When we prepared nanomaterials using Hydrothermal / Wet chemical methods above 200 C temperature. Are we able to get pure phase with impurity in Powder XRD studies .
As you may know, generally nanoparticles (NPs) have problem in diffraction if their crystallite size is very less. Sometime even low volume of sample (if volume is synthetically limited) do reduce the chance of this. Hence, the impurity phase identification largely depends on the crystallite size of phases present in your NP sample. If it is single phase and its crystallite size is large enough to diffract, 'YES'. You will be able to identify through PXRD. Suppose if you have more than one phase, yet you may get to know about it, provided the impurity phases are too diffracting significantly. In other words, in a multi-phase sample, if any of the phases present is (x-ray) amorphous then you will not be able to identify that phase. Hope you got the point.
Your question is not clear. A pure phase is certainly obtainable with hydrothermal method, you can change a lot of parameters, such as the temperature, the concentration, the solvent and so on. XRD is a means you can use to verify if your synthesis was successful
Extreme sorry correction in my question to Honorable viewer, Hydrothermal / Wet chemical methods above 200 C temperature. Most of the paper shown that nanocrystals phase with impurities in Powder XRD studies. Ex: Synthesis of TiO2 give Anatase phase majorly with trace amount of impurity like (Rutile or brookite).
To Dr. Marcella, How to control impurity using temperature mode.
To Sunil kumar, Is there any limitation in certain nano material size for purity
You can try to change the temperature in the hydrothermal reactor and collect XRD patterns to see if anything changes. In many cases also a dilution of the solution can allow some improvements (positive or negative, it depends..). A pure anatase could be difficult to synthesize
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