersive X-ray (SEM-EDX), and UV–Vis diffuse reflectance spectrometer (UV–Vis DRS). FTIR characterization indicated Ti–N bonding in N–TiO2 and RGO/NT. XRD patterns showed that commercial TiO2 had a rutile phase, while N–TiO2 and RGO/NT had an anatase phase with crystal sizes of 30.09, 16.28, and 12.02 nm, respectively. SEM results displayed the presence of small and glossy white N–TiO2 dispersed on the surface of RGO. Characterization using UV–Vis DRS showed that the band gap energy values for TiO2, N–TiO2, and RGO/NT were 3.25, 3.12, and 3.08 eV with absorption regions at the wavelengths of 382, 398, and 403 nm, respectively. The highest photocatalytic activity for RGO/NT for degrading naphthol blue was obtained at pH 5, with a photocatalyst mass of 60 mg, and an irradiation of 15 min. Photocatalytic degradation by RGO/NT on Batik wastewater under visible light showed higher effectivity than under UV light.

Luminescence properties of multicolor-tunable emitting LiYGeO4: Tb3+, Eu3+ phosphors with excellent thermal stability for WLEDs

In order to investigate the impact of rare earth (Tb3+/Eu3+) ion doping on the luminescent properties of LiYGeO4, a series of LiYGeO4: 30%Tb3+, yEu3+ (0.0% ≤ y ≤ 1.0%) phosphors were successfully prepared using the solid-state reacthion in this work. The analysis revealed that Tb3+/Eu3+ ions were successfully doped into the LiYGeO4 lattice, confirmed by of X-ray diffractometer (XRD) patterns, Rietveld refinement, and element distribution results. The LiYGeO4: 30%Tb3+, yEu3+ samples exhibit efficient excitation by both ultraviolet (378 nm) and blue light (482 nm). Furthermore, the luminescence intensity, quantum yield, and thermal stability under 378 nm excitation were found to be greater than those under 482 nm excitation. Increasing the concentration of Eu3+ ion doping resulted in an energy transfer from the green region to the yellow region and finally to the orange red region, as evidenced by the Commission Internationale de L′Eclairage (CIE) coordinates of LiYGeO4: 30%Tb3+, yEu3+ phosphors. The white light emitting diodes (WLEDs) prepared utilizing LiYGeO4: 30%Tb3+, 0.75%Eu3+ phosphor shows a high color rendering index (Ra) of ∼93.2, a low correlated color temperature (CCT) of 5134 K, emitting bright natural light. This study helps to understand the mechanism of energy transfer, improves the luminescent material system of LiYGeO4, and provides new ideas and options for designing a high-performing lighting sources.

Influence of Inter-Molar Concentration of Cu and Zn on the Various Properties of Sprayed Nano-Crystalline Cu2ZnSnS4 Thin Films

In this work, the quaternary nanostructured Cu2ZnSnS4 (CZTS) thin films were deposited on ITO glass substrates at a temperature of 300[Formula: see text]C by spray pyrolysis method and the influence of inter-molar concentration variations of copper and zinc on the structural, morphological and optical properties of grown samples was studied. The films were characterized by different sophisticated techniques including X-ray diffractometer (XRD), scanning electron microscopy (SEM), Raman spectroscopy and UV–Vis spectroscopy. The solitary presence of kesterite tetragonal phase with favored orientation along (112) plane is confirmed by XRD patterns and Raman spectroscopy. However, due to the variation in lattice parameters, a moderate shifting in (hkl) planes was observed. SEM micrographs and EDAX analysis showed the uniform morphology of the so-grown CZTS films covered with nanoplates of different sizes and the ionic compositional variation of the precursor solution matches with the elemental variation in the grown samples. A minor nonstoichiometry in chemical composition ratio [Formula: see text] from 0.74 to 1.24 was noticed in the films. Optical studies of CZTS films showed that these films possess optical band gap ranging from 1.45[Formula: see text]eV to 1.60[Formula: see text]eV.

Incorporation and solidification mechanism of manganese doped cement clinker.

Using municipal and industrial solid waste as a substitute raw material and fuel in cement rotary kiln co-processing is considered an economic and environmentally friendly alternative to the use of traditional fuels. However, the presence of heavy metals in solid waste is a growing concern in the cement rotary kiln co-processing technique. The solidification mechanism of heavy metals in cement clinker is directly related to their stabilization. Cement clinkers doped with manganese oxide (MnO2: 0.0%-5.0% wt%) were prepared in a laboratory to investigate the impacts of extrinsic Mn on cement clinker calcination. The insignificant changes in X-ray diffractometer patterns indicated that the fixed Mn had little influence on the mineral lattice structure. Raman spectra and X-ray photoelectron spectroscopy revealed the transformation of the silicate phase when the Mn dose was increased. Moreover, the satisfactory solidification ratio confirmed the incorporation of Mn in the cement clinker. These results provided evidence of the influence rule of Mn in the cement clinker calcination process. Furthermore, Raman spectroscopy showed great potential for the qualitative and semi-quantitative analysis of the cementitious materials derived from cement rotary kiln co-processing. These results will be important for the further development of green cement manufacturing technology.