Temperature effect over structure and photochemical properties of nanostructured SnO2 powders

Abstract

We successfully synthesized tin dioxide nanoparticles with polyhedral morphology via an ethylene glycol assisted sol-gel approach. The structural characteristics of three tin dioxide samples were investigated after being thermally treated at 400°C, 600°C and 800°C. X-ray diffraction (XRD) patterns clearly show the formation of single phase tin dioxide nanoparticles, with crystallite size of 6–20 nm, in good correlation with Fourier transform infrared (FTIR) spectra. Transmission electron microscopy (TEM) analysis confirms the formation of 6nm polyhedral nanoparticles for the 400°C sample. Ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectra suggest a high concentration of oxygen vacancies. The oxygen vacancy concentration increases with temperature, due to the combined action of the formation of VO and the energetic O compensation. X-ray photoelectron spectroscopy (XPS) analysis also confirms the formation of single phase tin dioxide and the presence of oxygen vacancies in good agreement with UV-VIS and PL data.

Effects of tetrahedral molybdenum oxide species and MoOx domains on the selective oxidation of dimethyl ether under mild conditions

“…In Fig. 6, the binding energy of Mo 3d with a spinorbit doublet at 232.9 and 236.2 eV corresponding to the presence of the Mo 6+ oxidation state 28,29 decreased obviously from 573 to 673 K, then increased from 673 to 1073 K, and the binding energy of Sn 3d with a spin-orbit doublet at 486.8 and 495.5 eV confirming the presence of the Sn 4+ oxidation state 30,31 decreased from 473 to 973 K, then increased from 973 to 1073 K. The binding energy of O 1s with a peak at about 530.8 eV assigned to oxygen species 32 also decreased from 473 to 973 K, then increased from 973 to 1073 K. The decrease in binding energy of Mo 3d from 573 to 673 K can be ascribed to the MoO 3 phase transformation from the hexagonal phase to the orthorhombic phase, and the increase in binding energy from 673 to 1073 K can be attributed to the contraction of the crystalline MoO 3 structure due to the elevated calcination temperature. The decrease in binding energy of Sn 3d and O 1s from 473 to 973 K can be ascribed to the contraction 30 of the crystalline SnO 2 structure due to the elevated calcination temperature, and the increase in binding energy of Sn 3d and O 1s from 973 to 1073 K can be In Fig.…”

Characterizations of tin (SnO2) doped KIT-5 by direct synthesis

“…Similarly a band at 960 cm À1 is assigned to the SieOeH/SieOeSn stretching vibration [7,34]. On the other hand, non-framework SnO 2 species may also give the bands in the range around 670 cm À1 is due to the SneOeSn vibration [35]. Prominently, the sample Sn-KIT-5(10) showed a new band at 679 cm À1 .…”

Varying electrical and dielectric properties of Ni:SnO2 films by MWCNTs and GNPs coating

“…The low-intensity green emission bands at 531 nm are most probably originated from V O and O Sn defects. The emission in the blue-green range (bands at 423, 449, 487 and 531 nm) are defect-related emissions, generated by V O 's[60]. Carbon structure-specific peaks were not seen in the samples.…”