Crystallite Size Of Nanoparticles Research Articles

Structural, morphological and electrical properties of hydrothermally synthesized cobalt disulfide (CoS2) nanoparticles

Cobalt disulfide (CoS2) is a highly sophisticated metal chalcogenide that has garnered significant attention due to its distinctive properties such as its electrical, optical, catalytic, and magnetic capabilities and potential for use in a range of applications. In this work, pure CoS2 nanoparticles were synthesized using the economical and facile hydrothermal method. The X-Ray diffraction (XRD) method was used to characterize the synthesized sample, confirming that it has a cubic crystal structure with space group P a −3. The Debye-Scherrer’s formula was implemented to determine the average crystallite size of nanoparticles and found to be 24.24 nm. Through the use of Field Emission Scanning Electron Microscopy (FESEM), the morphology and effective grain size of the obtained sample was determined. FTIR spectrophotometry was used to examine the vibrational stretching of the various bonds in CoS2. UV-Vis spectroscopy is employed to measure the optical property of the sample. The optical bandgap calculated from the Tauc Plot is around 1.90 eV reflecting the presence of photovoltaic properties in the sample. The change in dielectric permittivity and loss have been observed for the sample in the frequency range of 100 Hz to 10KHz at different temperatures between 303K and 423K. The frequency-dependent electrical conductivity of CoS2 is also explained. The observations revealed the presence of unique electrical and structural properties in the synthesized sample.

Fullerene (C60)‐doped zinc‐aluminium layered double hydroxide/polyvinyl alcohol nanocomposites: Synthesis, characterization, and photodegradation of methylene blue from water solution

AbstractIntroductionLayered double hydroxides (LDHs) are widely studied anionite clays consisting of positively‐charged hydroxide nanosheets which is described by the general formula: [M(II)1−xM(III)x(OH)2][An−·mH2O], where M(II) and M(III) are the divalent (e.g., Mg2+, Zn2+, Ca2+, Co2+, Ni2+, etc.) and trivalent (e.g., Al3+, Fe3+, Cr3+, etc.) metal ions, An− and H2O is the interlamellar anion (e.g., Cl¯, Br¯, NO3¯, CO32¯, SO42¯, SeO42¯) for charge‐neutralization and hydrated state, respectively. They have been widely used in different industry sectors, in materials science and research. Polymer/LDH nanocomposites have gained significant attention in recent years.Carbon‐based nanomaterials, like fullerene, carbon nanotubes (CNT), graphene and graphene oxide have attracted significant attention. Fullerene molecules (C60, C70) are used as reinforcing material for polymers to improve their mechanical, thermal, optical, energy storage and charge transport properties.ObjectivesC60‐doped ZnAl‐layered double hydroxide/polyvinyl alcohol nanocomposites were successfully synthesized and their photocatalytic activity for photodegradation of methylene blue (MB) synthetic dye was quantitatively analyzed by ultraviolet (UV) spectroscopy. The effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied.MethodsFullerene‐doped ZnAl‐LDH/PVA nanocomposites were synthesized via urea hydrolysis and coprecipitation‐coformation method. First, 10 wt% PVA/water solution (40 mL) is added into the mixed solution containing 0.015 mol of Zn(NO3)2·6H2O and 0.005 mol of Al2(SO4)3·9H2O and titrated by 2 M of NaOH and 1 M of NaHCO3 mixed base solution to adjust pH 9. The obtained white slurry was shaken very hard and aged for 1 year. The obtained samples were marked by the mass percentage of C60 as 1% C60@LDH/PVA, 10% C60@LDH/PVA, 20% C60@LDH/PVA, and 60% C60@LDH/PVA.Results and DiscussionThe basal spacing of C60‐doped ZnAl‐LDH was estimated to be 9.217 Å which is wide enough from the general LDH (~7.0 Å). The crystallite size of nanoparticles is 9.217 nm and ~6 nm by Scherrer's equation and Williamson–Hall method from the XRD data, respectively. Rice‐shaped 2D morphology was formed with 100 nm–2 μm width and 500 nm–10 μm in length by SEM. The maximal photodegradation efficiency was found with 20% of C60 doping (PD% = 96.98) after 360 min, where the sorption efficiency with this compound is very high (R% = 85.55).ConclusionsIn the presented work, the effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied. For the identification of the photocatalytic activity of obtained C60/LDH nanocomposites, MB was used as a model pollutant and the efficiency of the Zn/Al LDH nanocomposite, with various quantities of fullerene, is also evaluated.

Luminescent Eu3+ doped SrF2 nanoparticles for fluorescent detection of fertilizers

Luminescent Eu3+-doped SrF2 nanoparticles were synthesized using microwave-assisted synthesis. Their surfaces were modified either by polyethylene glycol or mercaptopropionic acid to enhance their dispersibility in aqueous media and colloidal formation. X-ray diffraction analysis confirmed single-phase cubic structure in both types of hydrophilic-modified Sr0.9Eu0.1F2 luminescent powders. The average crystallite size of nanoparticles is found to be ∼13 nm. Scanning electron microscopy of the representative PEG2000-modified sample revealed that particles form agglomerates composed of densely packed nanoparticles. The microstructure at a local level was investigated by transmission electron microscopy showing the presence of sphere-like nanoparticles with an average particle size of 12.5 nm and 14 nm for PEG-modified and MPA-modified Sr0.9Eu0.1F2, respectively. Both PEG2000 and MPA-modified Sr0.9Eu0.1F2 water dispersions show strong red Eu3+ emission under 405 nm excitation that is quenched in the presence of the primary NP fertilizer, ammonium dihydrogen phosphate, NH4H2PO4. The limit of detection was calculated to be ∼19 mM for both hydrophilic-modified Sr0.9Eu0.1F2 luminescent nanoparticles.

Core shell heterojunction interface in green synthesized Sm3+ ions doped ZnO nano-particles to promote the charge separation for efficient photocatalytic applications

In this work, we report core-shell heterojunction of Sm3+ ions doped ZnO nanoparticles (NPs) by green synthesis technique and their photocatalytic activity for rapid degradation of methyl green dye molecules under UV light irradiation. High-resolution X-ray diffraction and high-resolution transmission electron microscope characterization techniques were employed to investigate structural and morphological studies. It is found that, the crystallite size of NPs is decreased with increasing Sm3+ ions concentration in NPs since Sm3+ ions are inhibiting the further growth of NPs. In addition, Sm3+: ZnO NPs catalyst shows irregular core shell heterojunction ensuing in the augmentation of a charge partition. Following that, the elemental compositional studies of Sm3+: ZnO NPs were estimated by energy dispersive spectroscopy. XPS imaging is also done in this work to get chemical mapping and the results suggested that the peaks are related to the Sm3+ ions in the ZnO lattice, which confirms the appropriate incorporation of Sm3+ into the ZnO. The optical energy band gap of NPs was estimated using diffuse reflectance spectroscopy. Excitation spectrum of Sm3+: ZnO NPs tinted the typical f-f transitions of Sm3+ ions. Photoluminescence emission shows the e− /h+ pair recombination rate reduced with increasing wt% of dopant Sm3+ ions in NPs. 10 wt% Sm3+: ZnO NPs showed the optimum photodegradation efficiency towards methyl green dye under the irradiation of UV light for 50 min. The dye degradation rate of Sm3+: ZnO NPs was 91% which is 26% higher than that of pristine ZnO NPs. Furthermore, the catalyst retains its original efficiency after fifth cycle.

Wet chemical synthesis and characterization of CuO nanoparticles and their application in pool boiling heat transfer

There are several ways to synthesis nanoparticles, including chemical, physical, and biological processes. In general, chemical approaches are thought to be the most effective for producing uniformly sized and stable nanoparticles. This study deals with the synthesis and characterization of copper oxide nanoparticles (CuO-NPs) that could be used in pool boiling heat transfer in the form of nanofluid. The wet chemical synthesis method was used in order to prepare copper oxide nanoparticles (CuO-NPs) using precursor copper nitrate trihydrate (Cu(NO3)2⋅3H2O) and citric acid in a molar ratio of 5:1 in ethylene glycol (C2H6O2) solvent. The nanoparticles were identified using their stability, crystal size, and particle size. FTIR, XRD, and UV–Visible Spectroscopy all provide evidence that CuO-NPs exist. The typical nanoparticle size, as determined by Zetasizer, was 72.87 nm. The Scherrer formula was used to ascertain the average crystallite size of nanoparticles, which was determined to be approximately 19.82 nm. Positive findings from the stability test on nanoparticles were obtained, and their zeta potential was about –32.51 mV. According to morphological analyses by SEM, the synthesized CuO-NPs were made up of evenly dispersed spheroid-shaped particles that were agglomerated. The amount of reducing agent and calcination temperatures has a significant impact on the nanoparticle's size. The results of the experiment show that the addition of nanoparticles has a significant impact on the value of critical heat flux (CHF).

Fabrication of magnesium oxide nanoparticles using Eucalyptus tereticornis seed extract and their characterisation

Abstract The green approach is a simple and efficient method for generating metal oxide nanoparticles. Magnesium oxide nanoparticles gained prominence due to their unique biodegradation, microbe growth inhibition, and non-toxicity properties. The seed extract of Eucalyptus tereticornis was used to make magnesium oxide nanoparticles in this research. Using X-ray diffraction data, the average crystallite size of nanoparticles is estimated to be about 10 nm. Face-centered cubic structured magnesium oxide nanoparticles have a spherical surface morphology, as seen in transmission electron microscopy and scanning electron microscopy images. Fourier transform infra-red spectra are used to identify functional groups involved in the stabilization and reduction of precursor salt. Magnesium oxide nanoparticles are employed for a variety of applications including temperature dehydrating agents, high-grade ceramic materials, optoelectronic fields, and bio-medical studies such as antibacterial and antimicrobial.

Synthesis, characterization, and the influence of energy of irradiation on optical properties of ZnO nanostructures

Zinc oxide nanoparticles (NPs) are synthesized by the sol–gel method for optoelectronics, photonic, and medical applications. The as-synthesized NPs are irradiated with lasers with wavelengths of 1064 nm and 532 nm in an attempt to improve the particles' structural and functional properties. The NPs are characterized by means of X-ray diffraction, scanning and transmission electron microscopy techniques, atomic force microscopy, and ultraviolet–visible spectroscopy. The structural analysis shows that the particles have a polycrystalline hexagonal structure of the space group (P63mc). The average crystallite size of nanoparticles varies in the range of 13–15 nm after and before irradiation by a laser beam. The morphological characterization revealed the formation of agglomerates of NPs in the range of 42–46 nm A shift is observed in the absorption spectra after irradiation with a laser beam. This shift is due to the effect of irradiation on the sample’s electronic structure. This effect is confirmed by a decrease in the bandgap energy. The optical parameters are also deduced and discussed. The irradiation of ZnO nanoparticles by laser beams of wavelength 1064 nm and 532 nm decreases the size of the crystallites which increases their antibacterial activity. The biological activity of the NPS and in improving the efficacy of antibiotics are tested and analyzed. Results emphasized the positive role of ZnO-NPs in the above-mentioned application.

Understanding the structure-property correlation of tin oxide nanoparticles synthesized through the sol-gel technique

The present study aims at exploring the structural, morphological, optical, defects and phase related aspects of the sol-gel synthesized highly pure tin oxide (SnO2) nanocrystallites as a function of sample annealing temperature by carrying out experiments using various spectroscopic and analytical techniques. The X-ray diffraction (XRD) and high resolution transmission electron microscopic (HRTEM) studies confirmed the nanocrystallinity of the samples as the average sizes of the crystallites were found in between 10 and 20 nm. Williamson – Hall (W − H) analysis was employed for estimating the lattice strain and exact crystallite size of nanoparticles (NPs). The monotonous decrease of lattice strain with sample annealing temperature is consistent with increase of crystallite size by increase in temperature. The NPs exhibited some specific anomalous behaviour, among which a prominent one is the increased lattice parameters and unit cell volumes with the decrease of crystallite sizes. The optical band gap was observed to increase when the nanocrystallites became smaller in size. The latter aspect is attributable to the onset of quantum confinement effect, as observed in a few other metal oxide NPs. The atomic vibrations were characterized through distinct absorbance bands appeared in Fourier-transform infrared (FT-IR) spectroscopy. The photo-induced luminescence properties were studied by Fluorescence (FL) spectroscopy in terms of defects and/or oxygen vacancies related transitions. Positron annihilation lifetime spectroscopy (PALS) was employed to study the vacancy type defects, which were abundant in the samples and played crucial roles in modulating their properties. The results suggest the feasibility of tailoring the properties of SnO2 NPs synthesized through sol-gel route-for technological applications. It also provides the physical insight into the structural build-up process when crystallites were formed with a finite number of atoms, and their distributions were governed by the site stabilization energy. Since the samples of smaller crystallite sizes have remarkably larger defect concentrations.

Cr3+ substitution influence on structural, magnetic and electrical properties of the Ni0.3Zn0.5Co0.2Fe2-xCrxO4 (0.00 ≤ x ≤ 0.20) nanosized spinel ferrites

• The sol-gel auto combustion method prepared the Cr 3+ substitution in Ni 0.3 Zn 0.5 Co 0.2 Fe 2-x Cr x O 4 (0.00 ≤ x ≤ 0.20) ferrite nanoparticles. • The measured lattice constant and crystallite size from XRD data show a single-phase cubic spinel. • FESEM images indicate the particles are of small size are confirmed. • There were two absorption peaks around 577.43 cm −1 and around 392.46 cm −1 in the FTIR spectra supporting their spinel structure, as is indicated by the XRD pattern. • The magnetic saturation decreased from 110.87 to 70.28 emu/g with the Cr 3+ ions substitution. • The BB interaction is prominent over the AB interaction, and the DC electricity measurement shows their highly resistive nature. The sol-gel auto combustion method was used for the preparation of the Cr 3+ substitution in Ni 0.3 Zn 0.5 Co 0.2 Fe 2-x Cr x O 4 (0.00 ≤ x ≤ 0.20) ferrite nanoparticles. The XRD data show a cubic spinel structure with a single phase of the samples. The crystallite size of nanoparticles was found to be in the range of 36.74–25.91 nm. Lattice parameter decreases with Cr 3+ concentration increases. SEM micrographs of the nanocrystalline ferrites show an increasing trend in average grain size. There were two absorption peaks around 577.43 cm −1 and around 392.46 cm −1 in the FTIR spectra supporting their spinel structure, as is indicated by the XRD pattern. The magnetic measurements show that the saturation magnetization and coercivity decreases as concentration increases.. The sample with x = 0.00 has a maximum saturation magnetization of 110.87 emu/g. Interlattice interactions are peculiar for tetrahedral and octahedral coordination, and dc electricity measurements reveal their highly resistant character.

Effect of fuel concentration on structural, vibrational, morphological properties and particle stability of NiO nanoparticles

In this present research, a simple cost-effective auto-combustion method has been adopted to prepare NiO nanoparticles with nickel nitrate and urea as raw materials. Urea has been taken as a fuel to perform combustion processes with different concentrations (50%, 75%, and 100%). The effects of urea concentration on structural, optical, morphological properties, and colloidal stability of NiO nanoparticles were analyzed through various techniques (XRD, FT-IR, SEM, and Zeta Potential analyzer). The single-phase cubic structure of NiO nanoparticles was examined through an XRD profile, and it confirms that the crystallite size of the nanoparticles is in the nanoscale range. The average crystallite size of NiO nanoparticles increases with an increase in fuel concentration (18.2 nm for 50%, 27.3 nm for 75,% and 38.4 nm for 100%). Among three different fuel ratios, 50% urea has been concluded as the optimum fuel ratio to prepare fewer particles. The functional groups present in all three samples were recorded by FT-IR spectra, which confirms the metallic Ni-O presence in all the samples. The role of fuel ratio on morphology was also examined by SEM micrographs, and morphological changes under three fuel ratios were also observed. The colloidal stability of NiO nanoparticles for all three samples was analyzed by a zeta potential analyzer, and it confirms that the stability of the samples is varied with fuel ratios. Using UV–vis spectra, the optical band gap of NiO nanoparticles was calculated. The optical band gap of NiO nanoparticles decreases as particle size increases.

Sintering temperature optimization for terbium doped strontium hexaferrite with improved microwave properties

Optimizing reaction parameters while undergoing synthesis process can help in customization of materials to be used in high frequency devices. However, optimization in terms of reaction parameters remains a challenge and not much success has been achieved so far even after years of sustained research efforts in this direction. We in this paper report our results on synthesization of M−type hexaferrite nanoparticles with composition Sr1-xTbx Fe12O19 (where × varies from 0 to 0.10 in steps of 0.02) using chemical co-precipitation method. Thorough investigations have been carried out to find out the variation in crystallite size of nanoparticles with change in terbium ion concentration from 2 % −10 %, using XRD results and TEM micrographs. Detailed analysis has also been carried out to study the impact of increase in sintering temperature on the dielectric properties for a frequency range of 1–6 GHz using Vector network Analyzer. While dielectric constant values were found to be in the range of 4–21, absorbance showed a variation of 5 % with change in sintering temperature. The average value of dielectric loss for pure strontium hexaferrite sample has been found to be 6.0 × 10−2 and vary between 5.1 × 10−2 and 1.38 × 10−1 for other compositions. According to the results, the sintering temperature of 1200 °C has been established as optimum for the sintering of the material. The material thus synthesized is suitable for millimeter wave antenna applications.

Facile Synthesis of Spherical Flake-shaped CuO Nanostructure and Its Characterization towards Solar Cell Application

The aim of this work is to synthesis CuO nanoparticles and investigates their eminent properties to identify their diverse application capability in the field of solar cells. In this work, CuO nanoparticles were synthesized by precipitation method using Copper (II) nitrate and Copper (II) chloride. Surface effects due to defects, structural properties related through lattice parameter, and crystallite sizes of nanoparticles have been identified from XRD. The crystal plane and reflection peak position was calculated using Bragg’s law. It showed that CuO nanoparticles have a monoclinic structure, and that the average crystallite size of CuO nanoparticles was 28.82 nm. n-type semiconductor behavior had a direct band of Eg = 1.465(2) eV, analyzed from optical studies by DRS. The band gap of the sample was determined from the reflectance spectra using Kubelka-Munk (K-M) function. Elements present were found through absorption peak of FTIR. The blue shifts observed in FTIR spectra in CuO nanoparticles were compared with that of bulk CuO, and absorption band agreed with XRD results. Morphological studies revealed the formation of spherical flake-shaped formation of CuO. It had a higher surface area and was well-suited to solar cell applications. HIGHLIGHTS The CuO nanoparticles were synthesized by precipitation method The average crystallite size of CuO nanoparticles obtained in the range of 28.82 nm Spherical flake-shaped nanostruture with higher surface area formed in this method Optical property of CuO (Eg = 1.465 eV) and good electron mobility make it a suitable solar cell absorber material GRAPHICAL ABSTRACT

Investigation on anneal-tuned properties of ZnFe2O4 nanoparticles for use in humidity sensors.

The effect of different annealing temperatures on structural, optical and magnetic properties of ZnFe2O4 nanoparticles prepared using the coprecipitation technique has been investigated. With the increase in annealing temperature, crystallinity and average crystallite size of nanoparticles increased. The average crystallite size was found to be 5.55 nm, 6.62 nm and 32.9 nm for the samples annealed at 300 °C, 500 °C and 700 °C, respectively. The X-ray diffraction and Fourier-transform infrared spectroscopy revealed the formation of a cubic spinel structure. The optical direct and indirect bandgap energy decreased with an increase in annealing temperature. The saturation magnetization increased from 16.38 emu/g to 25.91 emu/g. The M–H curves depicted the magnetic phase transition from superparamagnetic to ferrimagnetic. The electrical properties were investigated using an impedance analyzer in the frequency range of 300 Hz to 1 MHz. The conduction properties showed enhancement with increased annealing. The humidity sensing properties were investigated in the range of 15–90% RH and revealed a strong dependence of adsorption capacity on the annealing temperature. Electrical conductivity improved with increased humidity. Excellent humidity sensitivity was observed for ferrites annealed at 700 °C attributed to increased crystallinity and reduced lattice strain making them a potential candidate for use in humidity sensors.

Antimicrobial Effect of Silver Nanoparticles Synthesized with Bougainvillea Glabra Extract on Staphylococcus Aureus and Escherichia Coli

Considering the antimicrobial properties of silver and its enhanced level at nanoscale scale, it can be used to combat the various pathogens and microbial agents. The aim of this study was to investigate the antimicrobial effect of silver nanoparticles synthesized with Bougainvillea Glabra extract on standard strains of Staphylococcus aureus and Escherichia coli. In this study, silver nanoparticles were biosynthesized using the aquatic Bougainvillea Glabra extract under optimal conditions. The synthesis of silver nanoparticles was confirmed using UltraViolet-Visible (UV-Vis) spectroscopy and X-Ray Diffraction (XRD). Based on the X-ray diffraction pattern, the silver nanoparticles crystallite size was 21 nanometers. Transmission Electron Microscopes (TEMs) and Scanning Electron Microscopes (SEM) showed the synthesis of silver nanoparticles of about 23 nm in size and spherical morphology. Revitalizing and stabilizing agent groups were identified using Fourier-Transform InfraRed (FT-IR) spectroscopy. The mean diameter of the inhibition zone and the Minimum Inhibitory Concentration (MIC) were 27.6 mm and 3.12μg/mL for S. aureus and 19.3mm and 12.5μg/mL for E. coli, respectively. Biological synthesis using Bougainvillea Glabra aquatic extract is a very inexpensive and cost-effective method. The ability of Bougainvillea Glabra to synthesize silver nanoparticles makes it possible to use this plant as a useful biological source for the synthesis of silver nanoparticles with suitable and practical sizes for medical and microbicide applications.

Aluminum Substitution in Ni-Co Based Spinel Ferrite Nanoparticles by Sol–Gel Auto-Combustion Method

In this research work, aluminum substituted Ni-Co ferrite nanoparticles have been produced by a simple and cost-effective method, i.e., sol–gel auto-combustion. Synthesized nanoparticles were annealed in a muffle furnace at 600°C for 3 h before characterization. The x-ray diffraction patterns revealed that the ferrite nanoparticles grew preferentially along the (311) plane and exhibit face centered cubic structure. The crystallite size of nanoparticles (14 to 17 nm) was estimated by Scherrer’s relation. The effect of aluminum substitution on structural parameters of ferrite nanoparticles, such as lattice constant and stacking faults, have been studied. Structural analysis revealed that the lattice constant of the nanoparticles decreases as a function of aluminum content. The Fourier transform infrared spectroscopy confirmed the spinal ferrite crystal structure of synthesized aluminum substituted Ni-Co ferrite nanoparticles. The surface morphology observed through scanning electron microscopy depicts the growth and distribution of nanograins with uniform size with in the samples. Dielectric properties investigated through impedance analyzer spectroscopy revealed that aluminum substituted Ni-Co ferrite nanoparticles demonstrated the high conductivity along with potential dielectric properties. These aluminum substituted Ni-Co ferrite nanoparticles would have possible applications in high storage memory and microwave devices.

Impact of Lanthanum-Doping on the Physical and Electrical Properties of Cobalt Ferrites

Cobalt ferrites have attracted extraordinary attention due to their high coercivity, chemical stability, and mechanical hardness. Lanthanum doped-cobalt ferrites having chemical formula CoLaxFe2-xO4 with composition x = (0.00, 0.015, 0.045, 0.060) were synthesized by chemical co-precipitation method. The prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and current-voltage (I-V) technique. The structure of the crystal was analyzed by X-ray diffraction. The crystallite size of nanoparticles was examined in the range of 21–25 nm, and a fluctuating trend was found with the inclusion of La3+ cations. The X-ray diffraction patterns verify the contraction of lattice constant and unit cell volume with the substitution of La3+ cations except for the concentration of x = 0.060. Lattice constant was in the range of 8.34 A–8.41 A while unit volume cell was in the range of 580 A3–596 A3. The resistivity of all samples was calculated by the application of two probes I-V technique. The maximum resistivity of the order of 81.129 × 105 Ω cm was found for the concentration of x = 0.060 at 723 K which makes it useful for high-frequency gimmicks applications. The resistivity and drift mobility were found inversely related to each other. The inverse relation low-frequency absorption band and high-frequency absorption bands were analyzed by Fourier-transform infrared spectroscopy technique.

A new approach to optimize the synthesis parameters of TiO2 microsphere and development of photocatalytic performance

In this study, Titanium (IV) Oxide (TiO2) microspheres were synthesized by hydrothermal method, and Cerium Oxide (CeO2) nanoparticles in the ratios of 0.1, 0.25, 0.5 and 1 mol% were loaded onto these microparticles by surfactant-assisted (Pluronic 123) sol–gel method. The crystal properties and surface morphology of the synthesized TiO2–CeO2 hybrid photocatalysts were investigated by X-ray diffraction method (XRD) and field emission scanning electron microscope (FESEM). Bond structures and surface areas were examined by Fourier-transform infrared spectroscopy (FTIR), Raman and Brunauer–Emmett–Teller (BET) analysis, respectively. XRD patterns with (101) and (200) main planes show that nanoparticles have anatase TiO2 phase. Also, A1g, B1g and Eg Raman modes confirms anatase TiO2 phase. In addition, with CeO2 doping, while the average crystallite size of nanoparticles decreased, their surface area increased. The photocatalytic activity of the prepared photocatalysts were investigated by degradation of the methylene blue (MB) under UV light (λ = 365 nm). The results showed that the surface area and crystal structure of hybrid structure and interface interaction between TiO2 and CeO2 have a significant effect on photocatalytic performance. The 0.1% CeO2–TiO2 photocatalyst degraded almost 95% of the MB solution in about 60 min, while for TiO2 microspheres this value is around 80%. Also, we observed that 0.1% CeO2–TiO2 led to about 1.4 times higher reaction rate in comparison to TiO2. Results showed that the hybrid photocatalysts has a higher performance than bare TiO2 microspheres.

Synthesis and Characterization of the Properties of Ceria Nanoparticles with Tunable Particle Size for the Decomposition of Chlorinated Pesticides

Ceria nanoparticles are well known for their catalytic properties, which are commonly used in the automotive industry and other chemical branches. In this contribution, ceria nanoparticles were prepared by a simple precipitation reaction of cerium (IV) sulfate and ammonia. Such nanoparticles were very fine, with an approximate crystallite size of 2 nm. Crystallite sizes of these nanoparticles were adjusted by controlled heating, showing different catalytic properties. After thermal treatment, the surface area and crystallite size of nanoparticles were also compared by means of XRD and a sorption analyzer utilizing Brunauer–Emmet–Teller (BET). Morphology was studied by SEM, high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED). Thin layers of ceria nanoparticles on silica glass and alumina ceramic underlays were also prepared and studied by SEM and EDS to demonstrate the possibility of ceria immobilization using thermal treatment of raw nanoparticles. The catalytic activity of the nanoparticles was tested on a 2,4,6-trichlorophenol aqueous solution and compared by UV–VIS spectroscopy.

Salvadora persica root extract-mediated fabrication of ZnO nanoparticles and characterization

Biocompatibility of nanoparticles (NPs) uses the plant extract as a reducing agent for synthesis and are cost-effective. The existing research focused on fabrication of zinc oxide (ZnO) NPs using Salvadora persica L. root extract as a reducing agent and noticed that varying the extraction solvent varies the morphology of ZnO NPs. The existence of alkaloids, acids, volatiles, and essential oils in root extract helps in ZnO NPs fabrications from its precursor zinc acetate dihydrate. The calcined resultant nanopowders are then characterized by UV-Vis spectroscopy, FTIR, XRD, and SEM. SEM analysis showed the ZnO NPs have hexagonal wurtzite structure in aqueous dispersion medium while nanorods formed in methanol. The synthesized ZnO NPs crystallite size found 24–25 nm. Besides the function of oral hygiene and various properties of Miswak, it can be employed for the ZnO NPs synthesis. These ZnO NPs with different morphology can be used in medical applications, biosensors, photochemical, and electrical applications.

Magnetic nanocellulose: A potential material for removal of dye from water

In this study, cellulose nanofibers are used as a template to synthesise magnetic nanoparticles with a uniform size distribution. Magnetic nanoparticles are grafted on the surface of nanofibers via in situ hydrolysis of metal precursors at room temperature. Effects of different concentrations of nanofibers on the morphology, the crystallite size of magnetic nanoparticles, and the thermal and magnetic properties of the membrane produced from the cellulose nanofibers decorated with magnetic nanoparticles are examined. The sizes of magnetic nanoparticles produced in this study are below 20 nm, and the crystallite size of the nanoparticles is in the range of 96−130 Å. The flexible magnetic membranes containing a high concentration of magnetic nanoparticles (83−60 wt%) showed superparamagnetic behaviour with very high magnetic properties (67.4–38.5 emu g−1). The magnetic membrane was then used as an environmentally friendly, low-cost catalyst in a sulphate radical-based advanced oxidation process. The membranes successfully activated peroxymonosulphate (PMS) to remove Rhodamine B (RhB), a common hydrophilic organic dye applied in industry. 94.9 % of the Rhodamine B was degraded in 300 min at room temperature, indicating that the magnetic nanocellulose membrane is highly effective for catalyzing PMS to remove RhB.