Crystallite Structure Research Articles

Crystallite structure and magnetic characteristics of iron oxide nanoparticles biomineralized by Shewanella spp. With different surface charge potentials

Crystallite structure and magnetic characteristics of iron oxide nanoparticles biomineralized by Shewanella spp. With different surface charge potentials

The development of multifunctional biochar with NiFe2O4 for the adsorption of Cd (II) from water systems: The kinetics, thermodynamics, and regeneration.

High concentrations of Cd (II) in wastewater have been reported several times which attracted top research attention to mitigate the pollution impacts of the contaminant. Therefore, this study aimed to develop a Zn-doped NiFe2O4- pinecone biochar composite (ZNiF@PB) for the adsorption of Cd (II) from wastewater. FTIR confirmed immobilization of PB on the surface of ZNiF by the presence of C = O at 1638cm-1, COOH at 1385cm-1, C-O at 1009cm-1 and Fe-O at 756cm-1. Similarly, XRD determined the crystallite structure of the adsorbents where the ZNiF crystallite size of 43nm was obtained while the particle size of ZNiF@PB was found to be 38nm. These XRD results agreed with those values obtained from TEM images showing ZNiF and ZNiF@PB had a spherical shape with similar particle sizes. On the other hand, the surface areas of ZNiF, PB, and ZNiF@PB were found to be 78.4m2/g, 125m2/g, and 104m2/g, respectively. These high surface areas have a huge potential to enhance Cd removal. With these adsorbents, the maximum Cd (II) adsorption of 96% was recorded at the optimum experimental condition of adsorbent dosage 0.5g/50mL, solution pH 6, initial Cd (II) concentration 100mg/L, and contact time 120min. Practical adsorption kinetics data were well described by the pseudo-second order model whereas the adsorption isotherm was a perfect fit to the Langmuir isothermal model implying the adsorption process to be a monolayer with mainly a chemically bonded mechanism. In conclusion, this adsorbent is efficient for the adsorption of Cd (II) from wastewater and has also a huge potential to be applied for industrial-scale water purification.

Degradation of air pollutants from waste burning using photocatalyst TiO2 with Co(NO3)2 doped under ultraviolet irradiation

Air pollutants, such as carbon dioxide (CO2), hydrogen cyanide (HCN), and methane (CH4), can harm the respiratory organs of humans and cause several diseases. This study successfully utilized a photocatalyst from TiO2 with Co(NO3)2 doped to degrade these air pollutants from waste burning. The photocatalyst layer was produced by dissolving TiO2 and Co(NO3)2 in distilled water, and then the solution was coated on a mica surface using a spray coating method. The coated mica was then dried in an oven. The crystallite structure of TiO2/Co(NO3)2 was analyzed by X-ray diffraction. The obtained crystallite size was (15.38 ± 0.03) nm with lattice parameters a and c were (3.8 ± 0.3) Å and (9.3 ± 0.3) Å, respectively, which shows that it is an anatase phase. The band gap energy was measured by diffuse reflectance UV-visible spectroscopy and analyzed by Tauc's plot method. The measured band gap energy of the photocatalyst was 2.81 eV, which can be easily activated by ultraviolet (UV) light. The photocatalyst sheets successfully degraded air pollutants from waste burning, including 53.139% CO2 for 4 hours, 100% HCN for 10 minutes, and 72.381% CH4 for 40 minutes. Therefore, the fabricated photocatalyst in this study can potentially be an alternative to degrading air pollutants, especially CO2, HCN, and CH4.

Growth mechanism of Pb0.9Cd0.1Te: Pb thin films prepared by PVD technique

Abstract The complex surface morphology, defect subsystem and an ab initio model study of Pb1-xCdxTe thin films deposited on mica-muscovite substrates by PVD technology are presented in this paper. The thickness, growth mechanisms and uniformity of condensates dependence on deposition regimes were studied by scanning electron microscopy and energy-dispersive x-ray spectroscopy. The deposited films have a granular structure and sizes of crystallites depend on thickness and difference between substrate and condensate crystallographic parameters. The dominance of film growth by the Vollmer-Weber mechanism is demonstrate. Studies of film growth mechanisms allowed us to predict that the formation of grains and the dynamics of their size changes during film growth are caused by complex defects that are associated with Cd atoms in nodes and vacancies of chalcogens.

Electrical Properties of Micro-Nano Hierarchically Controlled Tin Dioxide Gas Sensors

Metal oxide semiconductor gas sensors, particularly those utilizing tin dioxide, are indispensable across various sectors, including medical diagnostics. The medical industry demands high sensitivity and selectivity to detect low gas concentrations. In our previous proposal, we integrated pulse-driven techniques with a micro gas sensor to achieve this goal. Additionally, nanostructure control, involving nanoparticles, nanoclusters, and nano/mesopores, is crucial for attaining these properties. Typically, this type of gas sensor exhibits high resistance at elevated temperatures. However, maintaining low electrical resistance at temperatures between 200°C to 400°C poses a challenge due to the associated low cost of electronic circuits. At lower temperatures, sensor resistance in the air often surpasses measurement limits. In the microsensors' sensing film, it is believed that as the sizes of secondary and tertiary particles draw closer to the electrode gap due to particle agglomeration, the contact area of these larger particles with the electrodes decreases, resulting in higher electrical resistance. Although metal oxide semiconductor gas sensors have primarily focused on the nano effect of particles, the combined nano and micro effects arising from micro-size agglomeration have not been extensively explored. Therefore, our research aims to investigate the micro-size effect of tin dioxide on micro gas sensors and evaluate its impact on electrical properties such as electrical resistance and sensor response.To synthesize tin dioxide, we utilized the reverse homogeneous precipitation method using SnCl4 and NH4HCO3, followed by the elimination of Cl ions through centrifugation. The resulting sol was dried, ground, and calcined in wet-O2 at 600°C for 3 hours. The obtained powder was mixed with water and separated into fine and coarse agglomeration using sedimentation and centrifugation method. Material characterization included X-ray diffraction (XRD) for analyzing crystallite structure, scanning electron microscopy (SEM) for observing microstructure, Brunauer-Emmett-Teller and Barrett-Joyner-Halenda (BET-BJH) analysis to assess pore structure from nitrogen adsorption-desorption isotherm, and particle size distribution (PSD) analysis. Micro gas sensor devices were fabricated for sensor measurements, with a focus on assessing the electrical resistance of SnO2 micro gas sensors in air and their response to various gases.XRD analysis revealed a rutile structure pattern in all tin dioxide samples, with no distinct average crystallite sizes (around 18 nm). SEM results showed fine SnO2 agglomerates predominantly less than 1 μm, while coarse SnO2 agglomerates were less than 5 μm, consistent with PSD analysis showing narrower distributions for fine and coarse SnO2, with mean particle sizes of 0.2 μm and 2 μm, respectively. BET results indicated that fine SnO2 had a specific surface area of 22 m2g-1, while coarse SnO2 had 19 m2g-1. BJH results showed that fine SnO2 had a specific pore volume of 0.17 cm3g-1, whereas coarse SnO2 had 0.09 cm3g-1. These pore properties suggest that fine SnO2 has a larger specific surface area and pore volume than coarse SnO2. Measurements of electrical resistance in air were conducted across temperatures ranging from 350°C to 200°C. Sensors containing fine SnO2 particles exhibited lower resistance compared to conventional tin dioxide sensors, indicating a potential influence of finer agglomerates on electrical properties. The sensor's response to various gases will be shown during the presentation.

Exploring the multi-scale evolution mechanism of the ultra-high-temperature mechanical behaviour of carbon/carbon composites

The microstructure and mechanical properties of Carbon/Carbon (C/C) composites were investigated after ultra-high-temperature heat treatment (HTT) in the range of 30 – 2950 °C. The evolutionary mechanisms of the mechanical behaviour were explained at three scales: graphene sheets, carbon fibre (CF) monofilaments and the C/C composites. The results displayed that the tensile strength of CF monofilaments decreases monotonically as the HTT increases, while C/C composites present a tendency to decrease and then increase, demonstrating that CF/matrix interfacial properties play a decisive role in the tensile properties. Obvious microstructure change of C/C composites after HTT at 2700 °C was observed, meanwhile the high temperature tensile strength (measured at 2000 °C and 2500 °C) for the composites treated at temperature beyond 2600 °C was higher than that of room temperature. The high-temperature mechanical properties of C/C composites were regulated by the competing mechanisms of the graphite crystallite structure and the skin-core structure of CF monofilament, the CF/matrix interfacial strength and the porosity of C/C composites.

Low thickness effect on the properties of Mn-doped ZnO thin films synthesized by sol-gel spin coating technique

In this study, 7% manganese-doped zinc oxide (MZO) thin films with varying low thicknesses were synthesized using the spin coating method. The structural, optical, and morphological properties of MZO films with different film thickness, were systematically investigated. The crystallite structure, superficial morphology, and optical characteristics were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV-Vis). Structural analysis confirmed that all films exhibit a hexagonal wurtzite phase with a pronounced peak along the c-axis, and slight variation in low thickness significantly affected the structural parameters. The surface morphology demonstrated good uniformity, characterized by rounded grain shapes in the plane, while surface roughness was found to be increased with increasing film thickness. Optical analysis revealed that as the number of coatings increased, both transmittance and band gap energy decreased, accompanied by a redshift in the absorption edge across all samples. This behavior is attributed to light scattering, as well as an increase in the refractive index and dielectric function with visible light energy, influenced by the number of layers and corresponding crystallite size.

Exploration of Pristine ZnO and Cobalt Doped ZnO for the Solar Photocatalytic Degradation of Methylene Blue Dye

The ZnO and Co-doped ZnO were prepared by eco-friendly and modest route, including thermal disintegration of zinc oxalate (ZnOx) and cobalt-zinc oxalate (CoZnOx) powders, respectively, from a mechano-chemical method. The process of conversion of metal/s oxalate dihydrate to the pristine ZnO and cobalt-doped ZnO was studied with TG-DTG and FTIR spectroscopy. ZnO and Co-doped ZnO crystallites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), UV–visible and photoluminescence (PL) spectroscopies. Hexagonal Wurtzite crystallite structures of the aforementioned materials were illustrated from XRD data. The surface morphological investigation was done with SEM. EDX study confirms the elemental purity of materials. Chemical bonding information was obtained from FTIR spectra. Optical properties were studied from UV-visible and photoluminescence spectroscopy. Exploration of pristine ZnO and cobalt-doped ZnO for the solar photocatalytic degradation (PCD) of methylene blue dye has been done in a batch photoreactor. The various related parameters such as photocatalyst amount, initial concentration of dye and pH were also examined for maximum degradation efficiency for mentioned dye.

Hydrothermal synthesis and optical luminescence center attribution in samarium-doped zirconia nanocrystals

Sm[Formula: see text] -doped ZrO2 (SDZ) nanocrystals were prepared via a hydrothermal route without subsequent calcination. These samples underwent a series of characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, and photoluminescence (PL) spectral. The results showed pure cubic ZrO2 nanocrystals, with a crystallite size of 8.4 nm, were achieved by doping 8 mol% Sm[Formula: see text]. It was observed that the concentration of Sm[Formula: see text] had a significant impact on the crystallite structure of the samples, which exhibited an array of spherical shape and irregular aggregates. The inclusion of PL emission bands, spanning from the ultraviolet to blue-green range, highlighted three distinct bands. These were analyzed using Gaussian fittings and were attributed to three different types of defects, referred to as the F, F1, and F2 centers, respectively.

Carboxymethyl cellulose assisted morphology controlled synthesis of Mn3O4 nanostructures for adsorptive removal of malachite green from water

The physicochemical properties of manganese oxides and their different applications mainly depend upon their crystallite size, morphology, phase structure, and surface properties, which are again dependent on the preparation methods. So, a simple, cost-effective, and versatile synthesis method for such materials is highly desirable. Intending to accomplish this, herein we report the synthesis of Mn3O4 nanostructures by alkaline hydrolysis of the corresponding metal ions in an aqueous medium. The addition of a biodegradable polymer, sodium salt of carboxymethyl cellulose (Na-CMC) assisted the development of specific morphology, which is tunable by varying the concentration of the biopolymer. The spectroscopic, microscopic, and diffractometric analyses of the synthesized Mn3O4 nanostructures confirm that this particular simple technique is very effective in controlling the morphology of the formed nanostructures. These Mn3O4 nanostructures exhibit excellent adsorption capacity in the removal of malachite green (MG) from its aqueous solution under ambient conditions. The adsorption process is exothermic following pseudo-second-order kinetics with a maximum dye adsorption capacity of 489.68 mg g−1 according to the Sips isotherm model. The Mn3O4 nanostructures can be reused for up to five cycles of dye adsorption without significant loss of their adsorption performance.

Supermolecule-Opitimized Defect Engineering of Rich Nitrogen-Doped Porous Carbons for Advanced Zinc-Ion Hybrid Capacitors.

Pitch-based porous carbons with adjustable surface chemical property and controllable pore structure are regarded as promising cathode materials for aqueous zinc-ion hybrid capacitors (ZIHCs), while its disordered carbon matrix and microstructure as well as insufficient surface defects often result in low Zn2+-storage capacity and poor rate capability of ZIHCs. Herein, a synergetic strategy of self-assembled supermolecule and enriched defective carbon engineering was developed to achieve ultrahigh edge-nitrogen doping for ZIHCs. The crystallite defects and surface structure of porous carbon could be effectively achieved through grafting electronegative oxygen-containing small molecules and high-level nitrogen-containing functional groups between modified polycyclic aromatic hydrocarbon and supermolecule framework. The optimized three-dimensional carbon structure delivered high capacity of 218 mAh g-1 at 0.2 A g-1, fast charge/discharge capability, enhanced energy density (165.4 Wh kg-1) and superior cycling stability (95 % retention after 10000 cycles as cathode of ZIHCs). This provided new insight into the controllable synthesis of carbon cathodes for ZIHCs and expects to prepare functional porous carbon by supermolecules and special precursors.

Enhanced ammonia gas sensing performance at room temperature of binder-free NiO, Cu and Co-doped NiO thin films synthesized via the SILAR method

We have comprehensively analyzed the influence of Cu and Co-doping on the structural, compositional, optical, and ammonia sensing characteristics of NiO thin films. The X-ray diffraction analysis revealed that pure NiO, Cu, and Co-doped NiO thin films possess a cubic structure. Remarkably, the Co-dopant caused a transformation in the crystallite size and surface structure of NiO. This alteration ultimately enhanced the sensing capabilities of Co-doped NiO thin films. The presence of Co decreased the amount of energy needed to activate Co-doped NiO, resulting in enhanced sensing capabilities of the doped samples for detecting 50 parts per million of ammonia with a response time of 20 s and recovery time of 16 s and having a percentage response of 76.25 %. The enhanced sensor responsiveness and selectivity of the Co-doped NiO sensor towards ammonia can be attributed to its increased surface area, smaller crystallite sizes, and superior surface properties. The remarkable results of Co-doped NiO thin films exhibited show a potential for use in the production of highly efficient ammonia gas-detecting devices.

Moisture dependence of responses in physical–chemical property and CH4 ad-/desorption capability of coals to microwave radiation

For purpose of understanding feasibility of coalbed methane (CBM) production in practical water (H2O)-containing reservoirs by using microwave radiation, the dielectric property highly associated with microwave-absorbing and resultant temperature-rising capabilities of coals were addressed primarily; afterward, the temperature-rising rule of coals and its dependence on moisture were examined; finally, the impacts of moisture on changes about main physical–chemical property and resultant CH4 ad-/desorption performance of coals were investigated under microwave field. Results indicated that the coals display microwave-absorbing potential to raise temperature. The moisture initially increases the temperature-rising rate owing to its strong microwave-absorbing capability while decreases the final bulk temperature because of its endothermal evaporation. The resultant rising temperature decomposes and transforms minerals. Moreover, the temperature rise upgrades crystallite structure of the dried coals. As for the wetted coals, the rapid temperature rise disorders crystallite structure of the Sihe and Yima coals due to potential steam explosion. Furthermore, the radiation decreases the aromaticity and the total surface oxygenic groups of the dried coals; the moisture whittles down these decreasing trends. In general, the micro- and mesopore surface area and volume of the coals drops after radiation. The microwave radiation smooths pore surface of the wetted coals while roughens that of the dried coals. The complexity of the coal pore structure almost reduces after radiation. Besides, the microwave radiation significantly reduces the CH4 adsorption capability of the dried coals by 6.74–36.69 %; the moisture further reduces the CH4 adsorption capability by 20.48–43.03 %. Ultimately, the microwave radiation almost enhances the ad-/desorption hysteresis of CH4 on the dried coals while weakens that of the wetted coals. Such alterations depend on the responses of pore abundance and pore surface roughness to microwave. These findings confirm that microwave radiation is a promising option to produce CBM, particularly for H2O-bearing CBM reservoirs.

Investigating the synergistic effect of Nd3+ and Ni2+ in CuO nanocrystals on their structural, optical, and magnetic properties for photovoltaic and photocatalytic implementations

The wet chemical precipitation technique was used to synthesize CuO, Nd:CuO and Ni-Nd:CuO nanoparticles efficiently. The produced substance was tested using X-ray diffraction (XRD) for confirming the crystallite structure, and scanning electron microscopy (SEM) was used to examine the morphological properties of the produced materials. Crystal defects and optical properties of the synthesized samples were analyzed through luminescence (PL) investigations and UV–Vis spectroscopy. EIS spectrum was utilized to study the electrochemical behavior of the prepared material. Vibrating Sample Magnetometer (VSM) was employed to examine the magnetic properties influencing from the doping of Ni2+ and Nd3+ ions into CuO, attributed to their substantial magnetic moment and ferromagnetic traits. Photovoltaic efficiency of the prepared material was studied by J-V characteristics and photon-to-electron converting efficacy (IPCE) studies. Photocatalytic properties were studied by degrading MB and RhB dyes. The enhancement in the photocatalytic performance of the Ni-Nd:CuO was a result of suppression of photogenerated electron-hole pair recombination and accelerated separation and migration of photogenerated charges.

Cobalt-doped ZnO nanoparticles and PLD-deposited thin film forms: structure, optical properties and nature of magnetic anisotropy.

Cobalt-doped zinc oxide nanoparticles (NPs) were synthesized using a modified sol-gel method. Thereafter, the obtained powder was deposited on a Suprasil glass substrate by employing a pulsed laser deposition (PLD) technique. X-ray diffraction analysis with Rietveld refinement confirmed a hexagonal wurtzite ZnO phase belonging to the P63 mc space group for both samples in the NP and thin film forms. In particular, the thin film exhibited an intensive (002) XRD peak, indicating that it had a preferred c-axis orientation owing to the self-texturing mechanism. No segregated secondary phases were detected. The crystallite structure, morphology, and size were investigated using high-resolution transmission electron microscopy (HRTEM). To study the crystalline quality, structural disorder, and defects in the host lattice, we employed Raman spectroscopy. UV-vis-NIR spectroscopy was performed to confirm the nature of the Co-doped ZnO NP powder and the film. The chemical states of oxygen and zinc in the thin film sample were also investigated via X-ray photoelectron spectroscopy (XPS). The M-T curve could be successfully fitted using both the three-dimensional (3D) spin-wave model and Curie-Weiss law, confirming the mixed state existence of weak ferromagnetic (FM) and paramagnetic (PM) phases. Magnetic interaction was quantitatively studied and explained by polaronic percolation of bound magnetic polarons (BMPs). Analysis of magnetic symmetry of the topological antiferromagnetic as-deposited thin film using torque measurements was performed. Based on a phenomenological model, it was revealed that the structure gives rise to uniaxial magneto-crystalline anisotropy (UMA) with the magnetic easy axis parallel to the c-axis.

Au–decorated TiO2 nanoparticle photoanode: synthesis, structural, optical properties and photoelectrochemical water splitting performance

This study presents a novel approach to synthesizing Au-decorated TiO2 (Au/TiO2) nanoparticles (NP) using a spin-coating method, showcasing significant advancements in photoanode development. The resulting Au/TiO2 NPs exhibit well-defined crystallite structures comprising Au and TiO2 phases, featuring Au NP sizes ranging from 2.61 nm to 6.10 nm. Notably, the energy bandgap of these Au-decorated TiO2 NPs demonstrates a discernible redshift of 3.22–3.02 eV across various Au concentrations (1%–20%). Photoluminescence spectra reveal three distinct emission peaks at room temperature in the 400–550 nm wavelength range. The water-splitting activity of the Au/TiO2 NPs is investigated through the photoelectrochemical cell (PEC) employing an electrolyte solution with 1.0 M KH2PO4/K2HPO4 buffer. The results demonstrate a substantial photocurrent density of 0.23 mA.cm–2 at a potential of 1.6 V (versus RHE) and a photoconversion efficiency of 0.1% at 0.52 V (vs. RHE), respectively. This pioneering study underscores the potential of Au/TiO2 NP photoanodes as key components in advancing sustainable energy technologies, particularly in the realm of efficient PEC water-splitting applications.

Novel Damsissa carbon quantum dots (DCQDs) to improve the protection efficiency of permanganate phosphate conversion coats (PPC) on steel

Carbon quantum dots (CQDs) are spherical zero dimensional nanoparticles, generally below 10 nm in size, which received increasing attention in diverse application fields owing to their important characteristics and advantages as good water solubility, potential of environmental protection and preparation from abundant and sustainable raw materials. In this work, Damsissa carbon quantum dots (DCQDs) were generated via hydrothermal reaction microwaves irradiation. The DCQDs material was characterized by FTIR, TEM, EDX, XRD, and XPS to confirm the morphological and functionality aspects as well as particle size distribution, elemental composition, crystallite structure, and elemental identification in terms of chemical state. The FTIR analysis referred to associated assignments of C-H, C=O, C=C, C-N, besides other groups. The TEM study confirmed a ranged homogenous particle distribution at 3-6 nm. The EDX and XPS results verified carbon, nitrogen and oxygen as the main elements in DCQDs. The protection efficiency performance of permanganate phosphate conversion coat (PPC) was investigated and monitored by using different concentrations of DCQDs in the coating bath utilizing the potentiodynamic polarization technique, besides electrochemical impedance spectroscopy. The results referred to 97.4% maximum protection efficiency for the coat in presence of 400 mg/L DCQDs. The impedance results showed that as the concentration of DCQDs increase, the capacity of the double layer (Cdl) decreases due to the adsorption ofDamsissa carbon dots on the steel surface. However, the potentiodynamic polarization results indicated that the presence of DCQDs in HCl solution could lead to the polarization of the cathodic and anodic curves to denote that these retard the cathodic and anodic reactions at the steel surface inhibiting the corrosion process. The coats synthesized in absence and in presence of diverse amounts of DCQDs were examined by the TEM, EDX, XPS, and XRD studies to elucidate the role of DCQDs in the improvement of the corrosion protection of the coat. The results indicated that the DCQDs molecules ofDamsissa were adsorbed at the steel surface to efficiently retard the dissolution of iron and decrease the Fe2+ ions concentration in the coating solution causing higher nucleation rate over the crystal growth and thus leading to the formation of a uniform protective film.

Evolution of Morphology, Particle Size and Oxidation Resistance of Recycled Ti-6Al-4V Powders Prepared by Planetary Ball Milling

AbstractPlanetary ball milling is a high-energy ball milling technique that is widely used for the synthesis of alloy and composite powders with micrometer or nanometer particle sizes. The effect of process control agent (PCA) content (wt%) and milling time on the morphology, particle size and distribution, crystallite structure, apparent density and oxidation resistance of recycled T-6Al-4V alloy powders from lathe chips is investigated in this study. To investigate the effect of the PCA on the properties of the Ti-6Al-4V alloy particles, methanol is used as the PCA in various amounts of 0.5, 1 and 2 wt%. The milling is carried out using 20:1 of ball-to-powder ratio (BPR) and 400 rpm of milling speed. A morphological change from scrap form to flake-like shape, from flake-like morphology to irregular and semispherical shape and finally from semispherical form to spherical morphology is observed with increase in milling time for all PCA ratios. The results showed that the average particle sizes (D50) are 20, 18.1 and 21.8 μm after milling of 360 min with 0.5 wt%, 1 wt% and 2 wt% PCA, respectively. Results show that the most suitable recycled Ti-6Al-4V powders for powder-based manufacturing techniques are produced between 180 and 360 min of milling with 2 wt% PCA.

Morphological Characterization of Sb-Doped SnO2 Thin Films Developed by Spray Pyrolysis

In the present work, we have successfully deposited Sb antimony doped tin dioxide (SnO2) thin films with different concentrations (0 at%, 1 at%, 3 at% and 5 at%) from a stannous (II) chloride dihydrate solution (SnCl2.2H2O), by the pyrolysis chemical spray deposition technique on ordinary microscope glass substrates preheated to a fixed temperature of 350 °C. After deposition, the films were annealed at temperatures 400 °C for 4h. The aim of this work is on the one hand to study the morphological properties of pure and doped tin dioxide thin films and to determine the different morphological parameters such as: the roughness Ra, Rq and on the other hand to study the effect of Sb doping on the morphological properties of SnO2 thin films. To achieve this purpose, the thickness of all the films was estimated by profilometer with standard scan type. The morphology of the films was examined by atomic force microscope (AFM) in contact mode at room temperature to visualize the surface of our samples (the structure, size and morphology of crystallites ... etc). The 2D and 3D AFM images confirm the formation of nanostructures on the surface, with shapes and dimensions influenced by the amount of antimony doping. All the samples show a polycrystalline morphology, and the grain size progressively decreases with the increase of the Sb concentration (1% and 3%). On the other hand, for high antimony doping (5% Sb) the grains are larger than those observed at 3% doping. The root mean square (RMS) surface roughness values for samples with Sb concentrations (5%) were found to be 8.334 nm.

Efficient removal of tetracycline from water using copper MOFs/bismuth molybdate composite nano adsorbent

A composite nanomaterial comprising of bismuth molybdate and copper-based MOFs (BCuM) was obtained by a facile hydrothermal technique and applied as a nano-adsorbent for the decontamination of wastewater with tetracycline (TC). The nanosorbents' internal elemental constitution, surface morphologic features and internal crystallite structure were analysed using EDS, SEM and XRD techniques. As can be seen from the kinetics of adsorption, the dominating forces of adsorption are chemisorption. At 323 K, the total sorption was in accordance with the Langmuir isotherm reaching 354.610 mg/g. The results of the thermodynamic analysis of the desorption reaction indicate that TC through BCuM occurs spontaneously and is related to an intrinsic heat absorption process. The findings indicated that the BCuM adsorbent showed excellent adsorption over the pH range of 3 ∼ 8 with good reusability. Fourier Transform Infrared (FT-IR) spectroscopy shows that this adsorption is mainly a function of the π-π bonds present in the reaction system of the sorbent and polluting substance. Composite bismuth molybdate nano-adsorbent BCuM of Copper based MOF demonstrated superior adsorption properties and wider application prospects for treating TC from sewage in comparison to single bismuth molybdate nanomaterials.