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Hydrogen sulfide (H2S) is a highly toxic and corrosive gas commonly found in industrial emissions and natural gas processing, posing serious risks to human health and environmental safety even at low concentrations. The early detection of H2S is therefore critical for preventing accidents and ensuring compliance with safety regulations. This study presents the development of porous ZnO/SnO2-nanocomposite gas sensors tailored for the ultrasensitive detection of H2S at sub-ppb levels. Utilizing a screen-printing method, we fabricated five different sensor compositions—ranging from pure SnO2 to pure ZnO—and characterized their structural and morphological properties through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Among these, the SnO2/ZnO sensor with a composition-weight ratio of 3:4 demonstrated the highest response at 325 °C, achieving a low detection limit of 0.14 ppb. The sensor was evaluated for detecting H2S concentrations ranging from 5 ppb to 500 ppb under dry, humid air and N2 conditions. The relative concentration error was carefully calculated based on analytical sensitivity, confirming the sensor’s precision in measuring gas concentrations. Our findings underscore the significant advantages of mixture nanocomposites in enhancing gas sensitivity, offering promising applications in environmental monitoring and industrial safety. This research paves the way for the advancement of highly effective gas sensors capable of operating under diverse conditions with high accuracy.

This research delves into the comprehensive exploration of silica nanoparticles (SiO2-NPs) synthesis via ultrasonic spray pyrolysis. Essential factors investigated encompassed varying concentrations of tetraethyl orthosilicate (TEOS) (0.51 M, 0.25 M, and 0.12 M), furnace temperatures (200°C, 300°C, and 400°C), carrier gases (Ar, N2, O2), residence times of reactants in the furnace (0.5 sec, 1.5 sec, 5 sec), and solvents (acetone, ethyl acetate, and ethanol). The influence of incorporating F127 in the synthesis process was scrutinized for its role in producing mesoporous silica nanoparticles. Results indicated that an escalation in TEOS concentration from 0.12M to 0.51M at 400°C resulted in a proportional increase in the average particle diameter of SiO2 nanoparticles from 7 nm to 40 nm and the specific surface area decreased from 147 to 97 m²/g, revealing a narrow size distribution. Manipulating the nitrogen flow rate during the furnace process from 100 to 300 ml/min exhibited the capability to yield SiO2 nanoparticles by increasing their particle size to 61nm. Additionally, an extension of the residence time of precursors, achieved through careful regulation of the carrier gas flow rate, yielded a noticeable augmentation in the average particle diameter. Notably, the choice of solvent emerged as a discernible factor, leading to the fabrication of SiO2-NPs with various morphologies. This multifaceted investigation provides valuable insights into the intricacies of silica nanoparticle synthesis, contributing to the understanding of the nuanced interplay of parameters in achieving desired particle characteristics for diverse applications in nanotechnology and materials science. [ABSTRACT FROM AUTHOR]

Cobalt’s pivotal role in global development, especially in lithium-ion batteries, entails driving increased demand and strengthening global trading networks. The production of different waste solutions in metallurgical operations requires the development of an environmentally friendly research strategy. The ultrasonic spray pyrolysis and hydrogen reduction method were chosen to produce nanosized magnetic powders from waste solution based on iron and cobalt obtained during the purification process of used polycrystalline diamond blanks. With specific objectives focused on investigating the impact of reaction temperature and residence time on the morphology, chemical composition, and crystal structure of synthesized nanosized cobalt powders, our research involved 15 experimental runs using two reactors with varying residence times (7.19 s and 23 s) and distinct precursors (A, B, and C). Aerosol droplets were reduced at 600 to 900 °C with a flow rate of 3 L/min of argon and hydrogen (1:2). Characterization via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction revealed that higher temperatures influenced the spherical particle morphology. Altering cobalt concentration in the solution impacted the particle size, with higher concentrations yielding larger particles. A short residence time (7.9 s) at 900 °C proved optimal for cobalt submicron synthesis, producing spherical particles ranging from 191.1 nm to 1222 nm. This research addresses the environmental significance of recovering magnetic particles from waste solutions, contributing to sustainable nanomaterial applications.

Ultrafine Sm2Fe17N3 powders obtained via ball or airflow milling usually exhibit defects and localized demagnetization owing to their irregular morphologies. Therefore, this study employs the ultrasonic spray pyrolysis–reduction diffusion method in conjunction with CaO coating to control the precursor size of the oxides and obtain a size-controllable nearly spherical micronano-sized pure-phase Sm2Fe17N3 magnetic powder. The investigation involved testing and analyzing the microstructure, phase composition, and magnetic properties of the magnetic powder. The results indicate that the influence of hydrogen reduction after calcium oxide coating is crucial for achieving morphology control, and the amount of calcium oxide coating can regulate the size and morphology of the powder; excessive coating can hinder the subsequent calcium reduction and nitriding processes. By using 40 wt% Ca(NO3)2 to coat the composite oxide obtained via ultrasonic spray pyrolysis and by adjusting the reduction diffusion time, further particle refinement can be achieved, ultimately resulting in a nearly spherical strontium iron nitride magnetic powder with a D50 of 0.52 μm. The coercivity of this magnetic powder reaches 9.13 kOe, and the maximum energy product is 27.83 MGOe. This study provides new methods and avenues to address the issues of magnetic powder sintering growth and improve magnetic performance. It also lays the foundation for the further enhancement of the performance of Sm2Fe17N3 magnets.

The effects of Au addition on the acetone response of Cu2O-added porous SnO2 (pr-Cu2O-SnO2) powders, which were synthesized by ultrasonic spray pyrolysis employing polymethyl methacrylate microspheres as a template, were investigated in this study. The 3.0 wt% Au-added pr-Cu2O-SnO2 sensor showed the largest acetone response among all sensors. In addition, the magnitude of the acetone response was much larger than those of the ethanol and toluene responses. The catalytic activities of these gases over Au-added pr-Cu2O-SnO2 powders were also examined to clarify the key factors affecting their acetone-sensing properties. The Au addition increased the complete oxidation activity of all gases, and the complete oxidation activity of acetone was much higher than those of ethanol and toluene. These results indicate that the oxidation behavior during the gas-diffusion process in the sensitive Au-added pr-Cu2O-SnO2 layer of the sensors is quite important in enhancing the acetone-sensing properties.

The effect of powder characteristics on the sintering behaviour and microstructure of densified W by spark plasma sintering and post-hot isostatic pressing was investigated. W powder was prepared by ultrasonic spray pyrolysis of a W precursor and hydrogen reduction, and a commercially available powder was used for comparison. The synthesised W powders were present in the form of large agglomerates composed of nano-sized particles. The densified specimens prepared by ultrasonic spray pyrolysis showed lower relative density and larger grain size than when commercial powder was sintered under the same conditions. Microstructural observation for the specimen sintered using the powder of ultrasonic spray pyrolysis revealed that the relatively large pores are present along the grain boundaries. The observed microstructural features were discussed by sintering behaviour based on the effect of intra-agglomerate and inter-agglomerate pores in the initial powder on densification and grain growth. [ABSTRACT FROM AUTHOR]

Cobalt's pivotal role in global development, especially in lithium-ion batteries, entails driving increased demand and strengthening global trading networks. The production of different waste solutions in metallurgical operations requires the development of an environmentally friendly research strategy. The ultrasonic spray pyrolysis and hydrogen reduction method were chosen to produce nanosized magnetic powders from waste solution based on iron and cobalt obtained during the purification process of used polycrystalline diamond blanks. With specific objectives focused on investigating the impact of reaction temperature and residence time on the morphology, chemical composition, and crystal structure of synthesized nanosized cobalt powders, our research involved 15 experimental runs using two reactors with varying residence times (7.19 s and 23 s) and distinct precursors (A, B, and C). Aerosol droplets were reduced at 600 to 900 °C with a flow rate of 3 L/min of argon and hydrogen (1:2). Characterization via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction revealed that higher temperatures influenced the spherical particle morphology. Altering cobalt concentration in the solution impacted the particle size, with higher concentrations yielding larger particles. A short residence time (7.9 s) at 900 °C proved optimal for cobalt submicron synthesis, producing spherical particles ranging from 191.1 nm to 1222 nm. This research addresses the environmental significance of recovering magnetic particles from waste solutions, contributing to sustainable nanomaterial applications. [ABSTRACT FROM AUTHOR]

The morphology of TiO2 nanoparticles deposited on a QCM sensor is crucial in its mechanical loading. Different heating treatments transform the morphology of TiO2 nanoparticles, affecting the loading and hence shifting the resonant frequency and changing the impedance QCM value. In this research, the deposition of TiO2 nanoparticles was carried out above QCM using the ultrasonic spray pyrolysis (USP) technique with variations in calcination temperature of 200, 230, and 250 °C. The analysis results show that the increase in the agglomeration and particle size causes an increase in the inertial mass of TiO2 nanoparticles. [ABSTRACT FROM AUTHOR]

Due to their unique properties, iron nanoparticles find diverse applications across various fields, including catalysis, electronics, wastewater treatment, and energy storage. Nano-iron particles are mostly sub-micrometer particles that are highly reactive to both air (oxygen) and water, and in nanoparticles (size below 100 nm), it is even more rapid than the bulk material. This characteristic limits its use in inert environments. Iron nanoparticles are not toxic and are mostly used for wastewater treatment. Understanding the hydrogen reduction mechanisms and conditions that lead to the formation of metallic iron particles from iron (III)-nitrate from an aerosol is crucial for enabling their effective utilization. In this work, we studied the hydrogen reduction behavior of Fe2O3 in the absence and presence of additives (SiO2 or Pt). The particles were prepared via ultrasonic spray pyrolysis and hydrogen reduction. The characterization was performed with a scanning electron microscope, energy-dispersive X-ray spectroscopy, and X-ray diffraction. In the absence of additives, the oxygen content of iron oxide particles decreased with increasing temperature from 700 to 950 °C but significantly increased with the doping of 10 mL (40 wt.%) of SiO2. The inhibitory effect of Si on the hydrogen reduction of Fe2O3 formed was more pronounced at 950 °C than at 700 °C. In contrast, the doping of only 5 mL (15 wt.%) of Pt significantly decreased the oxygen concentration in the synthesized particles by catalyzing the reduction reaction of iron oxides at 700 °C. The metallic iron (Fe) product, obtained in the undoped iron oxides run at only 950 °C, was also formed at 700 °C in the Pt-doped Fe2O3 run. [ABSTRACT FROM AUTHOR]

La-doped ZnO (with 0, 1, 5 and 7 wt.% La) thin films were deposited on Si substrates by ultrasonic spray pyrolysis, using frequency of 1.7MHz, and heated at 450°C for 15min. The effect of La addition on the structural and optical properties of ZnO thin films was analysed. X-ray diffraction patterns confirmed that all prepared thin films had a polycrystalline hexagonal wurtzite structure with highly preferred texture in the (002) plane in the case of the ZnO containing 7 wt.% La. Atomic force microscopy analyses confirmed that the surface morphology is affected by La addition and the root mean square (RMS) roughness tended to be higher by increasing La content. The optical band gap energies of the La-doped thin films are smaller than that of the undoped ZnO. The photoluminescence properties of the prepared thin films confirmed that there was a significant redshift of DLE to wavelength of 711 nm when 1wt.% of La was incorporated in ZnO structure. It was proposed that the incorporation of La into the ZnO structure caused the oxygen atoms to have a strong bond with La.

Because of their high mixing entropies, multi-component alloys can exhibit enhanced catalytic activity compared to traditional catalysts in various chemical reactions, including hydrogenation, oxidation, and reduction processes. In this work, new AgCoCuFeNi high entropy alloy nanoparticles were synthesized by the hydrogen reduction-assisted ultrasonic spray pyrolysis method. The aim was to investigate the effects of processing parameters (reaction temperature, precursor solution concentration, and residence time) on the microstructure, composition, and crystallinity of the high entropy alloy nanoparticles. The characterization was performed with scanning electron microscope, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The syntheses performed at 600, 700, 800, and 900 °C, resulted in smaller and smoother spherical particles with a near-equiatomic elemental composition as the temperature increased to 900 °C. With 0.25, 0.1, and 0.05 M precursor solutions, narrower size distribution and uniform AgCoCuFeNi nanoparticles were produced by reducing the solution concentration to 0.05 M. A near-equiatomic elemental composition was only obtained at 0.25 and 0.05 M. Increasing the residence time from 5.3 to 23.8 s resulted in an unclear particle microstructure. None of the five metal elements were formed in the large tubular reactor. X-ray diffraction revealed that various crystal phase structures were obtained in the synthesized AgCoCuFeNi particles.

Mn/TiO2 series selective catalytic reduction (SCR) catalysts with regular spherical shape could be obtained by ultrasonic spray pyrolysis method. The investigation of experimental parameters, such as decomposition temperature and the type and flow rate of carrier gas, showed that a high and stable NOx conversion at 70% could be achieved at 180 °C when the ultrasonic spray pyrolysis temperature was 500 °C and N2 was used as a carrier gas with a flow rate of 2 L/min. The physical and chemical properties of the catalysts were characterized by X-ray diffraction, SEM, and H2-TPR, revealing that a regular spherical structure, a small amount of Mn2O3 crystals, and high redox ability were the important factors affecting the activity of the catalyst. With these properties, Mn(0.5)/TiO2 (500 °C, N2, 2 L/min) exhibited more than 90% conversion at 240 °C with N2 selectivity above 96%.

Lateral flow immunoassays (LFIAs) are a simple diagnostic device used to detect targeted analytes. Wasted and unused rapid antigen lateral flow immunoassays represent mass waste that needs to be broken down and recycled into new material components. The aim of this study was to recover gold nanoparticles that are used as markers in lateral flow immunoassays. For this purpose, a dissolution process with aqua regia was utilised, where gold nanoparticles were released from the lateral flow immunoassay conjugate pads. The obtained solution was then concentrated further with gold chloride salt (HAuCl4) so that it could be used for the synthesis of new gold nanoparticles in the process of ultrasonic spray pyrolysis (USP). Various characterisation methods including scanning electron microscopy, transmission electron microscopy, ultraviolet-visible spectroscopy and optical emission spectrometry with inductively coupled plasma were used during this study. The results of this study showed that the recovery of gold nanoparticles from lateral flow immunoassays is possible, and the newly synthesised gold nanoparticles represent the possibility for incorporation into new products. [ABSTRACT FROM AUTHOR]

This study reports on the successful conjugation of SARS-CoV-2 S1 spike protein fragments with gold nanoparticles (AuNPs) that were synthesised with Ultrasonic Spray Pyrolysis (USP). This method enables the continuous synthesis of AuNPs with a high degree of purity, round shapes, and the formation of a surface that allows various modifications. The conjugation mechanism of USP synthesized AuNPs with SARS-CoV-2 S1 spike protein fragments was investigated. A gel electrophoresis experiment confirmed the successful conjugation of AuNPs with SARS-CoV-2 S1 fragments indirectly. X-ray Photoelectron Spectroscopy (XPS) analysis confirmed the presence of characteristic O1s and N1s peaks, which indicated that specific binding between AuNPs and SARS-CoV-2 S1 spike protein fragments takes place via a peptide bond formed with the citrate stabiliser. This bond is coordinated to the AuNP's surface and the N-terminals of the protein, with the conjugate displaying the expected response within a prototype LFIA test. This study will help in better understanding the behaviour of AuNPs synthesised with USP and their potential use as sensors in colorimetric or electrochemical sensors and LFIA tests. [ABSTRACT FROM AUTHOR]

To improve the electrothermal performances of FTO based films, an ultrasonic spray pyrolysis method was applied to prepare ATO-FTO bilayer films on quartz substrates. The influence of the ATO film thickness on the structure, surface morphology and electrothermal performance of the bilayer films was conducted. Experimental results demonstrate that the prepared bilayer films are highly crystallized with a tetragonal rutile structure. As the thickness of the ATO film layer increases, the orientation along the (200) crystal planes of the film increases. The grain morphology of the film surface changes from a pyramidal shape to blocks gradually. Moreover, the square resistance of the film decreases from 11.03 Ω/sq to 4.75 Ω/sq as the thickness of the ATO film increase from 210 nm to 860 nm. The electric heating test results prove that the electrothermal performance of the bilayer films has been significantly improved. Comparing to the maximum equilibrium temperatures of 265.7 °C and 210 °C at a 20 V bias voltage for FTO and ATO films, a temperature as high as 440 °C can be achieved for ATO-FTO bilayer films with the ATO layer of 860 nm. Besides, the heating efficiency is 3.04x10-4 W/(°C⋅mm²) for ATO-FTO bilayer films, indicating the ATO-FTO bilayer has excellent electrothermal performance with thermal stability [ABSTRACT FROM AUTHOR]

Nanostructured hollow spheres composed of K 0·5 Na 0.5 (W x Nb 1-x)O 3 were synthesized by ultrasonic spray pyrolysis. Correlations between the W-doping content and properties of the [NbO 6 ] octahedra, including morphology, texture, crystalline structure, and polarization were found. Scanning and transmission electron microscopy analysis indicate the present samples are nanostructured hollow spheres. Textural analysis indicates the samples are composed of a balanced framework including micropores (40–50%) and mesopores (50–60%). Structural refinement by the Rietveld method indicated that non-isovalent W6+ cation only occupies the Nb5+ site in the host structure. Several space groups including Amm 2, Pbcm , and Pm were used to refine the W-doped K 0·5 Na 0·5 NbO 3 structure and the best adjustment was reached assuming the co-existence of two distinct symmetries. The FTIR bands associated with a corner-shared NbO 6 octahedron suggested an increase in Nb–O bond length in agreement with the Rietveld refinement. In general, ultrasonic spray pyrolysis is an effective methodology for the one-step synthesis of nanostructured crystallites of W-doped niobate-based perovskites with a tailored structure and morphology. [ABSTRACT FROM AUTHOR]

In this study, a low-sophistication low-cost spray pyrolysis system built by undergraduate students is used to grow aluminum-doped zinc oxide thin films (ZnO:Al). The pyrolysis system was able to grow polycrystalline ZnO:Al with a hexagonal wurtzite structure preferentially oriented on the c-axis, corresponding to a hexagonal wurtzite structure, and exceptional reproducibility. The ZnO:Al films were studied as transparent conductive oxides (TCOs). Our best ZnO:Al TCO are found to exhibit an 80% average transmittance in the visible range of the electromagnetic spectrum, a sheet resistance of 32 Ω/□, and an optical bandgap of 3.38 eV. After an extensive optical and nanostructural characterization, we determined that the TCOs used are only 4% less efficient than the best ZnO:Al TCOs reported in the literature. This latter, without neglecting that literature-ZnO:Al TCOs, have been grown by sophisticated deposition techniques such as magnetron sputtering. Consequently, we estimate that our ZnO:Al TCOs can be considered an authentic alternative to high-performance aluminum-doped zinc oxide or indium tin oxide TCOs grown through more sophisticated equipment.

An optimum route to synthesis the W-based composite powders with homogeneous dispersion of oxide nanoparticles was investigated. The La2O3 dispersed W powder was synthesized by ultrasonic spray pyrolysis using ammonium metatungstate hydrate and lanthanum nitrate. The dispersion of Y2O3 nanoparticles in W- La2O3 powder was carried out by a polymer addition solution method using yttrium nitrate. XPS and TEM analyses for the composite powder showed that the nano-sized La2O3 and Y2O3 particles were well distributed in W powder. This study suggests that the combination processing of ultrasonic spray pyrolysis and polymeric additive solution is a promising way to synthesis W-based composite powders.

Abstract In this work, we have investigated the structure, morphology, photoluminescence, photocatalytic and photocurrent properties of ZnO thin films as a function of their film thickness (tZnO) fabricated via ultrasonic spray pyrolysis technique. The X-Ray diffraction patterns exhibited the formation of polycrystalline wurtzite phase of ZnO. Scanning electron microscopy images showed the uniform morphology with nanorod structure. The photosensitivity and photocatalytic efficiency are found to be optimum at tZnO = 1200 nm and are attributed to the improved photogeneration of charge carriers and higher concentration of oxygen vacancies. A direct correlation is established between the photosensitivity and photodegradation process. The incident photon-to-electron conversion efficiency (IPCE) and photocatalytic efficiency for the ZnO film at tZnO = 1200 nm are estimated to be 31.5% and 100% respectively. The obtained result suggests that ZnO thin films are potential candidates for applications in various optoelectronic devices.

Here, a specific metal oxide (CuO) and its impurity (Cr) added composites were grown onto glass substrates as nanostructured thin films by executing ultrasonic spray pyrolysis method. The effects of the varied Cr dopant concentration on the morphological, structural, optical and H 2 gas sensor properties of the synthesized CuO thin films were determined by conducting scanning electron microscopy, X-ray Diffraction, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, ultraviolet–visible spectroscopy, and gas detection analyses. The X-Ray Diffraction analysis revealed the presence of CuO crystals with predominant (111) plane and it changed to (002) orientation for the doped samples, where crystallite sizes varied between 32 and 46 nm. The structural studies disclosed that the crystalline structure modified due to the added impurities. The scanning electron microscopy observations unveiled polyhedron-like shape formations of the synthesized nanostructures which also showed clear indications of changed morphology due to the impacts of different Cr doping percentages. Besides, the presence of copper, oxygen, and chromium was confirmed by EDX elemental analysis as well as X-ray photoelectron spectroscopy. The optical examination concluded that absorbance values followed a random trend with respect to the increased impurity contents while bandgap decreased with the increase of doping concentration. And, it was also noted that the luminescent emission peaks decreased in the photoluminescence spectroscopy as a result of introduced impurity levels. Finally, H 2 responsivity was detected for the grown films and found out that the impurity doping notably increased the sensitivity of the gas sensor based on the prepared CuO nanostructures. • USP technique performed to synthesize Cr doped CuO films and H 2 gas sensitivity of the films tested for the first time. • Different impurity percentages noted to cause modifications in the structural parameters of CuO nanostructures. • Cr addition led to decrease the bandgap of CuO samples from 1.75 to 1.59 eV. • The PL emission intensities found to decrease as a result of Cr doping. • The H 2 gas sensitivity of CuO films enhanced due to the presence of added Cr ions. [ABSTRACT FROM AUTHOR]

In this work, we report how manganese phthalocyanine (MnPc) films obtained using the ultrasonic spray–pyrolysis technique at 40 °C deposited on glass substrate subjected to thermal annealing at 100 °C and 120 °C. The MnPc films were characterized using UV/Vis spectroscopy, Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The absorption spectra of the MnPc films were studied in a wavelength range from 200 to 850 nm, where the characteristic bands of a metallic phthalocyanine known as B and Q bands were observed in this range of the spectrum. The optical energy band (Eg) was calculated using the Tauc equation. It was found that, for these MnPc films, the Eg has the values of 4.41, 4.46, and 3.58 eV corresponded to when they were deposited, annealing at 100 °C and 120 °C, respectively. The Raman spectra of the films showed the characteristic vibrational modes of the MnPc films. In the X-Ray diffractograms of these films, the characteristic diffraction peaks of a metallic phthalocyanine are observed, presenting a monoclinic phase. The SEM images of these films were studied in a cross-section obtaining thicknesses of 2 μm for the deposited film and 1.2 μm and 0.3 μm for the annealed films at 100 °C and 120 °C. Additionally, in the SEM images of these films, average particle sizes ranging from 4 to 0.041 µm were obtained. The results agree with those reported in the literature for MnPc films deposited by performing other techniques. [ABSTRACT FROM AUTHOR]

Aluminum-doped zinc oxide (AZO) has electrical conductivity and visible light transmittance similar to those of indium tin oxide that is used in modern display devices at a lower price. Thus, many studies regarded it as an alternative material for transparent conductive oxide coating. This study has integrated atmospheric microplasma with an ultrasonic spray pyrolysis deposition system to prepare economically and rapidly AZO using zinc chloride and aluminum chloride as precursors. The low electrical resistivity of the coating prepared in this system is proposed to be due to free radicals and reactive oxygen. They are generated by the atmospheric plasma that is adsorbed to the layer, thereby decreasing oxygen vacancy and free carrier concentration. Vacuum annealing heat treatment was used to improve the properties of the coating; the resistivity of argon-annealed AZO was 5. 2 ± 1. 1 × 1 0 − 3 Ω –cm with 80% transmittance, thus meeting the transparent conducting oxide requirements. [ABSTRACT FROM AUTHOR]

ZnO is a versatile material and tailoring its physical properties to the field of application is technologically crucial. Intentionally doping with a foreign element is the most common and useful method for that. In this presented work, ZnO films doped at different Mg concentrations (0%, 5%, 10%, and 15%) were deposited onto glass substrates by ultrasonic spray pyrolysis in order to investigate the effect of Mg doping. AFM and SEM images captured for the morphological investigations revealed that Mg doping deteriorated the surface of the films. The structural analysis showed that the Mg doping at 5% enhanced the structural properties, but the crystallization level was adversely affected at higher Mg concentrations. Optical band gap and Urbach energies increased from 3.30 eV to 3.45 eV and from 79.5 meV to 119.8 meV, respectively. The lowest electrical resistivity was noted as 8.72101 cm for Mg-doped ZnO films at 5%. [ABSTRACT FROM AUTHOR]

In this work, a new method of preparing gadolinium oxide by citric acid-assisted ultrasonic spray pyrolysis combined calcination process was investigated. During the pretreatment process, the loose morphology of the precursor was obtained, which could be conducive to the escape of gases from the reaction. And the formation mechanism of the gadolinium oxide shows that citric acid dramatically reduced the calcination temperature required for GdOCl to convert to Gd2O3. In particular, the optimum mass ratio of citric acid to GdCl3 should exceed 1:2. After the calcination process, the Gd2O3 powders with a purity of 99 wt% were obtained. Importantly, we further verified the feasibility of this process in industrial production by using the factory acid-containing extract as raw material. The results of industrial experiments show that this method can eliminate the traditional precipitation process and has the potential to replace the existing industrial processes. To effectively preparing the gadolinium oxide, a novel process using citric acid-assisted ultrasonic spray pyrolysis was investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] Current–voltage characteristics of nanostructured vanadium oxide bronze β-NaV 6 O 15 obtained from oxalate solutions by ultrasonic spray pyrolysis (USP) under various conditions were studied. The conditions of USP synthesis significantly affected the particle morphology, specific surface area, defect structure and oxidizing ability of the compound. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) have now been used in skin care creams for several years, with marketed anti-aging, moisturizing, and regenerative properties. Information on the harmful effects of these nanoparticles is lacking, a concern for the use of AuNPs as cosmetic ingredients. Testing AuNPs without the medium of a cosmetic product is a typical method for obtaining this information, which is mainly dependent on their size, shape, surface charge, and dose. As these properties depend on the surrounding medium, nanoparticles should be characterized in a skin cream without extraction from the cream's complex medium as it may alter their physicochemical properties. The current study compares the sizes, morphology, and surface changes of produced dried AuNPs with a polyvinylpyrrolidone (PVP) stabilizer and AuNPs embedded in a cosmetic cream using a variety of characterization techniques (TEM, SEM, DLS, zeta potential, BET, UV–vis). The results show no observable differences in their shapes and sizes (spherical and irregular, average size of 28 nm) while their surface charges changed in the cream, indicating no major modification of their primary sizes, morphology, and the corresponding functional properties. They were present as individually dispersed nanoparticles and as groups or clusters of physically separated primary nanoparticles in both dry form and cream medium, showing suitable stability. Examination of AuNPs in a cosmetic cream is challenging due to the required conditions of various characterization techniques but necessary for obtaining a clear understanding of the AuNPs' properties in cosmetic products as the surrounding medium is a critical factor for determining their beneficial or harmful effects in cosmetic products. [ABSTRACT FROM AUTHOR]