Influence of Mn doping on structural, optical and acetone gas sensing properties of SnO2 nanoparticles by a novel microwave technique

Abstract

In the present work we have successfully synthesized pristine and manganese (Mn) doped SnO2 nanoparticles by using simple microwave irradiation technique for the first time. Powder X-ray diffraction results confirms that both the pure and doped SnO2 in tetragonal rutile type structure. Transmission electron microscopy studies illustrate that both the undoped and Mn doped SnO2 crystallites form in spherical shapes with an average diameter of 35–19 nm, which is in good agreement with the average crystallite sizes calculated by Scherrer’s formula. A considerable red shift in the absorbing band edge was observed with increasing of Mn content (0–10 wt%) by using UV–Vis diffuse reflectance spectroscopy . Oxygen-vacancies, tin interstitial and structural defects were analyzed using photoluminescence spectroscopy. The functional groups were analyzed by using Fourier transform infrared spectra. Acetone gas sensing measurement of pure and Mn-doped (10 wt%) SnO2 nanoparticles were experimented at ambient temperature using optical fiber based on clad modified method. By modifying the clad exposure to acetone vapor, the sensitivities were estimated to be 53 and 78 counts/100 ppm for undoped and Mn-doped SnO2 nanoparticles, respectively. These results show that the Mn doping into SnO2 enhances acetone gas sensing properties.