Sachin Sawant - Academia.edu (original) (raw)
Papers by Sachin Sawant
Journal of Nano- and Electronic Physics
Rapid synthesis of Cu2O nanoparticles was carried out by wet chemical synthesis technique. The ef... more Rapid synthesis of Cu2O nanoparticles was carried out by wet chemical synthesis technique. The effect of CuSO4 precursor molar concentration (0.05-0.15 mol) on the structural, morphological and optical properties of Cu2O nanoparticles is reported. X-ray diffraction analysis of the synthesized Cu2O powder shows a cubic structure with nanocrystalline nature. The average crystallite size of Cu2O nanoparticles increases from 10 to 25 nm with increasing precursor molarity. Scanning Electron Microscopic (SEM) analysis shows nanocrystalline Cu2O formation with increased particle size due to rise in molarity. The FTIR spectroscopic analysis ascertains the presence of characteristic functional groups in Cu2O. UV-Vis spectra show a characteristic absorbance peak around 485 nm attributed to Cu2O. The energy band gap measurements from the Tauc plot reveal a decrease in band gap energy with increasing precursor molarity owing to increased grain size. The band gap energy decreases from 2.94 to 2.64 eV due to an increase in the grain size mainly due to quantum confinement effect.
Journal of Wuhan University of Technology-Mater. Sci. Ed., 2019
A n effect of heating and stir r ing in a facile w et chemical r ou t e to synthesiz e entangled ... more A n effect of heating and stir r ing in a facile w et chemical r ou t e to synthesiz e entangled nanofibrous mesh of doped polyaniline (PANI) was reported. The structural, morphological, and optical properties of PANI nano-fibers were found to be dependent on synthesis temperature and stirring. The XRD analysis confirms nano PANI formation with 2θ peaks around 15°, 21°, and 25° for (011), (020), and (200) crystal planes, respectively. The average crystallite size varies between 25 nm to 60 nm due to change in synthesis conditions. The SEM analysis reveals the clustered granule formation for PANI sample synthesized at 28 and 60 ℃ u nde r continuous stirring, whereas, unstirred synthesis at 60 ℃ shows entangled nano-fibrous mesh morphology. The TGA study shows better thermal stability for PANI mesh over granular PANI. The FTIR spectra validates the emeraldine salt PANI formation with peaks corresponding to C-H, C-N, N=Q=N, N=B=N, and N-H vibration bands. The UV-Vis analysis shows the major absorbance peaks around λ: 340 nm (π-π* transition of benzenoid ring), and λ: 800 nm (π-π* , polaron-π* , π-polaron transitions). The dense entangled nano-fibrous coating of PANI synthesized at 60 ℃ without stirring shows highest electrical conductivity of 3.79 S•cm-1 .
Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-... more Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-gel obtained was washed and calcinated at 400 C to obtain the SnO2 nano-powder. The structural property of (SnO2) nanocrystalline powder was investigated by using X-ray diffraction (XRD) technique. The optical properties were studied using Uv-Vis Spectroscopy, by recording the absorbance and transmittance spectra. The XRD pattern of the as-prepared sample demonstrated the formation of a rutile structure of SnO2 nanocrystallites. The Scanning Electron Microscopic (SEM) analysis showed a homogeneous distribution of quite small grains over scanned area. The Uv-Vis absorbance spectra also showed a characteristic peak of absorbance at 312 nm corresponding to SnO2. The energy band gap measurement for nanocrystalline SnO2 thin film was done from the graph of variation of (hν)2 versus hν. The measured value of optical bandgap energies for SnO2 thin film is 3.78 eV. The results show that th...
Journal of Nano- and Electronic Physics, 2016
Nanocrystalline ZnO thin films were deposited by intermittent spray pyrolysis using different alc... more Nanocrystalline ZnO thin films were deposited by intermittent spray pyrolysis using different alcoholic and aqua-alcoholic precursor solvents. The XRD analysis reveals the polycrystallinity of hexagonal wurtzite type ZnO films with preferred c-axis orientation along [002] direction. The polycrystallinity increased due to use of aqua-alcoholic precursor solvent. The crystallite size was found to vary from 41.7 nm to 59.4 nm and blue shift in band-gap energy (3.225 eV to 3.255 eV) was observed due to aqua-alcoholic to alcoholic precursor solvent transition. The films deposited using alcoholic precursor solvent exhibited high transmittance ( 92 %) with low dark resistivity (10-3 Ωcm) as compared to aqua-alcoholic precursor solvent. The effect of precursor solvent on resistivity, carrier concentration (-/cm 3), carrier mobility (cm 2 V-1 s-1), sheet resistance (Ω/) and figure of merit (ΦTC) is also reported. We recommend ethanol or methanol as a superior precursor solvent over aqua-alcoholic precursor solvent for deposition of device quality ZnO thin films.
Journal of Nano- and Electronic Physics, 2016
A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative po... more A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative polymerization of aniline hydrochloride and ammonium persulfate at high temperature (60 C). The structural and optical properties of PANI nanofibers are investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The XRD analysis ascertains formation of PANI with nanocrystalline nature with average crystallite size 30 nm. Further, FTIR pattern confirmed the formation of PANI. SEM analysis has revealed homogeneous fibrous morphology of PANI nanofibers, a well formed mesh of interconnected and entangled PANI nano-fibers over the scanned area. The UV-VIS spectroscopic analysis shows three major absorption peaks at 256.73, 361.17 and 480.95 nm confirmed the PANI formation with conducting state.
Journal of Nano- and Electronic Physics, 2016
Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains... more Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains significant importance for its synthesis in view of its various technological and industrial applications. A few liquid phase methods for the synthesis of Cu2O nanoparticles are reviewed on the basis of materials, methodology, synthesis conditions and key findings. A comparative study of these methods is also performed following criteria of repeatability, safety, cost, time span and simplicity. Contextual to the above mentioned criteria, three liquid phase synthesis techniques were shortlisted and actually experimented (as reported) to synthesize the Cu2O nanoparticles. This was done to investigate the effectiveness, repeatability and stability of the synthesized Cu2O product as a function of ageing time. The synthesized Cu2O using all these techniques are prone to be unstable and undergo the rapid phase change to CuO phase which was ascertained from the shift of absorbance peak in UV-VIS spectra. The results have highlighted the urgent need to develop a facile, economical, scalable and safe method to synthesize stable Cu2O nanoparticles at room temperature.
Journal of Nano- and Electronic Physics, 2016
A novel facile method to synthesize stable phase of Cuprous Oxide (Cu2O) nanoparticles at room te... more A novel facile method to synthesize stable phase of Cuprous Oxide (Cu2O) nanoparticles at room temperature is demonstrated. The structural and optical properties of (Cu2O) nanoparticles were investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy. XRD analysis has indexed nanocrystalline nature of cubical phase Cu2O with an average edge length of about 20 nm. The Scanning Electron Microscopy (SEM) measurements also ascertain the cubical morphology. The Fourier Transform Infrared Spectroscopy (FTIR) affirms the presence of characteristic functional group of Cu2O. The absorbance peak at 485 nm in UV-VIS spectra also confirms the Cu2O synthesis. Furthermore, UV-VIS absorbance spectra at different ageing time substantiate the phase stability of Cu2O nanoparticles. The ageing leads to blue shift of absorbance peak mainly due to decrease in Cu2O particle size with no additional absorbance peak in UV-VIS spectra indicating the formation of secondary phase. The reduction in particle size may be attributed to tiny conversion Cu2O to CuO. The energy band gap measurements from Tauc plots for Cu2O nanoparticles shows the increasing trend (2.5 eV to 2.8 eV) with ageing time (2 months), owing to quantum confinement effects.
Journal of Nano- and Electronic Physics
Rapid synthesis of Cu2O nanoparticles was carried out by wet chemical synthesis technique. The ef... more Rapid synthesis of Cu2O nanoparticles was carried out by wet chemical synthesis technique. The effect of CuSO4 precursor molar concentration (0.05-0.15 mol) on the structural, morphological and optical properties of Cu2O nanoparticles is reported. X-ray diffraction analysis of the synthesized Cu2O powder shows a cubic structure with nanocrystalline nature. The average crystallite size of Cu2O nanoparticles increases from 10 to 25 nm with increasing precursor molarity. Scanning Electron Microscopic (SEM) analysis shows nanocrystalline Cu2O formation with increased particle size due to rise in molarity. The FTIR spectroscopic analysis ascertains the presence of characteristic functional groups in Cu2O. UV-Vis spectra show a characteristic absorbance peak around 485 nm attributed to Cu2O. The energy band gap measurements from the Tauc plot reveal a decrease in band gap energy with increasing precursor molarity owing to increased grain size. The band gap energy decreases from 2.94 to 2.64 eV due to an increase in the grain size mainly due to quantum confinement effect.
Journal of Wuhan University of Technology-Mater. Sci. Ed., 2019
A n effect of heating and stir r ing in a facile w et chemical r ou t e to synthesiz e entangled ... more A n effect of heating and stir r ing in a facile w et chemical r ou t e to synthesiz e entangled nanofibrous mesh of doped polyaniline (PANI) was reported. The structural, morphological, and optical properties of PANI nano-fibers were found to be dependent on synthesis temperature and stirring. The XRD analysis confirms nano PANI formation with 2θ peaks around 15°, 21°, and 25° for (011), (020), and (200) crystal planes, respectively. The average crystallite size varies between 25 nm to 60 nm due to change in synthesis conditions. The SEM analysis reveals the clustered granule formation for PANI sample synthesized at 28 and 60 ℃ u nde r continuous stirring, whereas, unstirred synthesis at 60 ℃ shows entangled nano-fibrous mesh morphology. The TGA study shows better thermal stability for PANI mesh over granular PANI. The FTIR spectra validates the emeraldine salt PANI formation with peaks corresponding to C-H, C-N, N=Q=N, N=B=N, and N-H vibration bands. The UV-Vis analysis shows the major absorbance peaks around λ: 340 nm (π-π* transition of benzenoid ring), and λ: 800 nm (π-π* , polaron-π* , π-polaron transitions). The dense entangled nano-fibrous coating of PANI synthesized at 60 ℃ without stirring shows highest electrical conductivity of 3.79 S•cm-1 .
Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-... more Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-gel obtained was washed and calcinated at 400 C to obtain the SnO2 nano-powder. The structural property of (SnO2) nanocrystalline powder was investigated by using X-ray diffraction (XRD) technique. The optical properties were studied using Uv-Vis Spectroscopy, by recording the absorbance and transmittance spectra. The XRD pattern of the as-prepared sample demonstrated the formation of a rutile structure of SnO2 nanocrystallites. The Scanning Electron Microscopic (SEM) analysis showed a homogeneous distribution of quite small grains over scanned area. The Uv-Vis absorbance spectra also showed a characteristic peak of absorbance at 312 nm corresponding to SnO2. The energy band gap measurement for nanocrystalline SnO2 thin film was done from the graph of variation of (hν)2 versus hν. The measured value of optical bandgap energies for SnO2 thin film is 3.78 eV. The results show that th...
Journal of Nano- and Electronic Physics, 2016
Nanocrystalline ZnO thin films were deposited by intermittent spray pyrolysis using different alc... more Nanocrystalline ZnO thin films were deposited by intermittent spray pyrolysis using different alcoholic and aqua-alcoholic precursor solvents. The XRD analysis reveals the polycrystallinity of hexagonal wurtzite type ZnO films with preferred c-axis orientation along [002] direction. The polycrystallinity increased due to use of aqua-alcoholic precursor solvent. The crystallite size was found to vary from 41.7 nm to 59.4 nm and blue shift in band-gap energy (3.225 eV to 3.255 eV) was observed due to aqua-alcoholic to alcoholic precursor solvent transition. The films deposited using alcoholic precursor solvent exhibited high transmittance ( 92 %) with low dark resistivity (10-3 Ωcm) as compared to aqua-alcoholic precursor solvent. The effect of precursor solvent on resistivity, carrier concentration (-/cm 3), carrier mobility (cm 2 V-1 s-1), sheet resistance (Ω/) and figure of merit (ΦTC) is also reported. We recommend ethanol or methanol as a superior precursor solvent over aqua-alcoholic precursor solvent for deposition of device quality ZnO thin films.
Journal of Nano- and Electronic Physics, 2016
A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative po... more A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative polymerization of aniline hydrochloride and ammonium persulfate at high temperature (60 C). The structural and optical properties of PANI nanofibers are investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The XRD analysis ascertains formation of PANI with nanocrystalline nature with average crystallite size 30 nm. Further, FTIR pattern confirmed the formation of PANI. SEM analysis has revealed homogeneous fibrous morphology of PANI nanofibers, a well formed mesh of interconnected and entangled PANI nano-fibers over the scanned area. The UV-VIS spectroscopic analysis shows three major absorption peaks at 256.73, 361.17 and 480.95 nm confirmed the PANI formation with conducting state.
Journal of Nano- and Electronic Physics, 2016
Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains... more Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains significant importance for its synthesis in view of its various technological and industrial applications. A few liquid phase methods for the synthesis of Cu2O nanoparticles are reviewed on the basis of materials, methodology, synthesis conditions and key findings. A comparative study of these methods is also performed following criteria of repeatability, safety, cost, time span and simplicity. Contextual to the above mentioned criteria, three liquid phase synthesis techniques were shortlisted and actually experimented (as reported) to synthesize the Cu2O nanoparticles. This was done to investigate the effectiveness, repeatability and stability of the synthesized Cu2O product as a function of ageing time. The synthesized Cu2O using all these techniques are prone to be unstable and undergo the rapid phase change to CuO phase which was ascertained from the shift of absorbance peak in UV-VIS spectra. The results have highlighted the urgent need to develop a facile, economical, scalable and safe method to synthesize stable Cu2O nanoparticles at room temperature.
Journal of Nano- and Electronic Physics, 2016
A novel facile method to synthesize stable phase of Cuprous Oxide (Cu2O) nanoparticles at room te... more A novel facile method to synthesize stable phase of Cuprous Oxide (Cu2O) nanoparticles at room temperature is demonstrated. The structural and optical properties of (Cu2O) nanoparticles were investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy. XRD analysis has indexed nanocrystalline nature of cubical phase Cu2O with an average edge length of about 20 nm. The Scanning Electron Microscopy (SEM) measurements also ascertain the cubical morphology. The Fourier Transform Infrared Spectroscopy (FTIR) affirms the presence of characteristic functional group of Cu2O. The absorbance peak at 485 nm in UV-VIS spectra also confirms the Cu2O synthesis. Furthermore, UV-VIS absorbance spectra at different ageing time substantiate the phase stability of Cu2O nanoparticles. The ageing leads to blue shift of absorbance peak mainly due to decrease in Cu2O particle size with no additional absorbance peak in UV-VIS spectra indicating the formation of secondary phase. The reduction in particle size may be attributed to tiny conversion Cu2O to CuO. The energy band gap measurements from Tauc plots for Cu2O nanoparticles shows the increasing trend (2.5 eV to 2.8 eV) with ageing time (2 months), owing to quantum confinement effects.