• SANJEEB LIMBU

      Articles written in Bulletin of Materials Science

    • Investigation of crystal structure confinement and optical attributes of monoclinic–tetragonal Zirconia nanocrystals via chemical co-precipitation technique

      SANJEEB LIMBU

      More Details Abstract Fulltext PDF

      Mn-activated ZrO$_2$ nanocrystal was successfully synthesized using the chemical co-precipitation technique. Nanocrystals have been widely studied in terms of their structural and optical aspects. X-ray diffraction (XRD) analysis confirmed the formation of monoclinic and tetragonal phases in pure and Mn-doped ZrO$_2$ nanocrystals. The unit cell structure of m-ZrO$_2$ and t-ZrO$_2$ has been modelled using the Rietveld refinement crystallographic data. A photoluminescence (PL) study revealed emission intensity peaks at 378 nm for pure ZrO$_2$ and 380 nm for Mn-doped ZrO$_2$ nanocrystal under 280 nm excitation. A significant red shift was observed in Mn-doped ZrO$_2$ nanocrystal due to the oxygen vacancy. The incorporation of Mn to ZrO$_2$ nanocrystals reduced the optical band gap from 5.07 to 2.02 eV. The morphological analysis revealed that the typical particle sizes were in the nanoscale range, with 38 nm for pure ZrO$_2$ and 70 nm for Mn-doped ZrO$_2$ nanocrystals.

    • Correlation between different characterizations and improved electrochemical performances of cuprous oxide-based nanocrystals

      NAVEEN KUMAR SANJEEB LIMBU RAM NARAYAN CHAUHAN

      More Details Abstract Fulltext PDF

      Herein, we employed the sol–gel technique to synthesize Cu$_2$O-based nanocrystals with Co and Na doping and co-doping, respectively. A correlation was established among several characterizations of cuprous oxide-based nanocrystals to observe their feasibility in the field of energy materials. Raman spectra typically show the formation of Cu$_2$O, whereas, in the case of Na co-doping, it exhibits the partial presence of CuO. This form of the results prompts the conductivity of nanocrystal samples to be enhanced. According to the current–voltage measurement, the current response slightly increases as doping and co-doping concentrations rise, in which Na5% co-doped Cu$_2$O:Co shows the optimum. Photoluminescence (PL) lifetime measurement shows increases in relative PL lifetime intensity caused by Na doping, which may be attributed to oxygen vacancies. Moreover, it is observed from the cyclic voltammetry (CV) profile that the Na and Co-doped concentration significantly enhances energy storage capability. The electrode using Na5%Cu$_2$O:Co has shown capacitive retention of 69% after 500 GCD cycles @ 10 A g$^{–1}$. This indicates the practical applicability of these developed cuprous oxide-based nanocrystals as electrode materials for improved electrochemical property. Eventually, the charge–discharge was performed at different current densities, in which specific capacitance was consistent with the CV result.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.