F.I. Shaikh

Enhanced acetone sensing performance of nanostructured Sm2O3 doped SnO2 thick films

Abstract In the present work, we synthesized Sm 2 O 3 doped SnO 2 in order to prepare a selective acetone sensor with fast response, quick recovery and good repeatability. Pure as well as 2 mol.%, 4 mol.%, 6 mol.% and 8 mol.% Sm 2 O 3 doped SnO 2 nanostructured samples were synthesized by using a co-precipitation method. The characterization of the samples was done by thermogravimetric and differential thermo-gravimetric analysis (TG-DTA), X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), energy dispersive analysis by X-rays (EDAX), high resolution scanning electron microscopy (HR-TEM), selected area X-ray diffraction (SAED), Brunauer-Emmet-Teller (BET) and ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy techniques. The gas response studies of liquid petroleum gas, ammonia, ethanol and acetone vapor were carried out. The results showed that Sm doping systematically lowered operating temperature and enhanced the gas response and selectivity for acetone. The response and recovery time for 6 mol.% Sm 2 O 3 doped SnO 2 thick film at the operating temperature of 250 °C were 15 and 24 s, respectively.

Synthesis and enhanced ethanol sensing performance of nanostructured Sr doped SnO2 thick film sensor

In the present paper we have synthesized pristine and Sr doped SnO2 in order to prepare a selective ethanol sensor with rapid response–recovery time and good repeatability. Pristine as well as Sr (2, 4 and 6xa0mol%) doped SnO2 nanostructured powder was synthesized by using a facile co-precipitation method. The samples were characterized by TG–DTA, XRD, HR-TEM, SAED, FEG-SEM, SEM–EDAX, XPS, UV–Vis and FTIR spectroscopy techniques. The gas response performance of sensor towards ethanol, acetone, liquid petroleum gas and ammonia has been carried out. The results demonstrate that Sr doping in SnO2 systematically decreases crystallite size, increases the porosity and hence enhances the gas response properties of pristine SnO2 viz. lower operating temperature, higher ethanol response and better selectivity towards ethanol. The response and recovery time for 4xa0mol% Sr doped SnO2 thick film sensor at the operating temperature of 300xa0°C were 2 and 7xa0s, respectively.

Synthesis, structural and optical properties of Fe-doped nanocrystalline SnO2

In the present study we have fabricated Fe doped SnO2 nanoparticles co-precipitation method. These samples were characterized by thermal gravimetric and differential thermal analysis, X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), energy dispersive studies by X-rays technique, transmission electron microscopy,selected area electron diffraction studies, Ultraviolet–Visible spectroscopy, fourier transform infrared (FTIR) spectroscopy, Raman and photoluminescence (PL) spectroscopicmeasurements. XRD analysis revealed the single phase rutile tetragonal structure of all samples. These results werefurther confirmed by Raman and FTIR studies. Crystallite size was observed to vary from 17 to 8xa0nm as the Fe content increased from 0 to 4xa0mol%, suggesting the prevention of crystal growth with Fe doping. It was evident from the absorption spectra that the absorbance increases with the dopant concentration. Optical band gap was estimated by using Tauc relation whichdecreases with the increase in Fe content confirmingthe size reduction as a result of Fe doping. Raman spectroscopic measurementsshowed thatthe broadening of intense peak observed at 630xa0cm−1 with Fe doping, indicating that the Fe ions are substituted at the Sn sites in SnO2 lattice. Room temperature PL spectra revealed that luminescent emission intensity increases with Fe concentration.

Structural, Optical and Ethanol Sensing Properties of Dy-Doped SnO 2 Nanoparticles

AbstractWe report a facile co-precipitation synthesis of dysprosium (Dy3+) doped tin oxide (SnO2) thick films and their use as gas sensors. The doping percentage (Dy3+) was varied from 1xa0mol.% to 4xa0mol.% with the step of 1xa0mol.%. As-produced material with varying doping levels were sintered in air; and by using a screen printing technique, their thick films were developed. Prior to sensing performance investigations, the films were examined for structural, morphological and compositional properties using x-ray diffraction, a field emission scanning electron microscope, a transmission electron microscope, selected area electron diffraction, energy dispersive analysis by x-rays, Fourier transform infrared spectroscopy and Raman spectroscopic techniques. The structural analyses revealed formation of single phase nanocrystalline material with tetragonal rutile structure of SnO2. The morphological analyses confirmed the nanocrystalline porous morphology of as-developed material. Elemental analysis defined the composition of material in accordance with the doping concentration. The produced sensor material exhibited good response towards different reducing gases (acetone, ethanol, LPG, and ammonia) at different operating temperatures. The present study confirms that the Dy3+ doping in SnO2 enhances the response towards ethanol with reduction in operating temperature. Particularly, 3xa0mol.% Dy3+ doped sensor exhibited the highest response (∼u200992%) at an operating temperature of 300°C with better selectivity, fast response (∼u200913xa0s) and recovery (∼u200922xa0s) towards ethanol.Graphical AbstractThe concise representation of conducted work: (a) EDAX, (b) ethanol sensing mechanism, (c) sensor response, and (d) SEM image of Dy: SnO2 nanoparticles.n