Chemical assist rapid sonochemical synthesis of Cr doped SnO₂ nanoparticles for the hydrogen gas sensing application

An effective chemical assist Sonochemical method was used to synthesize facile and homogenous undoped and Cr (3, and 6 at. %) doped SnO2 nanoparticles within aqueous solution. Different characterization methods, including X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), UV-vis spectroscopy Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy and gas sensing were used to examine the structural, optical and chemical behavior of the synthesized SnO2 nano-particles. The XRD results showed that the synthesized SnO2 nanoparticles exhibit high crystallinity and rutile phase. The synthesized SnO2 nanoparticles had an average crystallite size of 7.8 +/- 2 nm. Crystallite size is found to be decreased when chromium is doped in SnO2 at different concentrations.The morphology of SnO2 nanoparticles was studied by FESEM, and the results showed that the developed SnO2 nanoparticles are uniform, spherical, and evenly dispersed. The SnO2 nanoparticles were investigated by EDS's chemical technique. The chromium, oxygen peak and Sn peak are present, according to the EDS spectra. The doping concentrations of Cr (3 % and 6% wt.) confirmed from the EDS spectrum. The Optical band gap of Undoped and Cr doped SnO2 nanoparticles were evaluated by UV-Vis Spectroscopy. The results demonstrated that band gap of the SnO2 nanoparticles increased with addition of the Cr contents. Fourier Transform Infrared Spectroscopy was used to analyze the chemical characteristics of SnO2 nanoparticles. The Sn-O band stretching was confirmed from the FT-IR investigation. Further, the rutile tetragonal phase confirmed the A1g vibration mode of the Rutile SnO2 symmetry from Raman spectroscopy. Finally, the gas sensing characteristics of the SnO2 nanoparticles were studied at 270 degrees C the resistances versus ambient gas time. It has been observed that sensi-tivity of the prepared sample was higher than reported in the literature.