- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Saponification Precipitation Method of CsPbBr3 Nanocrystals with Blue-Green Tunable Emission
摘要： We report on a new synthesis process for halide perovskite nanoplatelets and nanoplates that switches the production process of the cesium precursor from a fatty acid/cesium salt reaction to a cesium base/fatty acid ester reaction, thus enabling the reaction to occur in ambient conditions in minutes instead of hours. The saponification precipitation process reported here, as a result, does not require a vacuum oven or inert reaction environment in obtaining the cesium precursor, or any part of the reaction. Furthermore, the process creates a hygroscopic byproduct that results in a self-drying synthesis. The obtained perovskite nanocrystals exhibit a blue-green tunable emission that occurs via quantum confinement effect, phase, and morphology change. The consequence of these physical processes is that the band gap is highly tunable with temperature and the resulting nanocrystals show remarkable optical properties, while greatly simplifying the production of halide perovskite nanoplatelets and nanoplates.
关键词： Blue-Green Tunable Emission,Saponification Precipitation Method,Hybrid Materials,Magnetic,CsPbBr3 Nanocrystals,Plasmonics,Optical
更新于2025-11-19 16:46:39
-
Interesting makeover of strontium hexaferrites for environment remediation from excellent photocatalysts to outstanding adsorbents via inclusion of Mn3+ into the lattice
摘要： Manganese incorporated strontium hexaferrites with composition SrMnxFe12-xO19 (x= 0.0, 0.4, 0.8, 1.2, 1.6, 2.0, 3.0, 4.0 and 5.0) were fabricated via chemical co-precipitation methodology. Various characterization techniques were employed to investigate the physical properties of the synthesized hexaferrites. Powder X-Ray Diffraction (XRD) patterns revealed the formation of hexagonal phase with P63/mmc space group. FE-SEM micrographs exhibited hexagonal morphology of the synthesized materials; particle size of 125-150 nm range was observed. EDX spectra unveiled the presence of desired elements. The lattice interplanar fringe width from HR-TEM images was observed to be 0.22 nm, 0.26 nm and 0.27 nm indexed to (114), (107) and (203) planes of the manganese doped strontium hexaferrite. Surface area of the synthesized hexaferrites was found to be in the range of ~7.8 to ~8.4 m2/g, scrutinized by Brunauer–Emmet–Teller (BET) plots. Saturation magnetisation values were found to decrease with increase in Mn content from 38.7 to 11.7 emu/g, albeit retaining sufficient magnetic strength to be recovered using an external magnet. Absorption edge for all the hexaferrites was found to lie in the visible region of the spectrum. The oxidation state of different elements present in synthesized hexaferrites was scrutinized using X- ray Photoelectron Spectroscopy (XPS). To explore the catalytic efficiency of the synthesized hexaferrites, photo-fenton degradation of methyl orange (MO), remazol deep red (RDR) and p-nitrophenol (PNP) was employed. All the synthesized hexaferrites were found to be highly proficient, degrading the pollutants upto ~98%. Interestingly, astonishing adsorption of ~92.7 % was showcased by SrMn5Fe7O19, prior to the addition of oxidizing agent indicating the symptomatic transformation from excellent photocatalyst to outstanding adsorbents via incorporation of Mn3+ into the lattice. The maximum adsorption capacity of 56.20 and 112.35 mg/g was observed for MO and RDR, respectively.
关键词： photo-fenton degradation,strontium hexaferrites,adsorption,chemical co-precipitation method,manganese substituted ferrites
更新于2025-11-14 17:03:37
-
Graphene oxide-based zirconium oxide nanocomposite for enhanced visible light-driven photocatalytic activity
摘要： In the present investigation, an efficient visible light-active, graphene oxide-based zirconium oxide nanocomposite (GO–ZrO2) has been synthesized by co-precipitation method. The synthesized photocatalyst was characterized by XRD, FTIR, FE-SEM, EDS, TEM, TGA, PL, UV-DRS and BET surface area analysis. The characterization results illustrate the homogeneous dispersion of ZrO2 nanoparticles in the GO–ZrO2 nanocomposite with excellent harmony between GO and ZrO2 nanoparticles. The photocatalytic efficiency of the synthesized GO–ZrO2 nanocomposite was evaluated by photodegradation of hazardous, water-soluble rhodamine B and methylene blue dyes under visible light irradiation. The 90% photocatalytic degradation of rhodamine B dye (with initial conc. 30 mg/L) was observed in 105 min of visible light irradiation, while 99.23% of methylene blue (with initial conc. 100 mg/L) dyes degradation was observed in just 60 min using 25 mg/100 ml dose of GO–ZrO2 nanocomposite as a photocatalyst. The mechanistic investigation using scavengers suggest that the superoxide (O2·?) is the most reactive species involved in the photodegradation of organic dyes. The synthesized photocatalyst GO–ZrO2 nanocomposite also exhibits excellent thermal stability and reusability.
关键词： Methylene blue,Rhodamine B,Photocatalytic activity,Zirconium oxide,Graphene oxide,Visible light,Co-precipitation method
更新于2025-09-23 15:23:52
-
Cu(OH)2 Nanostructures for Dynamic Photodegradation of Methyl Orange under Visible Light
摘要： A new material of Cu(OH)2 nanostructures was prepared using cupric nitrate and sodium hydroxide as raw materials by the chemical precipitation method. The Cu(OH)2 nanostructures were characterized by scanning electron microscope, transmission electron microscopy, infrared spectrometer, and X-ray diffractometer. The results showed that the Cu(OH)2 nanostructures exhibited excellent uniform and dispersion at 40°C. A series of factors was investigated to effect the photocatalytic efficiency of methyl orange (MO), such as the concentration of Cu(OH)2 nanostructures, the reaction time of the Cu(OH)2 nanostructures, the initial concentration of MO, and so on. As a result, the Cu(OH)2 nanostructures exhibited excellent photocatalytic efficiency with the concentration of 20 mg L–1 Cu(OH)2 nanostructures, the initial concentration of MO was 15 mg L–1 and the stirring time was 70 min.
关键词： photocatalytic efficiency,chemical precipitation method,Cu(OH)2 nanostructures
更新于2025-09-23 15:22:29
-
Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder
摘要： Yttrium aluminum garnet (YAG) materials have a number of unique properties, such that its application is extensive. In this study, ultrafine YAG powder materials were prepared by coprecipitation and hydrothermal precipitation methods. The influence of the synthesis process on the morphology of the powder was investigated. Results showed that the precursor powder prepared via the coprecipitation method mainly undergoes amorphous to crystalline transition with the increase in calcination temperature and that the precursor agglomeration is severe. In the process of increasing the calcination temperature, the dispersibility of the roasted powder is considerably improved, which is favorable for the growth of the crystal grains, such that the particle size of the powder is gradually increased. The YAG precursor prepared by the coprecipitation method is transformed into YAG crystals, with the phase transition mainly occurring between 900 °C and 1,100 °C. When the molar ratio of salt to alkali is Y3+/OH?=1:8 via the hydrothermal reaction, YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt to alkali is continuously increased, the morphology of YAG particles is not obviously changed. The coprecipitation method is used to control the particle size, whereas the hydrothermal method is used to control the particle morphology.
关键词： co-precipitation method,hydrothermal precipitation method,ultra-fine powder,YAG
更新于2025-09-23 15:21:01
-
Highly stable CdTe quantum dots hosted in gypsum <i>via</i> a flocculation–precipitation method
摘要： Poor stability hinders the practical application of aqueous CdTe quantum dots (QDs) in optoelectronic devices. In this work, a flocculation–precipitation method is demonstrated to host aqueous CdTe QDs in gypsum to form CdTe–gypsum nanocomposites, which is simple, effective and environmental-friendly. Ascribed to gypsum acting as a tight and robust matrix protection agent, the photo-, thermal-, anti-acid and long-term stability of CdTe QDs were remarkably improved. Moreover, this approach solved the problem of incompatibility between aqueous QDs and epoxy resin, allowing for the application of aqueous QDs in white light emitting diodes (WLEDs), based on which a WLED with the red-emission nanocomposites used as a color-conversion layer was successfully fabricated. These results indicate the potential of this technique in stabilizing aqueous QDs as well as their practical application in optoelectronic devices.
关键词： optoelectronic devices,stability,flocculation–precipitation method,CdTe quantum dots,gypsum
更新于2025-09-16 10:30:52
-
Submicron barium calcium zirconium titanate ceramic for energy storage synthesised via the co-precipitation method
摘要： Monodisperse submicron barium calcium zirconium titanate [(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3] powders with homogeneous spherical microstructure were synthesised via the co-precipitation method. The (Ba+Ca)/(Zr+Ti) molar ratio and concentrations of reactants and NaOH used in the synthesis process were adjusted to obtain a single phase. Thermogravimetric analysis, X-ray diffraction, infrared and Raman spectroscopies and transmission electron microscopy were used to analyse the phase formation temperature, crystalline structure and reaction mechanism of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 formation at room temperature. The results suggested that the pure perovskite phase formation temperature was approximately 900–950 °C, which is considerably lower than that of BCZT powders synthesised using the conventional solid-state reaction (1250 °C). The dense phase-pure ceramics synthesised at 1320 °C displayed high recoverable energy storage performance (0.25 J/cm3) and breakthrough field (100 kV/cm). This work provides a new strategy to lower the synthesis temperature and improve the electrical properties of perovskites as well as revealing a possible formation mechanism.
关键词： Mechanism,Energy storage,Submicron BCZT powders,Co-precipitation method
更新于2025-09-11 14:15:04
-
Effect of the Calcination Temperature on the Properties of Y-TZP Powders Prepared by Co-Precipitation
摘要： Yttria-stabilized tetragonal zirconia (Y-TZP) powders were prepared by co-precipitation, and the effect of the calcination temperature on the powder characteristics and sintering of Y-TZP ceramics was examined. Amorphous zirconium and yttrium hydroxide particles were precipitated starting from ZrOCl2·8H2O and Y(NO3)3·6H2O. After microwave drying and attrition milling, the co-precipitated gel was calcined for 1 h at different temperatures ranging from 550°C to 1050°C to obtain the tetragonal phase and remove chloride ions followed by additional milling by attrition milling for 12 h to control the size of the particles and agglomerates. The agglomeration behavior and the phase composition of the Y-TZP powders synthesized depend significantly on the calcination temperature. Powders calcined below 650°C exhibited hard agglomerates with small primary particles, which resulted in large primary and secondary agglomerates. Powders calcined above 950°C showed hard agglomerates with large primary particles and agglomerates. On the contrary, powder calcined at 850°C had soft agglomeration with small primary and secondary agglomerates; these powders had the maximum specific surface area and a good powder activity.
关键词： Co-Precipitation Method,Agglomerates,Yttria-Stabilized Zirconia,Calcined Temperature
更新于2025-09-11 14:15:04
-
Synthesis, Characterization and Electrical Conductivity of Nano-Crystalline Erbium Sesquioxide by the Precipitation Method and Subsequent Calcination
摘要： Due to its superior properties, erbium sesquioxide, Er2O3, is considered as an important material for applications in various fields such as corrosion-resistant coating, electrical insulating coating, in sensing membranes, semiconductor devices, as catalyst, and for applications in nuclear engineering. In the open literature there is a lack of information about the preparation of Er2O3 nanoparticles using the homogenous precipitation and subsequent calcination route. In this paper a facile method for the synthesis of Er2O3 nanoparticles is suggested. The fabrication was carried out by using the homogeneous precipitation of an erbium ions using sodium hydroxide followed by the calcination process. The influence of: (i) the pH value (9-12) during precipitation process, and (ii) the calcination temperature 300-700 °C on the structural and textural properties of the solids obtained will be addressed. The thermal events accompanying the heat treatment of the dried parent was monitored using thermogravimetric analysis (TGA). Various physicochemical techniques were used for investigating the structure and morphology of Er2O3 nanoparticles. These include X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, filed emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Moreover, the electrical conductivity of the calcined samples with temperature was measured.
关键词： precipitation method,nanocrystalline erbium oxide,Er2O3,electrical conductivity,erbium sesquioxide,Er2O3 nanoparticles
更新于2025-09-11 14:15:04
-
Carbon Dioxide Precipitation Method to Prepare Zinc Oxide
摘要： Carbon dioxide (CO2) was firstly used to precipitate Zn ions with urea to prepare zinc oxide (ZnO). The advantages of this method were small particle size, high yield and low sensitivity to conditions, such as temperature and time, and the decrease of solvent consumption. Further, the influence of carbon dioxide pressure, reaction time and temperature were studied and optimized.
关键词： Particle Size,Nanoparticles,Solvent Effects,Carbon Dioxide Utilization,Precipitation Method
更新于2025-09-10 09:29:36