The synthesis of homogenous powder mixtures and the characteristic of the sintered W-0.4 wt% Ni compacts were investigated. Ultrasonic spray pyrolysis and polymeric additive solution route for ...developing the initial powder mixtures were compared based on the resulting microstructure and mechanical property of sintered WNi. The powder mixture synthesized by the ultrasonic spray pyrolysis and hydrogen reduction showed marked refinement of W particle size and homogeneous dispersion of the Ni activator in the form of nickel hydroxide. The WNi powder from ultrasonic spray pyrolysis, pressureless-sintered at 1400 °C, exhibited the increased relative density of 97.6% and hardness of 4.02 GPa compared with the powder from polymeric additive solution. XPS analysis revealed that Ni, existed as nickel hydroxide state in the powder mixture, was partially dissolved in W during sintering to form an alloy. The increase in relative density was explained by the uniform WNi nanocomposite powder synthesized by ultrasonic spray pyrolysis. The high hardness was mainly due to the refinement of W grains.
•WO3-NiO powder was prepared by ultrasonic spray pyrolysis (USP).•W-NiO powder was prepared by polymeric additive solution method.•Hydrogen reduction was performed to obtain WNi nanoparticles.•WNi nanoparticles obtained by USP has a finer particle size.•WNi sintered body obtained by USP has a higher relative density and hardness.
Lead-free FTO/TiO2/MASnBr3/P3HT/Ag perovskite solar cells (PSCs) were fabricated by a fully ultrasonic spray pyrolysis (USP) method. The MASnBr3 thin films had very large grains (clusters) up to ...15 μm. The crystal/crystallite size of the films was determined from the XRD pattern as 112.7 nm. The coating of MASnBr3 and P3HT layers was carried out on a large area of 36 cm2. The champion cell with an active area of 0.30 cm2 has an open circuit voltage of 0.370 V, a short circuit of 0.460 mA/cm2, a fill factor of 57.2%, and a power conversion efficiency of 0.097%. The production of all layers with the USP method is important to the commercialization of the lead-free PSCs.
Copper tin sulphide (CTS) is an important material used as an absorber layer for low cost solar cells. Variation of the elemental constituents of CTS and the substrate temperature cause a significant ...alteration in its electronic property, which may cause unpredictable change in the device efficiency. In view of the same, an electronic property predictor for CTS is developed in this work based on real-time experimental data for accurately predicting the resistivity, mobility, carrier concentration and bandgap with variation in the atomic constituents of CTS and the substrate temperature. Seven machine learning (ML) algorithms are in-built in the predictor. Prediction performance is carried out with all these ML models on the basis of mean absolute percentage error (MAPE), coefficient of determination (R2) and root mean square error (RMSE). Decision Tree is found to be the best in accuracy towards predicting the resistivity (MAPE - 1.634 Ωcm, R2 - 0.93 and RMSE = 0.049Ωcm), XGBoost in predicting the mobility (MAPE - 0.567 cm2/Vs, R2 - 0.409, RMSE- 0.429 cm2/Vs) and Random Forest in predicting the bandgap (MAPE- 0.017 eV, R2 - 0.863, RMSE - 0.051 eV) and the logarithmic values of carrier concentration (MAPE - 0.006, R2 - 0.715, RMSE - 0.562). The results so obtained are from limited number of 199 data samples and addition of more data can further boost the accuracy. This know-how of electronic property thus becomes a very crucial factor in accurately determining the absorption coefficient of a particular CTS sample and its role in enhancing the solar cell efficiency.
•Electronic property predictor of Cu2SnS3 (CTS) is developed in this work based on based on real-time experimental data.•It is used for accurately predicting resistivity, mobility, bandgap and carrier concentration.•The prediction is based on the variation of atomic percentage of copper, tin, sulphur and the substrate temperature.•Seven machine learning algorithms are in-built in the predictor.•Decision tree is found to be the best in accurately predicting resistivity.•Mobility is best predicted by XGBoost method.•Random forest is best in predicting bandgap and logarithmic values of carrier concentration.•This predictor system can be utilized to evaluate the quality of CTS thin film for application in solar cell absorber layer.
•A novel one step ultrasonic spray pyrolysis method was developed.•Hollow porous carbon microsphere was synthesized by one step method.•Hollow porous carbon microspheres exhibit good adsorption ...capacity for rhodamine B.•Adsorption mechanism is the pore filling, hydrogen bond, and surface adsorption.
Cerium-based porous carbon microsphere (Ce/PCM) was synthesized by one step ultrasonic spray pyrolysis (USP), and the structure was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and Raman spectrometer. Furthermore, the adsorption performance of Ce/PCM was tested by Rhodamine B. (Rh B). The characteristic’s results showed the structure and specific surface area of Ce/PCM were affected by the pyrolysis temperature, and 800-Ce/PCM had the maximum specific surface area as 472.9 m2·g−1. The adsorption evaluation showed that 800-Ce/PCM had the best removal efficiency, and the maximum adsorption capacity was as high as 508.2 mg·g−1. The results suggested the adsorption kinetics of Ce/PCM for Rh B follows pseudo second-order dynamics and Freundlich model, which indicated that the adsorption process includes chemical adsorption and multilayer adsorption. Kinetic thermodynamic studies proved the absorption was endothermic reaction. The analysis of absorption mechanism indicated that the removal mechanism mainly includes pore filling, hydrogen bonding and surface adsorption.
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•Oxygen-deficient TiO2-x NPs are prepared by one-pot ultrasonic spray pyrolysis.•The one-pot synthesis mechanism for NPs with bulk defects is specifically proposed.•High-concentration ...bulk defects demonstrate to promote photo-to-heat conversion.•Black TiO2-x shows good an evaporation rate of 2.12 kg m-2h−1 due to bulk defects.•The higher evaporation rate is achieved in black TiO2-x compared to carbon black.
While black TiO2-x nanoparticles (NPs) have emerged as promising photothermal materials due to exceptional light absorption properties and intrinsic stability for reliable interfacial water evaporation (IWE) system, their lower evaporation rate (0.8–1.53 kg m-2h−1) than carbon materials remains a significant challenge. This poor evaporation rate is attributed to the low photo-to-heat conversion property of black TiO2-x nanoparticles with a microstructure containing oxygen vacancies exclusively in the surface region—a consequence of the common reduction-based synthesis process. Herein, we achieved an outstanding evaporation rate of 2.12 kg m-2h−1, significantly higher than previous results under 1sun illumination due to the high-concentration bulk oxygen vacancies that promote the photo-to-heat conversion of black TiO2-x nanoparticles. Moreover, it demonstrated that black TiO2-x NPs exhibited a higher evaporation rate than carbon black, a typical carbonaceous photothermal material, under identical conditions. Furthermore, an innovative synthesis method utilizing the ultrasonic spray pyrolysis (USP) process and synthesis mechanism is proposed to introduce high-concentration bulk oxygen vacancies. This method overcomes the unavoidable drawbacks of conventional reduction-based synthesis methods, including surface-concentrated oxygen vacancies of the black TiO2-x. This work provides valuable insights into the defect engineering of metal oxides for high-performance photothermal materials.
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•Sr0.9−x−y−zCa0.1In2O4:(xEu3+, yTm3+, zTb3+) were obtained quickly and continuous.•The relationship between the structural and photoluminescence changes were ...studied.•Sr0.9−x−y−zCa0.1In2O4:(xEu3+, yTm3+, zTb3+) exhibited emission in the white region.
In the present work, Sr0.9−x−y−zCa0.1In2O4:(xEu3+, yTm3+, zTb3+) particles were synthesized by the ultrasonic spray pyrolysis (USP) method to obtain a single-phase white phosphorus formed by six different cations in solution within the lattice (superstructure). The samples were also structurally and morphologically characterized by X-ray diffraction (XRD) techniques and by field emission scanning electron microscopy (FE-SEM). The photoluminescent behavior and the characteristics of the emitted colors were studied by the variation in the co-doping of the rare earth elements. The Sr0.9Ca0.1In2O4 sample showed a near blue color emission, but all co-doped samples showed emission in white with very close chromaticity coordinates to the standard white (x = 0.33 and y = 0.33). The Tm3+ → Tb3+ (ET1), Tm3+ → Eu3+ (ET2) and Tb3+ → Eu3+ (ET3) Energy Transfers were proposed and are considered necessary for adjusting and controlling the desired color properties.
(Ni,Co)Al2O4 mesoporous spinel particles with a high specific surface area were synthesized in a single-step by ultrasonic spray pyrolysis at 1000 °C. After reduction, a uniform metal distribution ...was obtained on the support, which was used as a catalyst for dry and steam reforming of methane. Substituting Ni with Co resulted in a substantial increase in the specific surface area from 118 m2/g to 182 m2/g as a result of different decomposition paths that occurs for Ni and Co salts in the pyrolysis reactions. Results show that partial substitution of Ni with Co, between 20 and 50%, significantly increased the methane conversion values and improved the stability of the catalysts in the time on stream experiments. It also shows that partial substitution substantially improved the catalyst resistance against carbon deposition in the dry reforming process. The complete replacement of the cobalt with nickel in spinel structure caused a significant drop in catalytic properties.
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•NixCo1-xAl2O4 synthesized by a single-step spray pyrolysis as DRM and SRM catalyst.•Uniform Ni/Co nanoparticles was formed over the highly porous Al2O3 after reduction.•Co improved the CH4 conversion and hydrogen yield of the catalysts.•Spray pyrolysis and Co addition improved the morphological feature of the catalyst.
•Porous hollow spheres of BiVO4 were synthetized by ultrasonic spray pyrolysis.•N2 flow, CMC concentration and calcination temperature as synthesis variables.•L·m-1 N2 enables the formation of ...spherical hollow porous particles of BiVO4.•BiVO4 synthetized by USP performed three times greater compared to coprecipitation.•BiVO4 synthetized by USP efficiently promote the photogenerated-carrier separation.
Brain-like nanostructures of BiVO4 were synthesized by ultrasonic spray pyrolysis (USP) using citric acid as chelating agent at 350 °°C. Synthesis variables such as carrier gas flow, structural agent concentration and temperature were herein studied. The samples were characterized by XRD, SEM, TEM, UV–Vis DRS and N2 physisorption. Particularly, HRTEM was used to calculate the crystallite size, d-spacing and assigned plane of all BiVO4 samples. The photoactivity of the as-synthesized BiVO4 was measured during the degradation of methyl orange under visible-light irradiation, while the hydroxyl radical production was rated in terms of its reactivity against terephthalic acid. The morphology of the samples revealed that the use of small flow of N2 allows the formation of spherical hollow porous particles with brain-like structure with slightly smaller crystallite size. The photocatalytic activity of the BiVO4 photocatalysts prepared by USP displayed a performance three times greater compared to the powders produced by co-precipitation. The PL spectra measured revealed that the charge separation process of the BiVO4 powders synthesized by the USP technique was better compared to those obtained by co-precipitation. The energy diagram of the photocatalyst reveals that the usage of the USP technique does not require the formation of a heterojunction to efficiently promote the separation of photogenerated carriers, since it removes defects in the gap which generating states which that induce the recombination; and shorten down the transferring distance from the excitation zone to the active site on the surface of the BiVO4 due to the production of nanostructures.
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Supported gold catalysts have drawn great attention for many decades due to their outstanding performance in remedying the environment from carbon monoxide (CO) pollution. In this ...study, due to the large surface area of spongy Fe2O3, fabricated by salt-assisted ultrasonic spray pyrolysis, a considerable amount of Au was loaded on spongy Fe2O3 compared to low-surface-area non-spongy Fe2O3. It is seen that the spongy Fe2O3 catalyst loaded with Au has an interface that can be extremely active for CO desorption and O2 activation. That means it has high catalytic activity in CO oxidation than non-spongy and low surface area Fe2O3 loaded with Au. Also, the incorporation of Au in low alkaline condition further enhances the interaction between Au and Fe2O3, providing more active sites. This made the catalyst to have better activity, good stability over 60 hrs, and there was no carbonate on its surface. It had full conversion at 30 °C on 120 L g-1h−1 with high TOF (2.2 s−1).
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