Sandeep Chhoker
@jiit.ac.in
ASSOCIATE PROFESSOR
JIIT Noida
RESEARCH, TEACHING, or OTHER INTERESTS
Materials Science, Materials Chemistry, Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Chandresh Kumari, Sandeep Chhoker, and Pankaj Sharma
Springer Science and Business Media LLC
Chandresh Kumari, Pankaj Sharma, and Sandeep Chhoker
AIP Publishing
Saurabh Rawat, Priyanka Bamola, Shreya Negi, Karishma, Chanchal Rani, Shivani Dangwal, Archana Mishra, Manika Khanuja, A. K. Yogi, Sandeep Chhoker,et al.
American Chemical Society (ACS)
Tanushree Ghosh, Love Bansal, Suchita Kandpal, Chanchal Rani, Deb Kumar Rath, Bhumika Sahu, Sandeep Chhoker, and Rajesh Kumar
Elsevier BV
Chandresh Kumari, Sandeep Chhoker, and Pankaj Sharma
Elsevier BV
Deepali Aswal, Priyanka Bamola, Chanchal Rani, Saurabh Rawat, Abhinav Bhatt, Sandeep Chhoker, Mohit Sharma, Charu Dwivedi, Rajesh Kumar, and Himani Sharma
Wiley
AbstractTwo‐dimensional (2D) tungsten disulphide (WS2) based heterostructures with modified interfaces have huge potential for photocatalytic applications. Integrating WS2 with one‐dimensional (1D) titanium dioxide (TiO2) and 2D molybdenum disulphide (MoS2) structures to form heterostructures, enhances its photocatalytic activity. The enrichment in photocatalytic activity of heterostructures may get affected by the electronic interaction at the interface as well as morphology and dimensionality also affect the catalytic activity. In this context, the present work focuses on the enrichment of photocatalytic activity by different tungsten disulphide (WS2) based heterostructures, which may get influenced by the interfacial interaction. In the present work, two different heterostructures 2D‐1D WS2/TiO2 and 2D‐2D MoS2/WS2 are formed using the hydrothermal method. Scanning electron microscopy (SEM) confirmed the morphology of prepared heterostructures. X‐ray photoelectron spectroscopy (XPS) analysis further revealed that the integration of 1D and 2D nanostructures with WS2 has been found effective to alter the interface by the development of the Ohmic and Schottky barrier. Moreover, Fourier transformation infra‐red (FTIR) spectroscopy confirms the presence of W−S, S−S, Mo−S, and Ti−O bonds in the prepared heterostructures. Furthermore, current‐voltage (I–V) data graphically illustrated the conductivity of catalysts. I–V curves confirm the presence of Schottky and ohmic barriers and the higher electrical conductivity of 2D‐2D MoS2/WS2 heterostructures, which facilitates the charge carrier's transportation. 2D‐1D WS2/TiO2 and 2D‐2D MoS2/WS2 heterostructures are further explored for photocatalytic activity by the methylene blue dye degradation. The overall catalytic activity of 2D‐2D MoS2/WS2 is better than 2D‐1D WS2/TiO2 and WS2, respectively. This result was accounted as 2D‐2D MoS2/WS2 had the highest conductivity and better charge separation at the interface in comparison to the other two synthesised catalysts.
Love Bansal, Tanushree Ghosh, Suchita Kandpal, Chanchal Rani, Bhumika Sahu, Deb Kumar Rath, Christoph Wesemann, Sandeep Chhoker, Nadja C. Bigall, and Rajesh Kumar
Royal Society of Chemistry (RSC)
Microcrystalline MoO3 powder, possessing supercapacitive energy storage capability, shows interesting HF sensing performance with a high sensitivity of 6656 mF mM−1 g−1 and a low limit of detection of 1.2 μM.
Love Bansal, Chanchal Rani, Tanushree Ghosh, Suchita Kandpal, Sandeep Chhoker, Manushree Tanwar, and Rajesh Kumar
American Chemical Society (ACS)
Ambika Pathak, Sandeep Chhoker, Pinky Singh, Himani Sharma, and Rajesh Kumar
Elsevier BV
Chandresh Kumari, Pankaj Sharma, Manushree Tanwar, Himani Sharma, Rajesh Kumar, and Sandeep Chhoker
Elsevier BV
Chandresh Kumari, Pankaj Sharma, S.C. Katyal, Manushree Tanwar, Priyanka Bamola, Himani Sharma, Rajesh Kumar, and Sandeep Chhoker
Elsevier BV
Chandresh Kumari, Pankaj Sharma, S.C. Katyal, and Sandeep Chhoker
Elsevier BV
Chandresh Kumari, S C Katyal, Sandeep Chhoker, and Pankaj Sharma
IOP Publishing
Abstract Selenium-based chalcogenide glasses show tremendous infrared transmission in the 2–15 μm region, and these amorphous glasses could be easily formed into optical devices i.e. optical fibers and lenses, owing to their good thermo-mechanical properties. Even though the phonon energy for tellurium-based glasses is on the lower side, still, selenium-based glasses are worthwhile for mid to long-wavelength infrared emissions. Here, we have developed Er-doped selenium-based, Ge 17 Sb 8 Se 75−x Er x where x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0, chalcogenides by conventional melting and quenching technique for possible mid to far-infrared applications. Far-infrared transmission spectra of the synthesized chalcogenides are obtained at room temperature in the spectral range of 35–450 cm−1. The bonding arrangements in the synthesized chalcogenides are investigated as a function of composition. It has been found that with the addition of Er content, the far-infrared transmission spectra shift toward the lower wavenumber side. The experimental results are correlated with the theoretically calculated parameters such as relative probability, bond energy, wave number, force constant etc. The obtained results provide insight into understanding the synthesized chalcogenides’ optical behavior, which is dynamic for designing the optical components operated in mid-infrared to far-infrared regions.
Chandresh Kumari, Pankaj Sharma, and Sandeep Chhoker
IEEE
Quaternary chalcogenide system has potential material in semiconducting electronic applications because of the narrow band gap and excellent optical and electronic properties in MIR to NIR range. Many researchers have shown great interest in photocatalytic studies because of their environmentally friendly nature. In this article, the Ge17 SbS S$\\mathrm{e}_{75-\\mathrm{x}}E\\mathrm{r}_{\\mathrm{x}}$(x=0,0.2) chalcogenide system has been reported for the photodegradation of cationic dye in the UV-cut region. The bulk powder chalcogenide has been synthesized using the melt-quench technique, and its structural studies have been performed. It is found thatO.2 of Er-doped chalcogenide shows a degradation of 83% in 210 min for cationic methylene blue dye. First-order kinetics has been fitted to understand the photocatalytic rate phenomenon. In contrast, a band diagram for photocatalytic splitting has been proposed to understand the degradation mechanism. Overall, considering the suitability for parameter tailoring, this material has the potential to compete with existing binary and ternary catalysts.
Shalu Sharma and Sandeep Chhoker
Springer Science and Business Media LLC
Shalu Sharma and Sandeep Chhoker
Springer Science and Business Media LLC
AbstractHere, we report the systematic studies on photoanodes of phase pure polycrystalline microrods of Barium Stannate (BaSnO3) microrods for application in porphyrin dye-sensitized solar cell (DSSC). We were able to establish the effect of vacuum annealing on BaSnO3 thin films on its electrical, optical and adsorption properties using XPS, UV–Vis, photoluminescence and adsorption isotherm studies. Increase in oxygen vacancy with annealing is found to increase the room temperature (RT) electron mobility from 49.1 to 82.4 cm2/V sec whereas macroporous nature of samples were found suitable for faster dye adsorption (~ 30 min). Post TiCl4 treatment studies, the maximum efficiency (η) of 4.7% is achieved in BSO films with current density Jsc ~ value as 10.4 mA/cm2; whereas DSSC fabricated using annealed BSO films gave maximum efficiency of 6.1% with Jsc value as 12.2 mA/cm2, during which the value of FF increased from 73.4 to 81%. The IPCE and proposed electron transfer mechanism suggested the potential application of macroporous BSO with unconventional dyes such as metallised-porphyrin. Our results strengthen the idea of using phase-pure, visible transparent porous BSO nanostructures with induced oxygen vacancies due to annealing process post-synthesis which eventually increased DSSC performance from by 84%.
Shalu Sharma and Sandeep Chhoker
Elsevier BV
Sunil Chauhan, Manoj Kumar, Himanshu Pandey, Sandeep Chhoker, and S.C. Katyal
Elsevier BV
Seema Josh, Manoj Kumar, Himanshu Pandey, and Sandeep Chhoker
AIP Publishing
Himanshu Pandey, S. Chhoker, B. C. Joshi, and D. Tripathi
AIP Publishing
Shalu Sharma, Manoj Kumar, and Sandeep Chhoker
Elsevier BV
Shalu Sharma, Manoj Kumar, and Sandeep Chhoker
Author(s)
Sandeep Chhoker and Shalu Sharma
Author(s)
Single step growth of carbon nanoflakes over p-silicon (100) substrates in MPECVD system using acetylene, hydrogen and argon as reactant gases has been carried out. FESEM studies of the deposited carbon films revealed that the morphology is greatly influenced with deposition time. Transmission electron microscope (TEM) and Raman spectra analysis of these thin films confirmed presence of highly crystalline carbon films growth. Its surface activation properties have been studied by depositing ultra thin layer of RbF over 2D carbon nanoflake films and corresponding KP (Kelvin-Probe) measurements.
Sunil Chauhan, Manoj Kumar, Himanshu Pandey, and Sandeep Chhoker
Author(s)
Bi1-xCaxFe1-xNixO3 nanoparticles with x = 0.0, 0.05, 0.10 and 0.15 were effectively synthesized using a profitable route, tartaric acid based sol-gel one. In BiFeO3 at Bi and Fe-sites, the co-substitution of alkali earth metal Ca2+ ions and transition metal Ni2+ ions leads to structural distortion, reduction in average grain size and enhanced magnetic properties. The study of XRD and Raman scattering demonstrated the compressive lattice distortion in the samples occurred from the co-substitution of Ca2+ and Ni2+ ions. The measurements of XRD patterns and Raman spectroscopy also recommended the coexistence of rhombohedral and orthorhombic phases in co-substituting BiFeO3 samples. Room temperature enhanced ferromagnetic behavior demonstrated with magnetic study, by the co-substitution of Ca2+ and Ni2+ ions at Bi and Fe-site, respectively. The line shape of electron paramagnetic resonance spectra changes continuously due to the local distortion caused from substituting Ni.
Shalu Sharma, Himanshu Pandey, Manoj Kumar, and Sandeep Chhoker
Elsevier BV