One-step Combustion Method Research Articles

La0·8Mn0·2FeO3 impregnated ceramic membrane for membrane fouling elimination via peroxymonosulfate activation

To endow SiC ceramic membranes a catalytic self-cleaning capability, a pore-functionalized SiC ceramic membrane with impregnated a perovskite-type catalyst La0·8Mn0·2FeO3 was fabricated by a urea-assisted one-step combustion method. Diffraction of X-ray (XRD), canning electronic microscopy (SEM) with an energy dispersion X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were employed to investigate the effects of the impregnating of La0·8Mn0·2FeO3 on SiC membrane pore-structure (La0·8Mn0·2FeO3-CM). The catalytic self-cleaning performance of the as-prepared membranes was assessed through peroxymonosulfate (PMS) activation under a cross-flow filtration mode. Results indicate that La0·8Mn0·2FeO3 has been successfully impregnated into the macropores of SiC membranes without pore blocking, and 92.4 % of the flux recovery rate (FRR) was achieved when the PMS concentration was 70 mM and catalytic flushing time was 45 min. Therefore, the La0·8Mn0·2FeO3 impregnated SiC membrane exhibited excellent catalytic self-cleaning property, which can effectively avoid the environmental pollution and the deterioration of membrane materials caused by chemical cleaning for membrane fouling. In addition, the radical quenching experiment and electron spin resonance (EPR) tests were conducted in the catalytic self-cleaning process, and the results suggested that the hydroxyl radical (⋅OH) and sulfate radical (SO4•‾) are simultaneously captured and ⋅OH is the dominant active species. This study embarks on a novel and environmental friendly membrane cleaning approach for irreversible fouling eliminates in diverse membrane separation applications.

Magnetically separable Cu-Fe nanophotocatalyst with enhanced photocatalytic performance under visible-light irradiation: Optimizing the fuel type and heating approach in the synthesis process

This study aimed to examine the influence of fuel type and heating technique on the solution one-step solution combustion synthesis of CuFe2O4 spinel-type photocatalysts. The primary goal was to establish the best configuration of nanophotocatalysts with desirable characteristics, leading to improved photodegradation of dye pollutants when exposed to simulated solar radiation. Cu-spinel nanophotocatalysts were generated using a one-step combustion method involving three distinct fuels (urea, glycine, and citric acid) and two heating strategies (microwave and muffle furnace). The synthesized nanophotocatalysts were characterized through a range of tests, including XRD, FESEM, EDX, BET-BJH, FTIR, VSM, PL, DRS, and pHpzc analyses. During the simulated irradiation of sunlight, the efficacy of the Cu-spinel photocatalyst was evaluated using high-concentration Congo red, a widely used textile dye. Test results indicate that the Cu-spinel nanophotocatalyst formed utilizing glycine and microwave combustion displayed a desirable photocatalytic activity by degradation of 97 % of Congo red in 100 min. In addition, the photocatalytic efficiency of Congo red degradation was significantly enhanced compared to the other fuels and the conventional heating approach. Furthermore, CuFe(G-MW) demonstrated high stability throughout four cycles. Finally, a proposed mechanism for the degradation of Congo red using a CuFe(G-MW) nanophotocatalyst was presented.

Constructing a 3D interlinked network with magnetic/dielectric loss and electron/phonon co-transfer in MgO@Ni@C and MgO@Ni@CNT foams for low loads and prominent thermal/electromagnetic performance

Currently, most existing electronic packaging materials are not efficient enough to be widely utilized due to their high load and incompatibility between heat conductivity (HC) and electromagnetic wave absorption properties (EMWAPs). In response to this, the present study adopts a one-step combustion method to develop MgO@Ni@C and MgO@Ni@CNT foams as advanced multifunctional fillers. The hybrid foams are porous and magnetic, which is related to in-situ generated gas bubbles. By modulating the Ni2+ molar content (φ), combustion temperature (Tc), and C types, the products can achieve a low load with a simultaneous enhancement in HC and EMWAPs. Our results show that the MgO@Ni@C foams formed at φ = 30 mol% and Tc = 800 °C exhibit exceptional HC and EMWAPs (HC = 3.83 W/m⋅K, EABW/d (the ratio of effective absorption bandwidth to thickness) = 5.48 GHz/mm, RLmin = − 59.75 dB, and load = 30 wt%). The MgO@Ni@CNT foams with a dual 3D interlinked network bear a high HC (3.94 W/m⋅K, 5 wt% load) and a large EABW/d (4.0 GHz/mm, 20 wt% load). The increased HC is related to low phonon-scattering, prolonged mean free paths, and continuous phonon/electron co-transfer paths resulting from low defects, small SBET, moderate Ni0, and 3D interlinked network. The improved EMWAPs are credited to high attenuation and matching performance caused by ferromagnetic/exchange resonances, various polarizations, and multiple scattering. Notably, the comprehensive properties of MgO@Ni@C and MgO@Ni@CNT foams are superior to those of other previously reported fillers, suggesting that they can be extensively applied as multifunctional materials in electronic devices.

Nanoarchitecturing hydrogen electrode with intimately coupled ion-conducting and catalytic phases for enhanced intermediate-temperature steam electrolysis

Intermediate-temperature solid oxide electrolysis cells (IT-SOECs) have recently attracted great interest in steam electrolysis. However, the performance of IT-SOECs is substantially influenced by the polarization loss encountered at the traditional hydrogen electrode interface. Herein, we reported an innovative approach to address this challenge by modifying the interface of hydrogen electrode and electrolyte. NiO-BaZr0.1Ce0.7Y0.2O3-δ (NiO-BZCY) nanocomposite with an even distribution of NiO and BZCY was synthesized by a one-step combustion method and utilized to fabricate a hydrogen electrode functional layer (HFL). In comparison with the conventional hydrogen electrode fabricated by the ball-milling method, the developed double-layer hydrogen electrode structure exhibits a gradient porosity with macropores at the electrode substrate and micropores at HFL. The optimized electrode microstructure provides both adequate gas diffusion pathway and enlarged three-phase-boundary for effective electrochemical reaction. Consequently, the polarization loss is significantly reduced, leading to a discernible enhancement in the electrolysis performance of the IT-SOECs.

Facile Synthesis and Biophysical Characterization of Novel Zinc Oxide/Fe3O4 Hybrid Nanocomposite as a Potentially Active Agent in Sunscreens

Zinc oxide nanoparticles (ZnO NPs) are attractive sunscreens for UV protection, but they still face some challenges due to their white color and skin whitening, and the extent of UV blocking is still limited to UV-B. Therefore, the present work aimed to develop novel sunscreen agents based on ZnO/Fe3O4 hybrid nanocomposites. ZnO/Fe3O4 hybrid nanocomposites were prepared using a facile one-step combustion method and characterized by XRD, FTIR, FESEM, and UV–Vis diffuse reflectance techniques. The in vitro sun protection factor (SPF) and antioxidant activity of the prepared samples were carried out by spectrophotometric methods. The biocompatibility potential was tested on the normal (Human lung fibroblast: WI38) and cancerous (Hepatocellular carcinoma: HEPG-2) cell lines and the antibacterial activity was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Bare ZnO NPs and ZnO/Fe3O4 hybrid nanocomposites had pure structures with average particle sizes on a scale below 100 nm. The samples had antibacterial and antioxidant activity as well as the potential for biocompatibility and anticancer activity (cell viability was 80% for all nanocomposites up to 6.25 μg/mL indicating non-toxicity). The nanocomposite presented good UV absorption and SPF values (SPF = 12.2–14) not too far from those of bare ZnO (SPF = 15.4) and achieved extended protection over the UV and visible range. ZnO/Fe3O4 hybrid nanocomposites are colored compounds that can match a desired tanned skin tone and have biophysical properties that make them a promising future as a cosmetic UV protectant.

Self-assembled triple-conductive La2Ni1 − xCe2xO4+δ cathodes for proton-conducting solid oxide fuel cells

A novel composite cathode with triple conductivity and excellent stability is prepared for proton-conducting SOFCs using one-step combustion method. The dual phase composite cathode presents an excellent performance of 1516 mW cm−2 at 700 °C.

Fast synthesis of porous iron doped CeO2 with oxygen vacancy for effective CO2 photoreduction

The activity of photocatalytic CO2 conversion to carbon-containing products is determined by the adsorption and activation of CO2 molecules on the surface of catalyst. Here, iron doped porous CeO2 with oxygen vacancy (PFeCe) was prepared by one-step combustion method. The amount of CO2 adsorbed via using the porous structure has been significantly increased in the case of a relatively small specific surface area and CO2 molecules are more easily captured and undergo a reduction reaction with photoinduced carriers. In addition, oxygen vacancies are formed in the iron doped CeO2 lattice as the active sites for CO2 reduction, which can form strong interactions with CO2 molecules, thereby effectively activating CO2 molecules. The reduction products of CO2 over PFeCe composite are CO and CH4, which is approximately 9.0 and 7.7 folds than that of CeO2. This work offers insights for the construction of efficient ceria-based photocatalysts to further achieve robust solar CO2 conversion.

CO2 Conversion into N-Doped Porous Carbon-Encapsulated NiO/Ni Composite Nanomaterials as Outstanding Anode Material of Li Battery.

N-doped porous carbon encapsulated NiO/Ni composite nanomaterials (N-doped NiO/Ni@C) was successfully obtained by a one-step solution combustion method. This study demonstrates a one-step combustion method to synthesize n-doped porous carbon encapsulated NiO/Ni composite nanomaterials, using carbon dioxide as the carbon source, nickel nitrate as the nickel source, and hydrazine hydrate as the reaction solution. Spherical NiO nanoparticles with a particle size of 20 nm were uniformly distributed in the carbon matrix. The load of NiO/Ni can be controlled by the amount of nickel nitrate. The range of carbon content of recovered samples is 69–87 at%. The content of incorporated nitrogen for recovered samples is 1.94 at%. As the anode of lithium ion battery, the composite material exhibits high capacity, excellent multiplier performance and stable circulation performance. N-doped NiO/Ni@C-2 was applied to lithium ion batteries, and its reversible capacity maximum is 980 mAh g−1 after 100 cycles at the current density of 0.1 A g−1. Its excellent electrochemical properties imply its high potential application for high-performance lithium-ion battery anode materials.

Urea-assisted one-step synthesis of cobalt ferrite impregnated ceramic membrane for sulfamethoxazole degradation via peroxymonosulfate activation

In this study, a novel CoFe2O4 nanocatalyst impregnated Al2O3 ceramic membrane was prepared via a urea-assisted one-step combustion method. The catalytic membrane was characterized by field emission scanning electron microscopy (FESEM) with energy dispersive X-Ray analysis (EDX) and applied for the catalytic degradation of sulfamethoxazole (SMX) via peroxymonosulfate (PMS) activation under a dead-end membrane filtration mode for the first time. Results indicate that CoFe2O4 could be impregnated into the macropores throughout the whole Al2O3 ceramic membrane via this method and the CoFe2O4 loading amount could be controlled by the multiple impregnation cycles. The membrane filtration operation mode significantly enhances the accessibility of the catalytic active sites to PMS and SMX in microreactor environment and thus the CoFe2O4 impregnated membrane displays excellent catalytic activity for the SMX degradation. The pure water permeability flux can maintain at ∼3000 L m−2 h−1 bar−1 (LMHB) with the catalyst loading amount of 0.015 g/g Al2O3. In the membrane filtration system, the removal rate of SMX with the initial concentration of 10 mg L−1 can achieve to ∼98%, 70% and 40% with the residence time of 90, 36 and 18 s. The catalytic membrane shows a great tolerance at wide pH range (3–11), the existence of humic acid and anions. Meanwhile, the membrane shows self-cleaning property by retaining >90% of initial flux after 3 treatment cycles. Electron paramagnetic resonance (EPR) and radical quenching experiments indicate that both sulfate radical and hydroxyl radical are generated and sulfate radical is the dominant active species in the process.

Synthesis and characterization of Sr2Fe1.4Ni0.1Mo0.5-xNbxO6-δ (x = 0, 0.05, 0.1, and 0.15) cathodes for solid oxide fuel cells

Nb modified Sr2Fe1.4Ni0.1Mo0.5-xNbxO6-δ (SFNi0.1MNbx, x = 0, 0.05, 0.1, and 0.15) materials are synthesized by the one-step combustion method, and their characteristics are investigated. According to the X-ray diffraction (XRD), all samples present single perovskite structures and scanning electron microscope (SEM) results indicate that all samples possess uniform porous structures. Additionally, the electrode conductivity is improved by doping Nb on the B′ site of SFNi0.1M. From the X-ray photoelectron spectroscopy (XPS) results, the ratios of Fe2+/Fe3+ and Mo6+/Mo5+ vary with the Nb content, which leads to the conductivity change of SFNi0.1MNbx materials. For all the samples, SFNi0.1MNb0.05 exhibits the best electrochemical performance with the lowest polarization resistance of 0.11 Ω cm2 and the highest power density of 1260 mW cm−2 800 °C in humidified H2. The results indicate that SFNi0.1MNbx is a promising type of candidate cathode for solid oxide fuel cells.

Luminescence in Ba2 Sr2 Al2 O7 :RE (RE=Tb(3) (+) ,Eu(3) (+) and Dy(3) (+) ) novel aluminate phosphors.

The luminescence of novel rare earth (Tb(3) (+) , Eu(3) (+) and Dy(3) (+) )-activated Ba2 Sr2 Al2 O7 phosphors for solid-state lighting is presented. The aluminate phosphors were synthesized using a one-step combustion method. X-Ray diffraction, scanning electron microscopy and photoluminescence characterizations were performed to understand the mechanism of excitation and the corresponding emission in the as-prepared phosphor, as characterized the phase purity and microstructure. Improvements in the luminescence properties of the phosphors with rare earth concentration were observed. The phosphor hue could be tuned from blue, green and red by proper selection of rare earth ions in typical concentrations. Effective absorption in the near-ultraviolet region was observed, which makes the phosphor a potential candidate for ultraviolet light-emitting diodes. Copyright © 2016 John Wiley & Sons, Ltd.

Porous bimetallic Mn2Co1Ox catalysts prepared by a one-step combustion method for the low temperature selective catalytic reduction of NOx with NH3

The porous Mn2Co1Ox catalysts are prepared by a one-step combustion (CB) method for low temperature deNOx process. This catalyst displays an excellent NH3-SCR activity, achieving 100% NOx conversion at 150–300°C. In addition, the catalyst shows high N2 selectivity, wide operating temperature window, high stability, and high H2O and SO2 resistance. The crystalline phase of CoMn2O4, porous structure and large specific surface areaare beneficial for the deNOx activity. The catalyst exists abundant Mn4+, Co3+ and surface adsorbed oxygen species, which improve the catalyst's redox ability. Plenty of acid sites from the strong interaction of manganese and cobalt oxide enhance the catalyst performance.

Study on the enhanced electrochemical performance of LiMn2O4 cathode material at 55 °C by the nano Ag-coating

In this paper, the nano-sized Ag particles were coated on the surfaces of the spinel LiMn2O4 nanoparticles through a one-step combustion method. It was shown that the rate performance and cycling performance of LiMn2O4 could be effectively improved by the appropriate amount of Ag (5wt%) not only at room temperature (25°C) but also at high temperature (55°C). This was because the Ag particles dispersed on the surface of LiMn2O4 had dramatically increased its electronic conductivity. Definitely, the electrochemical performance of the Ag-coated LiMn2O4 particles at 55°C was not as excellent as that at 25°C. Besides, the Ag-coated LiMn2O4 displayed much better cycling performance at higher C-rates (2C and 5C) at 55°C, compared with that at lower C-rate (0.5C). This was because Ag was just dispersed rather than being densely coated on the surface of LiMn2O4, so the dissolution of LiMn2O4 at 55°C could not be completely inhibited by Ag. Moreover, the dissolution of LiMn2O4 at 2C and 5C at 55°C was much weaker than that at 0.5C, caused by the faster transformation between Mn3+ and Mn4+. As a result, the electrochemical performance of LiMn2O4 could be enhanced by the Ag-coating at high temperature.

Combustion synthesis of Li8Bi2(MoO4)7 and its visible light photocatalytic properties

Li8Bi2(MoO4)7 was synthesized by a one-step combustion method. The structure, morphology, adsorbance, optical and photocatalytic properties of as-obtained sample were studied by X-ray powder diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometry. The experimental results show that the formation of tetragonal Li8Bi2(MoO4)7 was one-pot achieved. The sample exhibits a irregular particle morphology with an average size of ~0.6μm. The direct energy band gap calculated from the diffuse reflectance spectrum is 3.25eV. Compared with TiO2 (P25), as-synthesized Li8Bi2(MoO4)7 shows better visible light photodegradation performance for MB, which can be attributed to its excellent adsorbability.

Combustion synthesis of magnetic Ag/NiFe2O4 composites with enhanced visible-light photocatalytic properties

Magnetic Ag/NiFe2O4 (ANFO) photocatalysts were synthesized by a one-step combustion method. The structures, morphologies, optical, magnetic, and visible-light photocatalytic properties of as-prepared ANFOs were characterized. Experimental results showed that cubic spinel NiFe2O4 and face-centered-cubic Ag were exclusively obtained. With increasing Ag content, red shift of the absorption edge and photoluminescence quenching were observed. The magnetic properties of ANFOs ensure the magnetic separation by using a magnet. ANFO with a mole ratio of Ag to NiFe2O4 of 0.04 shows the best visible-light photodegradation performance of methylene blue, which can be ascribed to the decrease in the energy band gap and the efficient transfer of photo-generated electrons from NiFe2O4 to Ag nanoparticles. Moreover, no obvious deterioration was observed the cycle photodegradation experiments.

Combustion synthesis and photocatalytic properties of magnetically separable Zn1−xCdxS/γ-Fe2O3 composites

Magnetically separable Zn1−xCdxS/γ-Fe2O3 (x=0–1) photocatalysts were synthesized by a one-step combustion method. The structures, morphologies, absorbance, optical and photocatalytic properties of the samples were studied by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectrophotometry and photoluminescence. The experimental results show that the formation of hexagonal Zn1−xCdxS and γ-Fe2O3 and the combination of them were one-pot achieved. The Cd2+ content has a significant influence on the absorbance of visible light and fluorescence properties. The magnetic properties of samples ensure the magnetic separation by using a magnet. CdS/γ-Fe2O3 shows the best photocatalytic performance compared with other samples, ascribed to its small energy band gap and matching energy band structure between CdS and γ-Fe2O3. Moreover, no obvious deterioration was observed in the stability tests.

One-step combustion synthesis of NiFe2O4-reduced graphene oxide hybrid materials for photodegradation of methylene blue

NiFe 2 O 4-reduced graphene oxide (RGO) hybrid materials (NFRGs) were synthesized by a simple one-step combustion method. The structures, morphologies and magnetic properties were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and vibrating sample magnetometer analysis. The results show that graphene oxide sheets are not oxidized, but reduced to RGO. The superparamagnetic behavior of NFRGs was observed. The as-synthesized magnetically separable NFRGs show improved photodegradation performance when compared to neat NiFe 2 O 4, attributed to the narrowing band gap, the efficient transfer of photo-generated electron from NiFe 2 O 4 to RGO sheets, and the improved adsorptive property of photocatalyst due to the high specific surface area of RGO sheets.

One-step combustion synthesis of CoFe2O4–graphene hybrid materialsfor photodegradation of methylene blue

CoFe2O4–graphene hybrid materials (CFGHs) were synthesized by a simple one-step combustion method. The structures, morphologies and magnetic properties were characterized by X-ray diffraction, transmission electron microscopy, Raman spectrometry, vibrating sample magnetometry, and photoluminescence. The morphologies of CFGHs show that CoFe2O4 nanoparticles were anchored onto the surface of graphene sheets. After the combustion synthesis, graphene oxide sheets were not oxidized, but reduced. CFGHs exhibit ferromagnetic behaviors and can be magnetically separated. Compared with pure CoFe2O4, CFGHs show improved photodegradation performance. The mechanism of enhancement in photodegradation performance is discussed in detail.

Combustion synthesis of graphene oxide–TiO2 hybrid materials for photodegradation of methyl orange

Graphene oxide (GO)–TiO2 hybrid materials with enhanced photocatalytic properties were synthesized by a one-step combustion method using urea and titanyl nitrate as the fuel and oxidizer, respectively. During the synthesis procedure, the precursors containing GO, fuel, and oxidizer were maintained at different combustion temperatures (300–450°C) for 10min to ignite the combustion reaction. The effects of combustion temperatures on the weight loss, chemical status and photocatalytic properties were studied by thermogravimetry and differential scanning calorimetry, X-ray photoelectron spectroscopy, Raman, and photoluminescence. GO in the GO–TiO2 hybrids were not oxidized, but thermally reduced by decomposition of partial oxygen-containing groups. Meantime, the nitrogen doping of GO was achieved. Compared to the neat TiO2 obtained at same condition, GO–TiO2 hybrid obtained at 350°C exhibited enhanced photodegradation performance, which is attributed to the effective photo-generated electron transferring from TiO2 to partially reduced GO, which confirmed by the photoluminescence quenching of TiO2.

Synthesis of Carbon Nanotubes from Polypropylene in the Presence of Ni/Mo/MgO Catalysts via Combustion

Abstract We demonstrated an efficient improvement of activity of Ni catalysts by combining with Mo and Mg elements, by which massive growth of multiwalled carbon nanotubes (MWNTs) with straight and double helical structures have been achieved from polypropylene (PP) by means of a one-step combustion method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) are applied to characterize the morphology and the purity of products.