Prominent Diffraction Peak Research Articles

Photocatalytic and adsorption behavior of a new efficient LaxNiyMn3–(x+y)O4/SiO2 composite for environmental remediation application

Environmental remediation of organic contaminants has recently received significant attention, necessitating the development of energy-efficient, cost effective, and environment-friendly catalysts. In this study, novel dual-doped LaxNiyMn3–(x+y)O4 nanoparticles (NPs) and their composite with an adsorptive material (mesoporous silica) were synthesized using a low-cost, environment-friendly coprecipitation technique. The as-prepared LaxNiyMn3–(x+y)O4 NPs and their composite were studied via X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), Fourier-transform infrared (FTIR) spectroscopy, and ultraviolet–visible spectroscopy. XRD analysis revealed that the LaxNiyMn3–(x+y)O4 NPs possessed a crystalline structure. FESEM showed that LaxNiyMn3–(x+y)O4 NPs were spherical with diameters ranging from 60 to 100 nm. The presence of metal–oxygen bonds in the LaxNiyMn3–(x+y)O4 NPs was confirmed by FTIR analysis. The LaxNiyMn3–(x+y)O4 NPs could degrade crystal violet (CV) dye under visible light with a percentage degradation of 82%, which increased to 92% with the addition of 0.5 mL of 6% H2O2 solution. Furthermore, to increase the adsorption ability of the LaxNiyMn3–(x+y)O4 NPs, a composite LaxNiyMn3–(x+y)O4/SiO2 was synthesized. Under dark conditions, the adsorption percentage of the LaxNiyMn3–(x+y)O4 NPs was 58%, whereas that of LaxNiyMn3–(x+y)O4/SiO2 reached 73%. The adsorption process was further explored using adsorption isotherms and reaction kinetic models. The central composite rotatable design of response surface methodology was used to statistically maximize the adsorption of CV by optimizing factors such as time (40 min), pH (8.68), and composite dose (12 mg). The prominent diffraction peak in the XRD pattern and the large surface area (532 m2/g) determined via Brunauer–Emmett–Teller analysis of the composite confirmed its unique porous characteristics, illustrating its high capacity for adsorbing pollutants inside the porous network. Studies on the degradation efficiency and adsorption–photocatalysis synergy suggest the substantial potential of the synthesized composite for application in environmental remediation.

Impact of the Ni/Co ratio on structural and magnetic properties in A-site stoichiometric nanosized spinel ferrites

We present a meticulous synthesis of Co1-xNixFe2O4 nanoparticles (0.0 ≤ x ≤ 1.0) via the chemical citrate precursor technique. Comprehensive X-ray diffraction (XRD) analyses showcased prominent diffraction peaks, especially for the x = 0.0 sample, corroborating the impeccable cubic spinel ferrite structure devoid of extraneous phases. This structural integrity is further evidenced by a linear attenuation in unit cell parameters with heightened Ni2+ ion concentration, a phenomenon seamlessly aligning with Vegard's law and the nuances of the A-site ionic radii. Magnetic characterizations derived from Vibrating Sample Magnetometer (VSM) evaluations reveal a pronounced modulation in primary magnetic parameters with increasing Ni content. This modulation not only resonates with the charge and spin dynamics of the A-site ions but also accentuates the cardinal role of cation distribution between A- and B-sites in magnetic property determination.

Mechanosynthesis of semiconductor nanocrystalline Cu2ZnSnSe4 for solar cells

Cu2ZnSnSe4 is a promising material that can be used to make low-cost, high-efficiency thin-film solar cells. The present study, we established a simple and efficient approach for producing a single-phase Cu2ZnSnSe4 bulk material from fundamental precursors (Cu, Zn, Sn and Se) using dry ball milling. After every two hours of the dry milling process, X-Ray Diffraction (XRD) and Raman Spectroscopy investigations were carried out to investigate the movement towards single phase Cu2ZnSnSe4 and the concurrent secondary phase depletion. The development of Cu2ZnSnSe4 materials that crystallize in a Kesterite system is shown by the prominent diffraction peaks. The crystalline size of the materials is 10–20 nm and dislocation density is 3.02–3.22 ×1015 lines/m2. UV–Vis spectroscopy was used to investigate the optical properties of the materials. Using transmittance and reflectance data, the linear and nonlinear optical constants of Cu2ZnSnSe4 films were calculated and the bandgap value is 1.6 eV. Hence from these results we can conclude that the above synthesized powder can be used for the development of thin films via thermal or electron beam evaporations on desired substrate and also we can use for various energy harvesting applications as a photoabsorber.

Investigation of the Evolution of the Chemical Structure of Bituminous Coals and Lignite during Pyrolysis

This paper aims to investigate the evolution of the chemical structure of coal char during pyrolysis. Two bituminous coals (coals A and B) and one lignite (coal C) were pyrolyzed in a fixed bed in N2 from 600 °C to 1100 °C. The chemical structure of coal char was characterized by Raman spectroscopy and X-ray diffraction (XRD). The carbon and oxygen functionalities of coal char were analyzed by X-ray photoelectron spectroscopy (XPS). The Raman spectroscopic parameters AD/AG (AD1/AG, AD2/AG, and AD3/AG) increased from 600 °C to 900 °C and then decreased after 900 °C, indicating that the degree of order of coal char first decreased and then increased with increasing pyrolysis temperatures (600–1100 °C). The content of graphite-like microcrystalline carbon decreased and then increased with an increase in temperature. Prominent diffraction peaks of microcrystalline carbon for coal chars A and B were observed, but only minerals were shown in diffraction patterns of coal char C since the ash content of coal chars A and B is much lower that that of coal char C. The lateral size of the crystallite plane (La) generally increased between 600 °C and 1100 °C. The relative content of C=O and COOH in coal chars A and B generally decreased as the temperature increased, suggesting an increase in the degree of order at higher temperatures. The oxygen functionalities of coal char were composed of organic oxygen and oxygen-containing bonds of minerals.

Self-Assembly Ultrathin Fe-Terephthalic Acid as Synergistic Catalytic Platforms for Selective Hydrogenation

Self-Assembly Ultrathin Fe-Terephthalic Acid as Synergistic Catalytic Platforms for Selective Hydrogenation

A novel electrochemical synthesis of graphene oxide: Converting waste product to utility

We comprehensively report here a green route for synthesizing graphene oxide (GO) from waste Zn-C dry cell batteries. Here LiCl was used as electrolyte for the electrochemical synthesis of GO from graphite rods extracted from waste batteries. The satisfactory yield of 0.0305 g/h, formulated wholly through basic medium (at pH 9.36), was validated through confirmatory characterizations such as X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FTIR), UV-Vis and Raman spectroscopy, etc. A prominent diffraction peak around 26.70° in the XRD spectra and two prominent excitonic peaks around and in the Raman spectra were observed for the obtained samples. The overall scheme turned out to be engaging less reactants as well as facile; thus, converting a waste material to a useful product.

Synthesis and characterization of native and modified bitter yam starch grafted with acrylonitrile

This analysis studied the effects modification on the properties of starch-based polymer grafted with acrylonitrile (copolymers). Starch was extracted from bitter yam. The starch was modified by heating the solution above 70 °C and then esterified with phthalic anhydride to produce a pregelatinized phthalated derivative. Acrylonitrile was grafted onto natural and pregelatinized phthalated starch at 120 °C using calcium oxide from snail shell as the initiator. The grafting reaction of starch with poly(acrylonitrile) and the phthalation of the starch were both confirmed by Fourier transform infrared (FTIR). Scanning electron microscopy analysis revealed changes in the morphology of the pregelatinized phthalated grafted copolymers. The X-ray diffractogram showed that native starch grafted copolymer displayed broad diffraction peaks (amorphous), but the phthalated bitter yam starch grafted with acrylonitrile had prominent diffraction peaks (crystalline). Thermogravimetry analysis revealed that the phthalated grafted copolymer has better thermal stability than the native grafted copolymer.

Reaction kinetics of the thermal decomposition of MAPbI3 thin films

Despite their outstanding optoelectronic properties, metal halide perovskites have not yet seen widespread use in commercial applications. This is mostly due to their lack of stability with respect to several external factors, e.g., humidity, heat, light, and oxygen. Even though extensive studies have been carried out over the last decade, a lot of questions regarding their thermal stability still remain, and various publications have put forth different approaches for measuring and quantifying the conditions of their decomposition. However, differences in the experimental setups and in the reported values make comparisons of the reported results challenging. We show an approach, where ${\mathrm{MAPbI}}_{3}$ thin films are thermally decomposed in high vacuum within a temperature range from $220{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$ to $250{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$, while monitoring changes in the crystal structure using an in situ x-ray diffraction setup. This process reveals the complete phase evolution of the thin films from ${\mathrm{MAPbI}}_{3}$ into ${\mathrm{PbI}}_{2}$. The time resolved data was then evaluated in view of the reaction kinetics using three different approaches. First, an Arrhenius fit was applied to $lnk$ over $1/T$, where the rate constant $k$ was determined by fitting a first order exponential decay onto the decreasing peak area of the most prominent diffraction peaks. Secondly, a model fitting approach was used, where the data was tested against a set of different reaction models. Lastly, a model free isoconversional approach was applied. By doing this, we succeed in characterizing the decomposition and determine the kinetic triplet, consisting of the activation energy $E$, the frequency factor $A$, and the reaction model $f(\ensuremath{\alpha})$. With the help of the kinetic triplet the decomposition reaction can be expressed in a physically meaningful way and allows us to predict the decomposition dynamics of ${\mathrm{MAPbI}}_{3}$ thin films for varying temperatures.

Evolution of Monoclinic CaAl2O4 Nanocrystallites via Chemical Route and Its Optical Investigations

Nanocrystalline calcium aluminate (CaAl2O4) powder is an adequate phosphor material. Calcium aluminate is a versatile member belongs to a category of alkaline earth aluminates phosphor. It has multifaceted applications in different areas such as photocatalysis, sensing, optoelectronic devices, displays, and imaging etc. In the present study, calcium aluminate has been prepared by well-known citrate sol-gel technique. X-ray diffraction (XRD) method has been used to analysis the amorphous and crystalline behavior of the prepared samples. The sample annealed at 800° indicates the monoclinic phase with enhanced intensity of the prominent diffraction peaks. By using Debye-Scherrer formula the grain size of crystalline powder is calculated ~10 nm. FTIR spectra confirmed the molecular orientation and bond structure in the prepared nanomaterial. Surface morphology and elemental composition present in prepared samples has been examined by Scanning electron microscope and energy dispersive spectroscopy. Uv-vis spectroscopy result showed red shift in the nanopowder with thermal treatment. In material science, due to their long-lasting photo-luminescence properties in visible region these aluminates are very attractive for evolution of new generation inorganic phosphor materials.

Study of photodegradation and wetting behavior on synthesis oxides of tin (stannous and stannic)

Amongst the varieties of metal oxides, tin oxides semiconducting are particularly interesting because of their promising nature as catalyst, energy harvesting, water purification, electronics device and space applications. In this study, three synthesized methods (air thermal oxidation, aqueous and non-aqueous) were adopted to explore the properties and application of stannous oxide (SnO) and stannic oxide (SnO2). Tin oxide materials were characterized through different techniques such as scanning electron microscopy (SEM), ultraviolet visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy and photoluminescence. The optical microscopy and electron microscopy images show the morphology of the tin oxide. The percentage of tin and oxygen from the elemental analysis was ~ 55% and 44 wt% respectively. FTIR spectra confirmed the Sn–O functional from the vibration peak. XRD pattern shows the prominent diffraction peak which indicates the state of oxidation of tin oxide and crystallinity. A photodegradation activity was tested in the tin oxide sample with methylene blue to explore how tin oxide surface features absorb the integrity of a dye and degrade in the presence of sunlight. The tin oxide solution emits green fluorescence in the UV light, depending upon its concentration. The water droplet contact angle measured on the tin oxide film which was experimentally observed as 69°. The theoretically wetting behavior was also studied on a tin oxide with the effect of substrate by molecular dynamics. The results suggest that material can be utilized as a photo-catalyst, drug delivery and thin-film application of solar cells.

The influence of deposition gases on the material properties of Y2SiO5: Ce3+ thin films deposited by pulsed laser deposition (PLD) method

The material properties of Y2SiO5: Ce3+ thin films have been investigated. The X-ray powder diffraction (XRD) analysis shows that the films are structurally monoclinic with the most prominent diffraction peak of 15.7 °. The maximum crystallize size was obtained for samples deposited under oxygen deposition. The PL emission peaks are observed at 423 nm when probed at 370 nm, which can be ascribed to the transition of the electrons from the excited state of 5d to the ground state of 4f. Due to the spin–orbit interactions, the 4f ground state splits into 2f5/2 and 2f7/2 energy sub-levels. The scanning electron microscopy (SEM) measurement shows a rough and uniform distribution of grains with small agglomerated topographic areas. The energy dispersive spectroscopy (EDS) measurements shows the presence of all elements (Y, Si, O, and Ce). The maximum and minimum absorbance of the visible ultraviolet (UV–vis) spectrum was observed for the thin films deposited under the Argon and vacuum atmospheres with small shifts from Argon to the other depositions. The energy bandgap varies between 3.14 and 4.33 eV. The CIE measurement gives the blue emission band at an emission wavelength of 423 nm. The activation energy was obtained in the range of 0.1733 and 0.1938 eV. The maximum activation energy was obtained under the argon gas deposition.

Wetting and Photocatalytic Behavior of Two-Dimensional Tin Oxides

Among the variety of two-dimensional oxides, tin oxides semiconducting are particularly interesting because of their promising in catalyst, energy harvesting, water purification, electronics device and space applications. In this study, three synthesized methods use adopted to explore the properties and application of oxides of tin sheets. The methods are air oxidation, aqueous and non-aqueous which characterized through techniques such as SEM-EDS, UV -spectroscopy, X ray diffraction, FTIR and photoluminescence. From SEM image showed the morphology of the tin oxide materials. The percentage of tin and oxygen from elemental analysis was ~ 55 % and 44 % respectively. FTIR spectra confirmed that Sn-O functional from the vibration peak. The X- ray diffraction pattern shows that prominent diffraction peak which indicates formation of tin oxide crystallinity. A photoabsorbtiy activity was tested in the tin oxide sample with methylene blue to explore how the tin oxide surface featured absorbs the integrity of a dye. Porosity and a surface alteration resulted in a increase in photoactivity. The tin oxide sheets emit green fluorescence in the UV light and emission might be dependent on the number of layers and concentration of it. The water droplet contact angle measure on the tin oxide sheets which is experimentally observed 69°. The theoretically molecular dynamics-based contact angle measurement was also studied on monolayer of stannous oxide, stannic oxide with effect of substrate. Based on above results, this material can be utilized as a photo-catalyst, drug delivery and thin film application of solar cell.

Effect of ZnO dispersion in optical and structural of nematic liquid crystal

Incorporation of zinc oxide (ZnO) semiconductor particles in liquid crystal technology is advantageous due to its unique optical properties especially in ultraviolet region. In this paper, optical and film morphology of nematic liquid crystal films, 4′-(hexyloxy)-4-biphenylcarbonitrile (6OCB) were analyzed using UV-Vis absorption spectroscopy, z-scan measurement, Raman spectroscopy and X-ray powder diffraction. As expected, dramatic change of absorption in both ultraviolet and visible region were observed upon additional weightage of ZnO particles into the 6OCB mixture. Z-scan measurement obtained under 532 nm CW laser line was used to study nonlinear refractive index, n2 of the material. This ZnO particles incorporation in 6OCB mixture show self-defocusing property with thermal effects as one of its origin of nonlinear absorption occurring at 532 nm. Prominent diffraction peaks of 15°, 29°, 31°, 35° and 47° were measured from rubbed films of 6OCB doped ZnO films which indicated 6OCB and ZnO lattice crystal structures. Microscopic formations of 6OCB molecules is highly dependent with the proximity to the ZnO particle as analyzed by Raman vibrational analysis. These findings can be used to suggest optical and electrical improvement to the liquid crystal film in optoelectronics application as electro-optic modulator and optical switch.

Effect of substrate temperature on the material properties of the Y2SiO5: Ce3+ thin film by pulsed laser deposition (PLD) method

The effect of substrate temperature on the material properties Y2SiO5: Ce3 + thin film deposited by the pulsed laser deposition method reported. The deposition temperatures used are room temperature, 150, 250, 350, 450 and 6000 C. XRD analysis shows that the average crystallite size is about 1.66 nm. The material is monoclinic in structure with the most prominent diffraction peak at 29.20. An increment in surface thickness was observed as the deposition temperature increases from 150 to 450° C and decreases from 450 to 600° C. The decrease in surface thickness ascribes to a reduci.tion in deposition rate. The main photoluminescence (PL) emission peak was observed at 465 nm, which is attributed to the electronic transition from 5d → 4f of the Ce3+orbitals. The excitation peak was detected at 337 nm, which can be attributed to the transition of an electron from the ground state (2F5/2) to the excited state (5d) of Ce3+. The highest emission intensity occurs with an excitation wavelength of 337 nm for all deposition temperatures. The maximum decay time was observed at a deposition temperature of 4500 C. The CIE was deployed at an emission wavelength of 465 nm, and the blue color is the corresponding color. The maximum ultraviolet-visible spectrum (UV–vis) absorbance was observed at around 337 nm. The scanning electron microscope (SEM) images show that, the morphology changes as the substrate temperature changes. The Energy Dispersive X-ray Spectrometer (EDS) shows the presence of all the elements of the compound matrix (Y, Si, O, and Ce) with their respective atomic weights.

Pine shaped InN nanostructure growth via vapour transport method by own shadowing and infrared detection

We have demonstrated the synthesis of Indium Nitride (InN) Nanopines (NПs) array on Si substrate using Oblique Angle Deposition (OAD) technique. The deposited InN NПs have an average height of ∼2 μm. The grown InN NПs are hexagonal in nature and have prominent diffraction peak along <002> orientation. The X-ray photoelectron spectroscopy (XPS) measurement confirms the presence of InN bonds. An Optical absorption spectroscopy reveals high band gap absorption at approximately 1.15 eV. The carrier concentration of (∼1.8 × 1020 cm−3) was determined using capacitance (C) – voltage (V) measurement. The infrared detection with maximum responsivity at 1.14 eV (∼1078 nm) was obtained near the optical band edge at 10 K. A low device sensitivity was observed with an increasing operating temperature.

Formula omitted] nanocrystals under glycine nitrate combustion formation

Nanocrystalline perovskite NdFeO3 with the orthorhombic structure was prepared by a glycine nitrate combustion method under different technological conditions. The starting materials Fe(NO3)3·9H2O,Nd(NO3)3·6H2O in stoichiometric amounts and H2NCH2COOH were used. These quantities were varied by changing the ratio of glycine moles to metal nitrate moles (G/N) in the range between 0.25 and 0.75. The prepared NdFeO3 nanocrystals were characterised by X-ray diffraction (XRD) and electron microscopy. Decomposition of the XRD diffraction profile using Voigt contours was exploited for analysis of the pattern in the area where the most prominent diffraction peak was situated. We demonstrate that Voigt functions reduce to Lorentzians for G/N=0.75 and 0.55. A volume-weighted diameter distribution function was derived using the width of the Lorentzians. The log-normal shape of the distribution is discussed in terms of the model, assuming exponential growth of cluster size in the time available for the NdFeO3 nanograin to grow.

Solution-processed interlayer of n-type small molecules for organic photovoltaic devices: Enhancement of the fill factor due to ordered orientation

Novel alcohol/water-soluble small molecules were obtained using various p- and n-type backbones. The synthesized molecules were dissolved in organic solvents and highly polar solvents. The DPPA film exhibited strong shoulder peak at approximately 633nm compared with the solution, which was due to the ordered orientation of DPPA. According to XRD measurements, a prominent diffraction peak at 20.1° was observed in the in-plane diffraction pattern of DPPA, which indicates an out-of-plane peak (010) due to the molecular packing by π–π stacking. A photovoltaic device containing DPPA exhibited an open-circuit voltage of 0.75V, a current density of 15.1mA/cm2, a fill factor of 69.0% and a power conversion efficiency of 7.9%. The photovoltaic device containing the DPPA derivative exhibited an improved power conversion efficiency compared with those containing BPA and QA (6.6% and 7.6%, respectively) due to the ordered orientation and packing of DPPA.

Synthesis of gallium nitride nanostructures by nitridation of electrochemically deposited gallium oxide on silicon substrate.

Gallium nitride (GaN) nanostructures were successfully synthesized by the nitridation of the electrochemically deposited gallium oxide (Ga2O3) through the utilization of a so-called ammoniating process. Ga2O3 nanostructures were firstly deposited on Si substrate by a simple two-terminal electrochemical technique at a constant current density of 0.15 A/cm2 using a mixture of Ga2O3, HCl, NH4OH and H2O for 2 h. Then, the deposited Ga2O3 sample was ammoniated in a horizontal quartz tube single zone furnace at various ammoniating times and temperatures. The complete nitridation of Ga2O3 nanostructures at temperatures of 850°C and below was not observed even the ammoniating time was kept up to 45 min. After the ammoniating process at temperature of 900°C for 15 min, several prominent diffraction peaks correspond to hexagonal GaN (h-GaN) planes were detected, while no diffraction peak of Ga2O3 structure was detected, suggesting a complete transformation of Ga2O3 to GaN. Thus, temperature seems to be a key parameter in a nitridation process where the deoxidization rate of Ga2O3 to generate gaseous Ga2O increase with temperature. The growth mechanism for the transformation of Ga2O3 to GaN was proposed and discussed. It was found that a complete transformation can not be realized without a complete deoxidization of Ga2O3. A significant change of morphological structures takes place after a complete transformation of Ga2O3 to GaN where the original nanorod structures of Ga2O3 diminish, and a new nanowire-like GaN structures appear. These results show that the presented method seems to be promising in producing high-quality h-GaN nanostructures on Si.

Thickness effect on the band gap of magnetron sputtered Pb45Se45O10 thin films on Si

Oxygen doped PbSe thin films with different thickness were grown on the Si (100) substrates by magnetron sputtering, and characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and physical properties measurement system. As the film thickness increased, the intensity of the (200) PbSe prominent diffraction peak increased, while the (220) peak almost vanished, indicating the primary growth direction. The change rate between the light and dark resistance increased with the film thickness, and the maximum of 64.76% was obtained. According to the density functional theory calculations and the experimental results, the band gap of the PbSe thin films decreased from 0.278eV to 0.21eV when doped with oxygen. Doping with oxygen during the deposition process is a viable way to prepare PbSe thin films with a tunable band gap. The band gap increased almost linearly with the lattice constant, confirmed by the calculated and experimental results.

Temperature dependence of structure and density for D2O confined in MCM-41-S

Using neutron diffraction, we have tracked the temperature dependence of structural properties for heavy water confined in the nanoporous silica matrix MCM-41-S. By observing the correlation peak corresponding to the pore–pore distance, which is determined by the scattering contrast between the silica and the water, we monitored the density of the confined water. Concurrently, we studied the prominent first diffraction peak of D2O at ≈1.8 Å−1, which furnishes information on the microscopic arrangement of the water molecules. The data show the presence of a density maximum at ≈275 K (±10 K), a property similar to bulk water, and the occurrence of a density minimum at ≈180 K (±10 K). The prominent diffraction peak of D2O is found to shift and sharpen over a wide T range from 200 to 270 K, reflecting structural changes that are strongly correlated with the changes in density. We also observe the continuous formation of external ice, arising from water expelled from the pores while expansion takes place within the pores. An efficient method for monitoring the density of the confined D2O using a triple-axis spectrometer is demonstrated.