School Of Basic And Applied Sciences

Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/17

Browse

Subject: search.filters.subject.Chemical stability

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Cu-Metal Organic Framework Derived Multilevel Hierarchy (Cu/CuxO@NC) as a Bifunctional Electrode for High-Performance Supercapacitors and Oxygen Evolution Reaction
    (American Chemical Society, 2023-05-25T00:00:00) Abbas, Zahir; Hussain, Nissar; Ahmed, Imtiaz; Mobin, Shaikh M.
    The development of a MOFs-derived multilevel hierarchy in a single step still remains a challenging task. Herein, we have synthesized novel Cu-MOF via a slow diffusion method at ambient temperature and further utilized it as a precursor source for MOF-derived multilevel hierarchy (Cu/CuxO@NC, x = 1 and 2). This studies suggest that the organic ligands served as a source of an N-doped carbon matrix encapsulated with metal oxide nanoparticles which were confirmed by various characterization techniques; further BET analysis reveals a surface area of 178.46 m2/g. The synthesized multilevel hierarchy was utilized as an electro-active material in a supercapacitor that achieved a specific capacitance of 546.6 F g-1 at a current density of 1 A g-1 with a higher cyclic retention of 91.81% after 10 000 GCD cycles. Furthermore, the ASC device was fabricated using Cu/CuxO@NC as the positive electrode and carbon black as the negative electrode and utilized to enlighten the commercially available LED bulb. The fabricated ASC device was further employed for a two-electrode study which achieved a specific capacitance of 68 F g-1 along with a comparable energy density of 13.6 Wh kg-1. Furthermore, the electrode material was also explored for the oxygen evolution reaction (OER) in an alkaline medium with a low overpotential of 170 mV along with a Tafel slope of 95 mV dec-1 having long-term stability. The MOF-derived material has high durability, chemical stability, and efficient electrochemical performance. This work provides some new thoughts for the design and preparation of a multilevel hierarchy (Cu/CuxO@NC) via a single precursor source in a single step and explored multifunctional applications in energy storage and an energy conversion system. � 2023 American Chemical Society.
  • Thumbnail Image
    Item
    Relative stabilities and the spectral signatures of stacked and hydrogen-bonded dimers of serotonin
    (Taylor and Francis Ltd., 2015) Dev, S.; Giri,Kousik; Majumder, M.; Sathyamurthy, N.; Dev, S.; Giri, K.; Majumder, M.; Sathyamurthy, N.
    The O-HsssN hydrogen-bonded dimer of serotonin is shown to be more stable than the stacked dimer in its ground electronic state, by using the M?ller-Plesset second-order perturbation theory (MP2) and the 6-31g??basis set. The vertical excitation energy for the lowest ? ? ?? transition for the monomer as well as the dimer is predicted by time-dependent density functional theory. The experimentally observed red shift of excitation wavelength on oligomerisation is explained in terms of the change in the HOMO-LUMO energy gap due to complex formation. The impact of dimer formation on the proton magnetic resonance spectrum of serotonin monomer is also examined. ? 2015 Taylor and Francis.
  • Thumbnail Image
    Item
    Polymeric Encapsulates of Essential Oils and Their Constituents: A Review of Preparation Techniques, Characterization, and Sustainable Release Mechanisms
    (Taylor and Francis Inc., 2016) Vishwakarma, G.S.; Gautam, N.; Babu, J.N.; Mittal, S.; Jaitak, Vikas
    Natural polymer based encapsulation of essential oil (EO) is one of the emerging and challenging area of research in perfumery, cosmetics, flavoring agents, preservatives, therapeutics, etc. The knowledge of formulation techniques and physico-chemical properties of the polymers are the basic requirements for the successful encapsulations of essential oils (EOs). This current review article is focused on a comparative account of various formulation techniques based on their applicability. For the first time, it also reviews various physico-chemical techniques used in the analysis of EO encapsulates to determine their stability, structure, surface morphology, and encapsulation efficiency. Further, the mechanisms involved in the release of EOs from encapsulates, along with various factors affecting their release, have also been discussed. ? 2016 Taylor & Francis Group, LLC.