@article{14828,
  abstract     = {Production of hydrogen at large scale requires development of non-noble, inexpensive, and high-performing catalysts for constructing water-splitting devices. Herein, we report the synthesis of Zn-doped NiO heterostructure (ZnNiO) catalysts at room temperature via a coprecipitation method followed by drying (at 80 °C, 6 h) and calcination at an elevated temperature of 400 °C for 5 h under three distinct conditions, namely, air, N2, and vacuum. The vacuum-synthesized catalyst demonstrates a low overpotential of 88 mV at −10 mA cm–2 and a small Tafel slope of 73 mV dec–1 suggesting relatively higher charge transfer kinetics for hydrogen evolution reactions (HER) compared with the specimens synthesized under N2 or O2 atmosphere. It also demonstrates an oxygen evolution (OER) overpotential of 260 mV at 10 mA cm–2 with a low Tafel slope of 63 mV dec–1. In a full-cell water-splitting device, the vacuum-synthesized ZnNiO heterostructure demonstrates a cell voltage of 1.94 V at 50 mA cm–2 and shows remarkable stability over 24 h at a high current density of 100 mA cm–2. It is also demonstrated in this study that Zn-doping, surface, and interface engineering in transition-metal oxides play a crucial role in efficient electrocatalytic water splitting. Also, the results obtained from density functional theory (DFT + U = 0–8 eV), where U is the on-site Coulomb repulsion parameter also known as Hubbard U, based electronic structure calculations confirm that Zn doping constructively modifies the electronic structure, in both the valence band and the conduction band, and found to be suitable in tailoring the carrier’s effective masses of electrons and holes. The decrease in electron’s effective masses together with large differences between the effective masses of electrons and holes is noticed, which is found to be mainly responsible for achieving the best water-splitting performance from a 9% Zn-doped NiO sample prepared under vacuum.},
  author       = {Kiran, Gundegowda Kalligowdanadoddi and Singh, Saurabh and Mahato, Neelima and Sreekanth, Thupakula Venkata Madhukar and Dillip, Gowra Raghupathy and Yoo, Kisoo and Kim, Jonghoon},
  issn         = {2574-0962},
  journal      = {ACS Applied Energy Materials},
  keywords     = {Electrical and Electronic Engineering, Materials Chemistry, Electrochemistry, Energy Engineering and Power Technology, Chemical Engineering (miscellaneous)},
  number       = {1},
  pages        = {214--229},
  publisher    = {American Chemical Society},
  title        = {{Interface engineering modulation combined with electronic structure modification of Zn-doped NiO heterostructure for efficient water-splitting activity}},
  doi          = {10.1021/acsaem.3c02519},
  volume       = {7},
  year         = {2024},
}

@article{14379,
  abstract     = {We report on a simple surfactant/template free chemical route for the synthesis of semi-polycrystalline polyaniline-graphite (SPani-graphite) composite and its application as an electroactive material in electrochemical charge storage. The synthesized material exhibits well-defined poly-crystallographic lattices in high resolution transmission electron micrographs and sharp peaks in x-ray diffraction spectra suggesting crystalline nature of the material. The specific capacitance computed from the galvanostatic charge-discharge (GCD) data obtained from 3-electrode cell configuration using 1 M aq. Na2SO4 as an electrolyte was 111.4 F g−1 at a current density of 0.1 A g−1 which rises to 269 F g−1 at an elevated current density of 1.0 A g−1. A similar pattern of increase in the specific capacitance values with an increase in the current density was observed in the results obtained from 2-electrode symmetric device configuration using polymer gel electrolyte (xanthan gum in 1 M aq. Na2SO4). The specific capacitance computed from the GCD data obtained from the device configuration was 20 F g−1 at the current density of 1.0 A g−1. The device delivers an energy density of 1.7 Wh kg−1 and a power density of 2.48 kWh kg−1 at an applied current density of 0.5 A g−1 suggesting an excellent rate capability and power management. In addition, the device exhibits ⁓92 % specific capacitance retention up to 8000 continuous GCD cycles and ⁓80 % coulombic efficiency up to 10,000 continuous GCD cycles indicating excellent cycling stability. The unique feature of increasing specific capacitance with respect to applied current density is attributed to the presence of semi-polycrystalline phases in the SPani-graphite matrix. The material behaves as a surface redox supercapacitor and its unique mechanism of charge storage is discussed in detail in the article.},
  author       = {Mahato, Neelima and Singh, Saurabh and Faisal, Mohammad and Sreekanth, T. V.M. and Majumder, Sutripto and Yoo, Kisoo and Kim, Jonghoon},
  issn         = {0379-6779},
  journal      = {Synthetic Metals},
  publisher    = {Elsevier},
  title        = {{Polycrystalline phases grown in-situ engendering unique mechanism of charge storage in polyaniline-graphite composite}},
  doi          = {10.1016/j.synthmet.2023.117463},
  volume       = {299},
  year         = {2023},
}

@article{14652,
  abstract     = {In order to demonstrate the stability of newly proposed iridium-based Ir2Cr(In,Sn) and IrRhCr(In,Sn) heusler alloys, we present ab-initio analysis of these alloys by examining various properties to prove their stability. The stability of these alloys can be inferred from different cohesive and formation energies as well as positive phonon frequencies. Their electronic structure results indicate that they are semi-metals in nature. The magnetic moments are computed using the Slater-Pauling formula and exhibit a high value, with the Cr atom contributing the most in all alloys. Mulliken’s charge analysis results show that our alloys contain a range of linkages, mainly ionic and covalent ones. The ductility and mechanical stability of these alloys are confirmed by elastic constants viz. Poisson’s ratio, Pugh’s ratio, and many different types of elastic moduli.},
  author       = {Gupta, Shyam Lal and Singh, Saurabh and Kumar, Sumit and Anupam, Unknown and Thakur, Samjeet Singh and Kumar, Ashish and Panwar, Sanjay and Diwaker, D.},
  issn         = {0921-4526},
  journal      = {Physica B: Condensed Matter},
  publisher    = {Elsevier},
  title        = {{Ab-initio stability of Iridium based newly proposed full and quaternary heusler alloys}},
  doi          = {10.1016/j.physb.2023.415539},
  volume       = {674},
  year         = {2023},
}

@article{14777,
  abstract     = {The effects of the partial V-substitution for Ag on the thermoelectric (TE) properties are investigated for a flexible semiconducting compound Ag2S0.55Se0.45. Density functional theory calculations predict that such a partial V-substitution constructively modifies the electronic structure near the bottom of the conduction band to improve the TE performance. The synthesized Ag1.97V0.03S0.55Se0.45 is found to possess a TE dimensionless figure-of-merit (ZT) of 0.71 at 350 K with maintaining its flexible nature. This ZT value is relatively high in comparison with those reported for flexible TE materials below 360 K. The increase in the ZT value is caused by the enhanced absolute value of the Seebeck coefficient with less significant variation in electrical resistivity. The high ZT value with the flexible nature naturally allows us to employ the Ag1.97V0.03S0.55Se0.45 as a component of flexible TE generators.},
  author       = {Sato, Kosuke and Singh, Saurabh and Yamazaki, Itsuki and Hirata, Keisuke and Ang, Artoni Kevin R. and Matsunami, Masaharu and Takeuchi, Tsunehiro},
  issn         = {2158-3226},
  journal      = {AIP Advances},
  keywords     = {General Physics and Astronomy},
  number       = {12},
  publisher    = {AIP Publishing},
  title        = {{Improvement of thermoelectric performance of flexible compound Ag2S0.55Se0.45 by means of partial V-substitution for Ag}},
  doi          = {10.1063/5.0171888},
  volume       = {13},
  year         = {2023},
}