Facile-Controlled Epitaxial Growth Direction of Heterogeneous Core/Shell Structured NaLnF4 Nanocrystals through Traditional Methods
1
Citation
32
Reference
10
Related Paper
Citation Trend
Abstract:
Fabrication of nanoscale materials with desirable morphology and surface properties becomes more urgent when constructing hybrid nanocrystals with multiple functionalities. Here, we report a facile measure to control the outer layer growth direction combining with coprecipitation and thermal decomposition method for constructing a series of heterogeneous core/shell structured NaLnF 4 nanocrystals, involving NaYF 4 and NaNdF 4 material. Our investigations suggest that it is feasible to control over the outer layer growth orientation by combining the two traditional methods.Keywords:
Coprecipitation
Coprecipitation
Layered double hydroxides
Cite
Citations (6)
Cu-Mn/ZrO 2 catalysts have been prepare by oxalate gel coprecipitation as well as Na 2CO 3 coprecipitation methods, and the catalysts obtained behave remarkably different activity and selectivity for CO hydrogenation to methanols ynthesis. The catalysts prepared by oxalate gel coprecipitation perform a higher activity, its surface area and particle size are lower than those of Na 2CO 3 coprecipitation prepared catalysts. The XRD patterns exhibit a kind of complex oxide that only exists in Na 2CO 3 coprecipitation prepared catalysts. The interaction among Cu,Mn and Zr is thought to be important in the characteristics of catalysts.
Coprecipitation
Cite
Citations (0)
Coprecipitation
Cite
Citations (72)
Coprecipitation
Cite
Citations (12)
Abstract Coprecipitation is one of the classical, but quite useful, techniques for separation/preconcentration for trace element analysis. Many elements can be easily collected with a carrier precipitate, and the handling is simpler and easier compared to that of other techniques such as solvent extraction and solid‐phase extraction. In addition, selective separation can also be designed by controlling of chemical and physical conditions in the procedure. In this section, mechanisms of coprecipitation, selection of a carrier precipitates, selectivity in coprecipitation, and typical examples of coprecipitation in trace element analysis are described.
Coprecipitation
TRACE (psycholinguistics)
Trace element
Cite
Citations (5)
In this paper the coprecipitation was improved(called spraying coprecipitation)to pre-pare nano gas sensitive materials such as ZnGa 2 O 4 and ZnFe 2 O 4 .The structural analysis was done by XRD,SEM and TEM.The result shows that the size and the uniform of the material pre-pared by the spraying coprecipitation is better than ever.Transport and reaction process of spray-ing coprecipitation was analysed by hydrodynamics theory.Some experiments were explained.The principle of spraying coprecipitation was also discussed.
Coprecipitation
Cite
Citations (0)
Coprecipitation is the method most frequently applied to prepare Layered Double Hydroxides (LDHs). Two variations of this method can be used, depending on the pH control conditions during the precipitation step. In one case the pH values are allowed to vary while in the other they are kept constant throughout coprecipitation. Although research groups have their preferences, no systematic comparison of the two variations of the coprecipitation method is available in the literature. On this basis, the objective of the present study was to compare the properties of LDHs prepared using the two forms of pH control in the coprecipitation method. The results showed that even though coprecipitation is easier to perform under conditions of variable pH values, materials with more interesting properties, from the point of view of technological applications, are obtained at constant pH. Higher crystallinity, smaller particle size, higher specific surface area and higher average pore diameter were found for materials obtained by coprecipitation at constant pH, when compared to the materials obtained at variable pH.
Coprecipitation
Layered double hydroxides
Cite
Citations (105)
The thermodynamic analysis on the system of Fe(Ⅱ)-Mn(Ⅱ)-Zn(Ⅱ)-CO32--NH3-H2O is carried out. The relationship between pH value and the total concentrations of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) is obtained, and the field of coprecipitation of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) is obtained at a suitable pH value. The results show that the field of coprecipitation is included in the field of precipitation of Zn(Ⅱ), while the field of precipitation of Zn(Ⅱ) is determined by the reciprocal ship of [N]T and [C]T. Furthermore the field of precipitation of Fe(Ⅱ) is related with [C]T only. Confirming the coprecipitation of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) it has important significance to prepare Mn-Zn soft magnetic ferrite ultrafine.
Coprecipitation
Cite
Citations (0)
ZnGa2O4 nano crystals were prepared by an improved coprecipitation method, which we call ‘spray coprecipitation’. XRD results shows the resulting crystal size using the new method is under 10nm, whereas the powder prepared by ordinary coprecipitation is about 30nm. XRD results also shows ZnO peaks exists in ZnGa2O4 powder prepared by traditional coprecipitation, but disappears in ZnGa2O4 nano crystal prepared by spraying coprecipitation. SEM and TEM were used to analysis the structural characteristics of ZnGa2O4 nano crystals. The gas sensitive characteristics of ZnGa2O4 nano crystals are reported.
Coprecipitation
Cite
Citations (36)
The chemical coprecipitation process for synthesizing BaCoTiFe_(10)O_(19) ultrafine powders has been investigated by means of corrosion versus pH plot (E-pH plot) for metal element, thermodynamic calculation and co-dump coprecipitation experimentation. The results show that the theoretical pH values of complete coprecipitation of all Fe~(3+), Ti~(4+), Co~(2+) and Ba~(2+) cations were in 9≤pH≤12.2 obtained by E-pH plot and pH≥7.9 obtained by thermodynamic calculation, respectively. The co-dump coprecipitation experiments indicate that the minimum pH value necessary to the formation of single-phase BaCoTiFe_(10)O_(19) under 900℃ for 2h was pH=8.5. It was suggested that three different results and their dependency originate from both synergetic coprecipitation effect of cations and coordination effect of Cl~- anions.
Coprecipitation
Barium
Cite
Citations (1)