Ultrasonic Spray Pyrolysis Technique Research Articles

Imparting Chemiresistor with Humidity-Independent Sensitivity toward Trace-Level Formaldehyde via Substitutional Doping Platinum Single Atom.

The modification of metal oxides with noble metals is one of the most effective means of improving gas-sensing performance of chemiresistors, but it is often accompanied by unintended side effects such as sensor resistance increases up to unmeasurable levels. Herein, a carbonization-oxidation method is demonstrated using ultrasonic spray pyrolysis technique to realize platinum (Pt) single atom (SA) substitutional doping into SnO2 (named PtSA-SnO2 ). The substitutional doping strategy can obviously enhance gas-sensing properties, and meanwhile decrease sensor resistance by two orders of magnitude (decreased from ≈850 to ≈2 MΩ), which are attributed to the tuning of band gap and fermi-level position, efficient single atom catalysis, and the raising of adsorption capability of formaldehyde, as validated by the state-of-the-art characterizations, such as spherical aberration-corrected scanning transmission electron microscopy (Cs -corrected STEM), in situ diffuse reflectance infrared Fourier transformed spectra (in situ DRIFT), CO temperature-programmed reduction (CO-TPR), and theoretical calculations. As a proof of concept, the developed PtSA-SnO2 sensor shows humidity-independent (30-70% relative humidity) gas-sensing performance in the selective detection of formaldehyde with high response, distinguishable selectivity (8< Sformaldehyde /Sinterferant <14), and ultra-low detection limit (10 ppb). This work presents a generalized and facile method to design high-performance metal oxides for chemical sensing of volatile organic compounds (VOCs).

Effect of fluorine doping on the improvement of electrical and photocatalytic properties of ZnO films

ZnO:F thin films were produced by ultrasonic spray pyrolysis (USP) technique. For photovoltaic and photocatalytic applications, the properties of ZnO films have been tried to be improved by adding the flourine (F) element. The average optical transmittance was higher than 85%. Photoluminescence (PL) spectra depict blue, green and yellow emission in deposited films. Photocatalytic activity of ZnO and ZnO:F thin films was evaluated with methylene blue (MB) organic pollutant under UV irradiation. 5% doped ZnO:F film successfully decomposed ~ 80% using MB as photocatalyst. The lowest resistivity (3.54 × 10–3 Ωcm), high carrier concentration (2.52 × 1020 cm−3) and high hall mobility (8.28 cm2V−1 s−1) were observed in ZnO:F (5%) film. With this study, it was concluded that F-doped ZnO films were effective in the degradation of MB, which is widely used in the food and pollutant industries. Therefore, it makes ZnO:F films a promising material in both optoelectronic and photocatalytic applications due to their optimum properties.

Fine-tuning SnO2 films: Unleashing their potential through deposition temperature optimization by ultrasonic spray pyrolysis

In this study, the optimization of the deposition temperature, which directly affects the crystallinity, morphology, and electrical conductivity of SnO2 films deposited onto Corning Eagle XG glass substrates using the ultrasonic spray pyrolysis technique, was investigated to tailor their physical properties for various applications. Structural analyses revealed that the films had a tetragonal rutile structure, and while films deposited at lower temperatures exhibited a higher prevalence of (200) oriented planes, yet this decreased with an increase in deposition temperature. Morphological analyses showed that the films consisted of grains with octahedral shapes, and films deposited at lower temperatures were found to be more compact. The films had bandgap energy ranges between 3.96 eV and 4.02 eV. Hall effect measurements revealed that not only the carrier concentration decreased from 4.52 × 1019 cm−3 to 0.80 × 1019 cm−3, but the mobility also decreased from 23.32 cm2/Vs to 12.85 cm2/Vs. Among all the films, it was noted that the films deposited at 350 °C had the highest figure of merit which is 12.3 × 10−4 Ω−1. It can be concluded that the changes underlying these variations are associated with structural and morphological changes depending on the substrate temperature. Also, significant results have been attained in applications where precise control over crystal structure and surface morphology is crucial.

Jettability and printability of customized gold nanoparticles-based ink on flexible substrate through inkjet printing process

Among the different metal nanoparticles for formulating inkjet-based conductive inks, gold remains the best choice for fabricating different patterns on economical and bio-degradable substrates such as commercial photo papers for developing low-cost sensing devices. Formulating customized gold nanoparticle (AuNPs) inks remains challenging as the ink must meet specific physical, chemical and rheological properties to achieve appropriate jettable behaviour and printable characteristics. It should exhibit well-controlled viscoelastic response for the smooth and optimized flow through the nozzles and then cure immediately to facilitate the shape retention of deposited feature. In this work, the jettability window definition framework using dimensionless numbers such as Re, We, Ca, and Z are defined for the aqueous-based AuNPs inks synthesized via ultrasonic spray pyrolysis technique and formulated into three concentration levels of 300, 600, and 1200 ppm. A theoretical CFD based simulation study is conducted to observe the ink droplet formation behaviour at different droplet velocities through inkjet nozzle. Among these formulated inks, 1200 ppm shows the most favourable behaviour as obtained through the simulation and jettability window results. It is tested further to see how different printing settings, like pulse voltage and number of repetitions, affected the continuity and density of the ink, affecting the quality of the printed AuNPs. This work demonstrates the process capabilities of inkjet printing technology by testing the formulated AuNPs ink.

Spray pyrolysis-based synthesis of pure molybdenum powder with nanoscale primary particles and its sintering characteristics

Molybdenum (Mo) is a refractory metal with exceptional high-temperature stability, resistance to creep, and low coefficient of thermal expansion, it thus has great potential for various high-temperature applications. Nevertheless, conventional methods of synthesizing Mo powder, such as mechanical milling and wet chemical processing, have encountered limitations in producing sintered bodies with high relative density and a fine grain structure while maintaining a low sintering temperature. Therefore, it is crucial to develop an efficient powder synthesis method that enables precise and uniform control over the powder's size and shape while minimizing contamination. Such an approach would contribute to achieving excellent formability and sinterability for the resulting Mo sintered body. In this study, we successfully demonstrated the ultrasonic spray pyrolysis (USP) technique in combination with hydrogen reduction for synthesizing pure Mo powder. The resulting Mo powder exhibited micro-sized secondary particles composed of nanoscale primary particles, leading to improved formability and sinterability, essential for fabricating high-quality sintered bodies. In order to comprehensively understand the properties of the as-prepared molybdenum oxide and hydrogen-reduced Mo powder, we employed various methods to analyze its physicochemical characteristics systematically. Subsequently, the fine Mo particles were subjected to a pressureless sintering process after a conventional uniaxial powder molding. Due to its excellent formability and sinterability, we achieved a Mo sintered body with a grain size of approximately 3 μm while maintaining a relatively high sintering density of 98.3% at a comparatively low sintering temperature of 1400 °C. The resulting microstructure contributed to a relatively high hardness of around 234 Hv. These results indicate the successful synthesis of pure Mo powder with desirable properties and highlight its potential in various applications, particularly those requiring high-quality sintered bodies with enhanced hardness.

Fabrication and characterization of green ZnS:Tb AC- electroluminescent devices by ultrasonic spray pyrolysis

MISIM (metal-insulator-semiconductor-insulator-metal) structures of alternating current thin film electroluminescent (ACTFEL) devices were deposited on ATO/glass substrates by the ultrasonic spray pyrolysis technique. Zirconium oxide and terbium doped zinc sulfide were used as dielectric and semiconductor phosphor layers, respectively. A focused ion beam equipment was used to prepare a lamella of the MISIM structure, for cross-sectional scanning electron microscopy analysis in the STEM mode. Chemical analysis by energy-dispersive X-ray spectroscopy (EDS) elemental maps was also made for the identification of the distribution of the elements through the layers composing the MISIM structure. Characteristic Tb3+ emission bands due the 5D4 ->7FJ transitions were obtained by AC voltage application at 10 kHz with the main peak centered at 542 nm. An increase in the electroluminescent intensity and a shift of the CIE coordinates toward a purer green color with increasing the applied voltage was observed. The threshold voltage of these green electroluminescent devices was 46 Vrms, and a luminance up to 41 cd/m2 was obtained for the maximum applied voltage of 76.9 Vrms.

Insight into the photoluminescence and morphological characteristics of transition metals (TM = Mn, Ni, Co, Cu)-doped ZnO semiconductor: a comparative study

In this work, undoped and transition metal (TM = Mn, Ni, Co, Cu)-doped ZnO thin films were grown on Si substrate using the ultrasonic spray pyrolysis technique, adhering to the same deposition conditions to compare their morphological and photoluminescent characteristics. X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), and Photoluminescence (PL) spectroscopy were used to investigate the chemical composition, morphology, and luminescence properties, respectively. XPS results indicate that Mn and Ni ions have bivalent and trivalent electronic states coexisting in the ZnO lattice, Cu ions have both monovalent and bivalent states, and Co ions have only bivalent states. Besides, there is a considerable increase in the level of oxygen vacancies observed upon TM doping. The topographic and phase-contrast AFM images, supported by their associated statistical parameters and mean height distribution histograms, reveal that TM doping increases the tendency for crystalline grains to coalesce in 3D, resulting in a more roughened surface, larger grains with prominent boundaries, increased porosity, and an inhomogeneous height distribution. PL spectra of TM-ZnO show a broadening of the ZnO band gap accompanied by different luminescence behavior compared to pure ZnO regarding both UV and visible emissions. CuZnO is characterized by a green luminescence, CoZnO and MnZnO by a red luminescence, and ZnO and NiZnO by a broad visible luminescence. The possible mechanism for defect luminescence in each TM-ZnO sample was systematically investigated. The chromaticity color coordinates of the PL emissions show that the films provide different color regions well distributed on the CIE chromaticity diagram. The findings regarding the coexistence of two valence states of TM doping, the level of oxygen vacancies, the grain coalescence process, and the luminescence characteristics are carefully correlated and discussed herein.

Morphological Evolution of TiO2 Nanoparticle Deposited on QCM Sensor at Various Calcination Temperature

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. HIGHLIGHTS The size of TiO2 agglomerates and their particles increases as the calcination temperature is raised Higher calcination temperature resulted in a larger frequency shift of the QCM oscillation due to the layer inertial mass increase Larger TiO2 nanoparticle size significantly increases the layer’s resistance, contributing to higher impedance GRAPHICAL ABSTRACT

Improving optical and morphological properties of Mn-doped ZnO via Ar ion sputtering followed by high-temperature UHV annealing

Abstract Using the ultrasonic spray pyrolysis technique, pure (ZnO) and manganese (4at%)-doped zinc oxide (ZnMnO) thin films were synthesized and treated with Ar+ sputtering in the UHV (ultra-high vacuum) system. In this regard, XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy), PL (photoluminescence), and AFM (atomic force microscopy) techniques were applied to investigate the electronic and photonic properties of ZnO. XRD and XPS allowed us to identify the successful incorporation of Mn as a substitute for Zn, while PL and AFM images reveal a high tendency for crystalline grains on theZnMnO surface to aggregate to form small grains. However, bandgap narrowing, a redshift with considerable fluctuations in excitonic emission, and a perfect quenching of visible emission (400–640 nm) were observed. Investigations into defect-related emission in ZnMnO and ZnO compounds were conducted. The PL spectra of the prepared samples were measured and analyzed using Gaussian fitting. The PL of undoped ZnOexhibited an intense broad band with a peak at 550 nm. Two effects were shown to occur as a result of Mn doping: (i) a sharp quenching of self-activated PL with a progressive red-shift of the quenching’s spectral boundary; (ii) the appearance of a new emission band with a peak at 1.64 eV (756 nm), which dominates the PL spectrum and is noted in a band diagram; as well as a slight shift in the main line of ZnO, which is located at energy 3.275 eV (378.57nm).

Zinc doping effects on the microstructural, electrical and optical properties of nanostructured ZnxBi2-xS3 ([formula omitted]) thin films grown by ultrasonic spray pyrolysis

Zinc-doped bismuth sulfide (Bi2-xZnxS3) nanocrystalline thin films were deposited on glass substrates by using an ultrasonic spray pyrolysis (USP) technique and their structural, morphological, electrical and optical properties experimentally addressed. X-ray diffraction (XRD) and micro-Raman spectroscopy have confirmed the generation of a single-phase polycrystalline orthorhombic material. The crystallite size and micro-deformation of the films was found to depend on the dopant concentration. The surface appears condensed and dense with a uniform spatial grain distribution, as revealed by scanning electron microscopy (SEM) images. Energy dispersive X-ray spectroscopy (EDS) studies revealed a certain Bi deficiency in both undoped and Zn-doped films. When the nominal Zn doping concentration increases from x = 0 to x = 0.09, the crystallite size decreases from 30 to 21 nm. The optical band gap of the films increased from 1.62 to 1.65 eV with Zn content increasing up to x = 0.06, then reducing to 1.58 eV for the maximum Zn content. Optical measurements showed a high absorption coefficient (α > 104 cm−1) in the visible and near-infrared ranges. The Urbach energy followed a similar behavior as a function of doping concentration. The electrical conductivity as well as the sheet carrier mobility of the Bi2-xZnxS3 films increase sharply by increasing the Zn content up to x = 0.06. For this doping concentration, mobility reaches 1.37 × 105 cm2/Vs while keeping carrier concentration above 1017 cm−3. Our experimental results provide strong evidence that Zn-doping is a suitable method to increase Bi2S3 light-harvesting efficiency in solar cell devices.

Study of Ni/Y2O3/Polylactic Acid Composite.

This study demonstrates the successful synthesis of Ni/Y2O3 nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray pyrolysis technique. They were collected in a water suspension with polyvinylpyrrolidone (PVP) as the stabiliser. The presence of the Y2O3 core and Ni shell was confirmed with transmission electron microscopy (TEM) and with electron diffraction. The TEM observations revealed the formation of round particles with an average diameter of 466 nm, while the lattice parameter on the Ni particle's surface was measured to be 0.343 nm. The Ni/Y2O3 nanocomposite particle suspensions were lyophilized, to obtain a dried material that was suitable for embedding into a polylactic acid (PLA) matrix. The resulting PLA/Ni/Y2O3 composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/Y2O3 showed a slight average decrease (8.55%) in flexural strength and a small decrease from 3.7 to 3.3% strain at the break, when compared to the base PLA. These findings demonstrate the potential for utilising Ni/Y2O3 nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields.

Physical properties of ZnO:B:Ce nanofiber like thin films prepared by ultrasonic spray pyrolysis technique

Physical properties of ZnO:B:Ce nanofiber like thin films prepared by ultrasonic spray pyrolysis technique

MnPc Films Deposited by Ultrasonic Spray Pyrolysis at Low Temperatures: Optical, Morphological and Structural Properties.

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.

White luminescent emissions from HfO2 and HfO2:Al3+ layers deposited by ultrasonic spray pyrolysis technique

Polycrystalline HfO2 and HfO2:Al3+ coatings were synthesized by the spray pyrolysis technique. The photoluminescence and cathodoluminescence characteristics of the coatings were studied as a function of the synthesis parameters; the temperature of deposition and the dopant content (Al3+ions). A blue, bluish-white and warm white emission was found in the coatings, depending on the substrate temperature, doping concentration and excitation wavelength. The photoluminescence emission was enhanced with the increment of the deposition temperature and a quenching effect was also observed with the dopant concentration. The CIE chromatic coordinates: (0.3067, 0.3462), (0.3091, 0.3502) and (0.3073, 0.3498), were close to the ideal white emission. CCT values for some of the coatings make them potentially useful in white lighting systems. The structural characterization was also carried out by X-ray diffraction, SEM, HRTEM and EDS elemental composition.

Outstanding photoelectrical response in BiFeO3 hollow microspheres deposited by ultrasonic spray pyrolysis technique

Nowadays, it is well known that BiFeO3 exhibits a low photoresponse and, in consequence, small short-circuit current density (Jsc≪μA/cm2). This event is considered a problem for which multiple solutions have been explored, from the formation of complex heterostructures, as well as doping with several materials, alternatives that are expensive and, in many cases, complicated. In this context, we report a simple and low-cost technique (Spray Pyrolysis) that has been carried out to obtain microstructures forming hollow BiFeO3 spheres and circular flower-shaped composed by BiFeO3-Bi2O3 with an outstanding photoresponse. These microstructures show a photocurrent increase of more than six magnitude orders (Jsc=3.5 mA/cm2) and an external quantum efficiency reaching a maximum value of 10.7% at a wavelength of 431 nm applying 0 V (photovoltaic effect). Furthermore, a photoresponse variation is also observed when applying positive or negative electrical polarization. The improvement of the photoelectrical response is attributed to the structure type, composition and the oxygen vacancies present by the same process of formation of these microstructures, which is discussed as an Ostwald ripening and a Kirkendall diffusion process. The morphology of the described microstructures was observed using scanning electron microscopy (SEM), while the structural and compositional analysis were performed using X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. In the case of electrical measurements, an ITO/BFO/Si-n heterojunction was fabricated being this heterojunction formed by intrinsic semiconductor (perovskite) and an n-type oxide semiconductor (ITO).

Fabrication of Li-Doped NiO Thin Films by Ultrasonic Spray Pyrolysis and Its Application in Light-Emitting Diodes

The fabrication of NiO films by different routes is important to extend and improve their applications as hole-transporting layers in organic and inorganic optoelectronic devices. Here, an automated ultrasonic pyrolysis spray method was used to fabricate NiO and Li-doped NiO thin films using nickel acetylacetonate and lithium acetate dihydrate as metal precursor and dimethylformamide as solvent. The effect of the amount of lithium in the precursor solution on the structural, morphological, optical, and electrical properties were studied. XRD results reveal that all the samples are polycrystalline with cubic structure and crystallite sizes in the range of 21 to 25 nm, without any clear trend with the Li doping level. AFM analysis shows that the crystallites form round-shaped aggregates and all the films have low roughness. The optical transmittance of the films reaches values of 60% to 77% with tendency upward as Li content is increased. The electrical study shows that the films are p-type, with the carrier concentration, resistivity, and carrier mobility depending on the lithium doping. NiO:Li (10%) films were successfully incorporated into inorganic light emitting diodes together with Mn-doped ZnS and ZnO:Al films, all deposited on ITO by the same ultrasonic spray pyrolysis technique.

Synthesis and characterization of Zinc Oxide thin films deposited by Spray Pyrolysis technique for possible applications in solar cells

In the present study, the synthesis and characterization of ZnO thin films deposited at 300, 350 and 400°C using the Ultrasonic Spray Pyrolysis technique, as a possible candidate for electron transport layer (ETL) in solar cells is reported. X-ray diffraction (XRD) analysis revealed that the films have a hexagonal wurtzite phase with a preferential orientation (101) with good polycrystallinity. The mean crystallites size based on the Debye-Scherrer model was calculated, indicating that the size of the crystals decreases as the deposition temperature increases. The optical characterization of the material showed a high transmittance in the visible region (85-99%) with which the optical band gap (3.06-3.29 eV) was determined. The thickness, surface roughness and optical constants (n and k) were determined by Spectroscopic Ellipsometry using the Gaussian oscillator model. Hall Effect revealed a low resistivity of 1-4 Ω cm and a high mobility of charge carriers (304 cm2/Vs) in the films. Due to all these properties, ZnO is considered an ideal material for optoelectronic applications, as well as a material with potential to be used as ETL in solar cells.

Hollow microspheres formed by nanograins of Cr[formula omitted]Ti[formula omitted]O[formula omitted] synthesized by ultrasonic spray pyrolysis for acetone detection

The (Cr,Ti)2O3+z system, with corundum structure, has been studied due its technological application as gas or volatile compound detector. In this work we studied Cr1.8Ti0.2O3+z (CTO) particles grown by ultrasonic spray pyrolysis technique. The sample consists on hollow microspheres with a mean diameter of 12.8 μm, and the walls of the spheres are constituted by nanograins. Magnetic susceptibility studies and electron spin resonance spectroscopy showed a para- to antiferromagnetic transition at (306 ± 1) K. The acetone detection experiments were performed on compressed CTO forming a porous pellet. The CTO fabricated by spray pyrolysis detected very well acetone vapours with a linear response with the acetone concentration. This demonstrates that CTO particles produced by ultrasonic spray pyrolysis technique present high potentiality as volatile organic compounds detector. This synthesis route is economical and allows producing a great quantity of material in a short time, making this method adequate for large scale production.

Evaluation of the Piezoresistivity of a Thin Film of ZnO Doped with Fluorine and Deposited via the Ultrasonic Spray Pyrolysis Technique for Applications in Micro/Nano-Electromechanical Sensors

In this study, thin films of zinc oxide doped with fluorine ZnO: F were deposited via ultrasonic spray pyrolysis (USP) with an atomic ratio of [F/Zn] in a starting solution of 15 at.% on borosilicate glass coverslips and SiO2/Si substrates. The structure, electrical resistivity, and thickness were obtained via X-ray diffraction, the four-point technique, and profilometry, respectively. A ZnO: F piezoresistor was modeled at the fixed end of the cantilever through lithography and chemical etching. A SiO2/Si cantilever structure was used to evaluate the piezoresistivity of a ZnO: F thin film, and temperature coefficient of resistance (TCR) measurements were performed in an electric furnace. The strain on the ZnO: F piezoresistor caused by the application of masses at the free end of the cantilever was determined using a theoretical equation, in addition to a simulation in the COMSOL Multiphysics 5.3a FEM (finite element method) software considering the dimensions and materials of the manufactured device. The ZnO: F thin films were hexagonal wurtzite (phase 002), with thicknesses in the range from 234 nm to 295 nm and with resistivities of the order of 10−2 Ω.cm. The ZnO: F thin-film piezoresistor showed a gauge factor (GF) of 12.7 and a TCR of −3.78 × 10−3 %/K up to 525 K, which are suitable properties for sensor development.

Ruddlesden–Popper Oxides LaSrM11−xM2xO4±δ (M1, M2—Fe, Co, Ni) Synthesized by the Spray-Pyrolysis Method as Promising Electrocatalysts for Oxygen Evolution Reaction

Ruddlesden–Popper (RP) transition-metal oxide phases with the general formula An+1BnO3n+1 are versatile functional materials that can accommodate a large variety of compositions without compromising structural stability. Substitutions at the A and B sites allow for the precise control of functional properties of these materials. This opens wide possibilities for rational design. In particular, some of these materials were demonstrated to be efficient and stable catalysts for electrochemical oxygen evolution reaction (OER)—one of the key processes in fuel cells and water electrolyzers. In this work, RP phases LaSrM11−xM2xO4±δ (M1, M2—Fe, Co, Ni) with unreported stoichiometry are prepared from aqueous solutions of metal nitrates using the ultrasonic spray-pyrolysis (USP) technique. We found that the phase purity of samples synthesized by USP is higher as compared to samples prepared by solid-state synthesis or by precipitation from aqueous solutions followed by calcination, used in previous studies of RP oxides. LaSrFe0.5Ni0.5O4–δ (LSNF) oxides are found to be very active in OER in alkaline solutions, with overpotential 0.27 V at j = 0.1 A cm–2 of visible electrode surface in a 5 M solution of KOH. This overpotential is on par with the noble-metal-based OER electrocatalysts. Moreover, the catalytic performance of LSNF in OER is found to be stable over the electrolysis time even in the strongly alkaline solution. These two factors let us conduct the water splitting process in more concentrated electrolytes decreasing the energy cost of hydrogen production by water electrolysis.