http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/4 2026-04-07T15:00:43Z 2026-04-07T15:00:43Z Aravind, Anu Mini Tomy, Merin Kuttapan, Anupama Aippunny, Ann Mary Kakkassery Suryabai, Xavier Thankappan http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/425 2025-01-30T04:46:11Z 2023-11-14T00:00:00Z

Progress of 2D MXene as an Electrode Architecture for Advanced Supercapacitors: A Comprehensive Review Aravind, Anu Mini; Tomy, Merin; Kuttapan, Anupama; Aippunny, Ann Mary Kakkassery; Suryabai, Xavier Thankappan Supercapacitors, designed to store more energy and be proficient in accumulatingmore energy than conventional batteries with numerous charge−discharge cycles, have beendeveloped in response to the growing demand for energy. Transition metal carbides/nitrides calledMXenes have been the focus of researchers’ cutting-edge research in energy storage. The 2D-layeredMXenes are a hopeful contender for the electrode material due to their unique properties, such ashigh conductivity, hydrophilicity, tunable surface functional groups, better mechanical properties, andoutstanding electrochemical performance. This newly developed pseudocapacitive substance benefitselectrochemical energy storage because it is rich in interlayer ion diffusion pathways and ion storagesites. Making MXene involves etching the MAX phase precursor with suitable etchants, but differentetching methods have distinct effects on the morphology and electrochemical properties. It is anoverview of the recent progress of MXene and its structure, synthesis, and unique properties. There isa strong emphasis on the effects of shape, size, electrode design, electrolyte behavior, and othervariables on the charge storage mechanism and electrochemical performance of MXene-basedsupercapacitors. The electrochemical application of MXene and the remarkable research achievements in MXene-based compositesare an intense focus. Finally, in light of further research and potential applications, the challenges and future perspectives thatMXenes face and the prospects that MXenes present have been highlighted.

2023-11-14T00:00:00Z Ann Mary, K A Paul, Tessy Kuttappan, Anupama Jibin, P O Anoop, K K http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/402 2025-01-20T09:18:17Z 2023-12-01T00:00:00Z

Dual emitting carbon nanoparticles for tunable white light emission Ann Mary, K A; Paul, Tessy; Kuttappan, Anupama; Jibin, P O; Anoop, K K Eco-friendly, biomass derived single component luminescent materials with dual emission bands hold immense potential in white light emitting devices (WLED). Compared to WLED fabricated from different color emitting carbon nanoparticles, self-reabsorption and degradation will be negligible in single system white light emitting materials which guarantees stability in long run. Herein, we report a facile, inexpensive and sustainable direct thermal decomposition method to synthesize carbon nanoparticles with dual emission bands. Addition of PVP could efficiently enhance the red emission band of carbon nanoparticles. The excitation dependent broad blue-green emission and excitation independent narrow red emission helps to obtain white light emitting carbon nanoparticles. Upon change in excitation wavelength from 410 nm to 370 nm, white light emissions are obtained with tunable CCT value from 2648 K to 8980 K respectively. By virtue of this tunable warm to cool white light emission, single system WLED can be designed suitable for both indoor and outdoor applications.

2023-12-01T00:00:00Z Paul, Tessy Anupama, K Jibin, PO Ann Mary, KA http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/187 2022-03-03T10:05:16Z 2020-01-01T00:00:00Z

Spectroscopic investigations on Se/RE doped sol gel derived silica matrices Paul, Tessy; Anupama, K; Jibin, PO; Ann Mary, KA Selenium and rare earth ions co-doped inorganic luminescence silica matrices are synthesized through sol gel route. The incorporation of cubic Se quantum dots within the porous silica frame is confirmed from TEM analysis. The successful entrapment of green as well as blue color emitters within the silica frame generates evident luminescence bands in the visible region. Obtained Se/Tb3+ ions doped silica glasses give characteristic sharp emission peaks of terbium ions at 488 nm, 543 nm, 584 nm, 619 nm wavelength under UV excitations. A broad blue emission band from selenium nanodots centered at 421 nm wavelength is observed in the emission spectrum. Colorimetric studies are done with the aid of 1931 chromaticity diagram. CIE indices of the co-doped glasses are found to lie in between the CIE indices of selenium doped silica glasses (0.18, 0.21) and terbium doped silica glasses (0.28, 0.46). For a fixed concentration of Se and terbium in silica glasses, tunable luminescence without shift in peak wavelength is observed under the excitation wavelength of 340 nm to 380 nm. Varying blue to green luminescence intensity ratio (B/G) with the excitation wavelength reveals the possibility of tunable emission of the glassy matrix for their applicability in solid lighting systems.

2020-01-01T00:00:00Z A, Ann Mary K Mary, EJ Sonia Vidyadharan, Viji Philip, Reji V, Unnikrishnan N http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/139 2022-03-03T07:11:21Z 2015-02-01T00:00:00Z

Thermo-optic nonlinearity of the laser dye LDS 867 under low power CW laser excitation A, Ann Mary K; Mary, EJ Sonia; Vidyadharan, Viji; Philip, Reji; V, Unnikrishnan N Thermally induced optical nonlinearity of the laser dye LDS 867 is studied in ethanol solution using the self phase modulation and closed aperture z-scan techniques, employing a continuous wave low power He-Ne laser beam for excitation. The nonlinear optical (NLO) coefficients are obtained by analyzing the z-scan curve on the basis of the thermal lens model. The dye exhibits a negative thermal nonlinearity which can be inferred from the occurrence of a pre-focal peak followed by a post-focal valley in the z-scan. The large nonlinear refractive index (n2) measured at the excitation wavelength of 633nm reveals that the material is NLO active even at low excitation powers of less than 1 mW. Results indicate that LDS 867 is a promising material for optical power limiting applications.

2015-02-01T00:00:00Z