- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Cost-efficient solar cells using nanocrystalline perovskite La (Fe and Mn) O3 and candle soot: Theory and experiment
摘要： In present investigation, co-precipitation as a simple, low temperature synthesis and low cost route was used to prepare nanocrystal perovskite La (Fe and Mn) O3 for solar cell application. The synthesized powders were characterized by XRD, SEM, PL, DRS, CV, EDS, and FTIR analysis. The photovoltaic behavior of prepared La (Fe and Mn) O3 perovskite as photo anode was also investigated, experimentally and theoretically. The best power conversion efficiency was experimentally obtained by LaFeO3 perovskite (0.07). Two different counter electrodes were applied: Pt electrode and an electrode prepared from a candle soot coated on the surface of FTO glass as a remarkable alternative material and process of noble metal electrode (Au or Ag) deposited by complicated vacuum technologies. In another stage, commercial electrolyte was used to enhance efficiency. These results indicate that there is a possibility to further increase the performance and efficiency of perovskite based cells.
关键词： Candle soot,Solar cell,Perovskite,Co-precipitation
更新于2025-09-11 14:15:04
-
Harmonic mode-locking in an external cavity tapered diode laser with saw-toothed microstructure
摘要： As a widely used approach to modify a material’s bulk properties, doping can effectively improve electrochemical properties and structural stability of various cathodes for rechargeable batteries, which usually empirically favors a uniform distribution of dopants. It is reported that dopant aggregation effectively boosts the cyclability of a Mg-doped P2-type layered cathode (Na0.67Ni0.33Mn0.67O2). Experimental characterization and calculation consistently reveal that randomly distributed Mg dopants tend to segregate into the Na-layer during high-voltage cycling, leading to the formation of high-density precipitates. Intriguingly, such Mg-enriched precipitates, acting as 3D network pillars, can further enhance a material’s mechanical strength, suppress cracking, and consequently benefit cyclability. This work not only deepens the understanding on dopant evolution but also offers a conceptually new approach by utilizing precipitation strengthening design to counter cracking related degradation and improve high-voltage cyclability of layered cathodes.
关键词： doping,precipitation strengthening,TEM,layered cathodes
更新于2025-09-11 14:15:04
-
7.4: Metal Halide Perovskite Nanophosphors for Micro‐LEDs
摘要： 1. Changes in precipitation have the potential to cause dramatic changes in ecosystem carbon (C) cycling; however, it remains unclear whether different components of the net ecosystem exchange (NEE) (e.g., C uptake vs. release, plant vs. microbe respiration, above-ground vs. below-ground plant respiration) have similar or differential sensitivity to precipitation gradients. 2. We conducted a manipulative field experiment (from 2015 to 2017) with six precipitation treatments, including 1/12 annual precipitation (P), 1/4 P, 1/2 P, 3/4 P, P and 5/4 P in an alpine meadow to investigate the responses of the NEE components. 3. Over the 3 years, all C fluxes showed a nonlinear response to the precipitation gradients, except for root respiration. The most extreme drought treatment (1/12 P) caused strong reductions in NEE by 15.57%, gross primary productivity by 17.26% and ecosystem respiration by 19.05%, in contrast to the control. Plant respiration was more sensitive to precipitation change than microbe respiration, and above-ground plant respiration was more susceptible than below-ground respiration. Structural equation models revealed that the response of C fluxes under precipitation changes was primarily due to changes in the soil water content and above-ground net primary productivity. 4. Our findings indicate that future precipitation changes, particularly extreme drought, will decrease ecosystem C fluxes with different magnitudes, leading to a consequent reduction of NEE. These emergent ecosystem properties are essential for the improved elucidation of carbon cycle dynamics and benchmarking models, to predict ecosystem responses to precipitation changes.
关键词： carbon fluxes,manipulative experiment,precipitation gradient,climate extremes,alpine meadow,nonlinear response
更新于2025-09-11 14:15:04
-
Enhanced sunlight photocatalytic degradation of methylene blue by rod-like ZnO-SiO2 nanocomposite
摘要： This work aims to develop a novel and economical rod-like zinc oxide–silicon dioxide (ZS) nanocomposite by a simple co-precipitation method with different surfactants, such as cationic surfactant cetyl triethylammonium bromide (CTAB), non-ionic polymer polyvinyl pyrrolidone (PVP), and an anionic surfactant sodium dodecyl sulfate (SDS). The phase identification, surface topography and optical properties were analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), UV-Visible and Photoluminescence Spectroscopy. The photocatalytic degradation efficiency of the prepared nanocomposite was measured using model organic pollutant of methylene blue (MB) in water under sun light irradiation. Due to surface plasmon resonance (SPR) effect of SiO2 nanoparticles, ZS nanocomposite shows an absorption peak (434 nm) in the visible region. Hence the maximal MB degradation efficiency of 97.8% was achieved under 90 min of sunlight irradiation. Among the three surface-active agents, cationic surfactant shows the highest degradation ability with ZS nanocomposite. This work will open a new platform for further development of ZS-based nanocomposites to solve the global photocatalytic and waste water treatment problem.
关键词： ZnO–SiO2,Co-precipitation,Sun light,Surfactant,Methylene blue
更新于2025-09-11 14:15:04
-
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
-
Observation of Longitudinal Spin Seebeck Voltage in YIG Films Chemically Prepared by Co-Precipitation and Spin Coating
摘要： Longitudinal spin Seebeck effect (LSSE) of Y3Fe5O12 (YIG) thin films chemically prepared on a Si substrate with a SiO2 surface layer has been investigated with a particular focus on its dependence on the metal (Pt or W) for the capping layer used to carry out the measurements. The YIG films are prepared by a combination of co-precipitation, spin coating, and annealing processes. The structural characterization by X-ray diffraction proves that the films are polycrystalline in a garnet phase with an average crystallite size of ～34 nm. The microstructural analyses of the film surface by scanning electron microscopy and scanning probe microscopy show that the roughness Ra of the film is ～31 nm. The magnetic easy axis of the YIG films is in the direction parallel to the films. We have found that the polarity of the LSSE voltage VLSSE measured with a Pt capping layer apparently differs from that observed when a W capping layer is used. The value of VLSSE increases almost linearly with increasing temperature difference (cid:2)T independent of the choice of metal for the capping layer. The observed LSSE for the polycrystalline YIG films is one order of magnitude smaller than that reported for YIG and Bi:YIG single-crystal samples grown by metal–organic decomposition.
关键词： Co-precipitation,spin coating,garnet ferrite,spin Seebeck effect (SSE)
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
-
Effect of calcium oxide doping on the microstructure and optical properties of YAG transparent ceramics
摘要： Yttrium aluminium garnet (YAG, Y3Al5O12) transparent ceramics were fabricated by vacuum sintering the co-precipitated raw powders with calcium oxide (CaO) as the sintering aid. The influence of CaO content on the phase composition, particle size and the morphologies of resultant YAG powders, as well as the microstructural and optical properties of YAG ceramics, was investigated in detail. Our results show that with increasing of CaO additives, the particle size and agglomeration degree of the powders were slightly increased and the grain growth of the ceramics was inhibited. Specifically, the grain size initially decreased dramatically till reaching a minimum value of 1.85 μm with 0.3 at% CaO, then slightly increased. In addition, for YAG ceramics with a high CaO doping level, the existence of liquid phase was observed for the first time and its sintering mechanism was discussed. The excess of CaO causes the formation of grain boundary phases and residual pores, which are detrimental for maintaining higher optical quality of YAG ceramics. We obtained a fully dense and pore-free YAG ceramic with an in-line transmittance of 80.8% at 1100 nm by adopting 0.1 at% level of CaO during sintering of the green bodies at 1780°C for 20 h in vacuum.
关键词： Microstructure evolution,YAG transparent ceramic,Co-precipitation method,CaO additives
更新于2025-09-10 09:29:36