Search results

Introduction Coating deposition on the different surfaces allows us to solve a number of important technological problems.
The data base JCPDS was used for diffractograms interpretation.
The relative intensities of the diffraction reflections of textured material were determined according to ASTM card file.

Diameter (nm) Number (%) Fig.1.
Fig. 3a shows the X-ray diffraction pattern of non-doped sample after calcinations at 1000°C during 1 h, the powders show a monophased structure and the Miller indices (hkl) can be assigned to the a-Al2O3 phase in good agreement with JCPDS data card No 10-173.

The patterns in Fig. 2 display characteristic diffraction peaks consistent with the hexagonal wurzite structure of ZnO (JCPDS card no. 36-1451) and the tetragonal rutile structure of SnO2 (JCPDS card no. 41-1445) at various doping concentrations [24, 28].
The likely reasons are that excessive Sn leads to defect clustering or secondary phase formation, reduces the number of available adsorption sites, and increases charge-carrier recombination due to trap states [34].

The cycling stability test was conducted at a constant current density of 1 A/g, ensuring a consistent and reliable assessment of the material's performance over an extended number of cycles.
Specifically, the peaks at 26.5°, 33.9°, and 52.0° are indexed to the (110), (101), and (211) crystal planes of SnO2 (JCPDS Card No. 41-1445), respectively.
Meanwhile, the peaks at 22.5°, 37.9°, 41.2°, 62.7°, and 65.5° are assigned to the (200), (211), (421), (511), and (002) crystal planes of MnO2 (JCPDS Card No. 44-0141), respectively.

However, it could be seen a large number of ZnO agglomerative nanoparticles.
It could be seen from fig. 3 that all the diffraction peaks can be indexed as the hexagonal ZnO, consistent with the values in the standard card (JCPDS 36-1451).

The highlight areas may be caused by the segregation of Y and Nb, which have larger atomic numbers.
From the XRD patterns, we can see that there is only main crystal phase YNbTiO6 and its peaks coincide completely with the datum on the JCPDS card: 14-0643.

Though a number of efficient methods have been developed for the synthesis of Fe3O4 nanoparticles including hydrothermal synthesis[8], sol-gel method[9], co-precipitation process[9,10], microwave hydrothermal method[11], pyrolysis process[12], co-precipitation process was selected to be synthesis technology of Fe3O4 nanoparticles in this study because it allows lower processing temperature, simple procedure and simple equipment[13].
Both diffraction peaks corresponding to Fe3O4 have been observed, indexed to (220), (311), (400), (333) and (440) planes of a cubic unit cell (JCPDS card no. 79-0418).

Infrared spectra were recorded via a Fourier Transform infrared spectrometer (TENSOR 37, Bruker, Germany) in a wave number range from 400 to 4,000 cm-1.
The diffraction peaks coincide well with the standard pattern of body-centered cubic Y2O3 crystal structure (JCPDS Card No.70-0603).

The XRD pattern (Fig.1) shows that all the diffraction peaks of the product could be readily indexed to hexagonal phase of NaYF4 with lattice constants of a=b=0.596nm, c=0.353nm, JCPDS card No. 16-0334.
The analysis of a number of the products shows that these microsheets have an average diameter of 6.25 μm and a thickness of 90nm.

The diffraction patterns were analyzed and compared with standard Joint Committee on Powder Diffraction Standards (JCPDS) files to confirm phase purity and crystallinity.
The XRD pattern of the commercial aluminum oxide (Al₂O₃) catalyst showed sharp and well-defined peaks at 2θ values of 25.55°, 34.86°, 38.08°, 42.44°, 52.00°, and 59.83°, indicating a crystalline structure and matching the database of the Joint Committee on Powder Diffraction Standards (JCPDS) card file No. 46–1215.
These assignments match well with standard reference patterns (e.g., JCPDS Card No. 37-1497), confirming the presence of pure crystalline CaO without major impurity phases.
This morphology is beneficial for catalytic applications as it implies a higher surface-to-volume ratio, which can enhance the number of available active sites during processes like biomass pyrolysis and bio-oil upgrading [13] .
A number of researches have previously investigated the structural, chemical, and thermal properties of calcium oxide (CaO) and aluminum oxide (Al2O₃) as catalysts for biomass pyrolysis.