Materials Science, Polymers and Plastics, Metals and Alloys, Catalysis
7
Scopus Publications
Scopus Publications
Optical Sensing and Photocatalytic Dye Degradation Using Blue-Luminescent Graphene Quantum Dots Sirigere Chandraiah Sharath, Vismitha S. Patil, B. Maheshkumar, Muttanagoud N. Kalasad Particle and Particle Systems Characterization, 2026 Colloidal graphene quantum dots (GQDs) are synthesized via a pyrolysis method using air‐stable hydrazine hydrate. The optical and structural properties of GQDs are investigated by optical absorption, photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). The colloidal GQDs are blue luminescent with defect free amorphous structure, indicating the formation of high‐quality GQDs. The average estimated size of the GQDs is 2.2 nm with a uniform particle size distribution from TEM measurement. The colloidal GQDs are employed as an optical sensor for the detection of L‐cysteine based on the PL spectra and exhibit an effective and selective response within the linear range of 10–200 µM, estimated detection limit of 7.64 µM. Additionally, the photocatalytic performance of the GQDs is evaluated through the degradation of Rhodamine B (RhB) and Methylene Blue (MB) under mercury vapor lamp irradiation. The photodegradation efficiencies for RhB and MB are 82.36% and 60.90%, respectively, at 210 min, highlighting their potential as efficient photocatalysts. These findings demonstrate the multifunctionality of GQDs in both optical sensing and environmental remediation applications.
Synthesis and characterization of silver nanoparticles for photocatalytic application B. Maheshkumar, Vismitha S. Patil, G. H. Nagaveni, Raghu M. Gunnagol, M. A. Gadyal, M. N. Kalasad Hybrid Advances, 2025 Metal nanocrystals have gained immense significance due to their unique physical, chemical and biological properties and widely used for catalysis, drug delivery, water purification, solar cells etc. In this study, synthesis of silver (Ag) nanoparticles by chemical precipitation method using thioglycolic acid (TGA) as a capping molecule. The size of the Ag nanoparticles 17–23 nm is controlled by varying the concentration of reducing agent. Optical and structural properties of the Ag nanoparticles are systematically characterized using optical absorption spectroscopy, photoluminescence spectroscopy, FTIR, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR analysis confirms the effective surface passivation of Ag nanoparticles by thiol molecules, while XRD patterns reveal face-centred cubic (fcc) crystal structure. The synthesized Ag nanoparticles served as potential catalyst in photocatalysis of an organic dye. The nanoparticles exhibit 92 % of degradation efficiency within 200 min towards the model pollutant methyl orange (MO) dye under mercury vapor lamp irradiation.
Optical and electrical properties of amine functionalized CeO2 nanoparticles G.H. Nagaveni, B. Maheshkumar, S.V. Halse, M.N. Kalasad Chemical Physics Impact, 2024 Herein, we report the synthesis of cerium oxide (CeO2) nanoparticles using oleylamine as capping molecule. The method is simple and economical permits to control the desired particle size used for optoelectronic applications. By varying the cerium ion concentration, CeO2 nanoparticles of different particle sizes were synthesized. The optical and electrical conductivity properties were studied by optical absorption and photoluminescence measurements. The structural properties of the CeO2 nanoparticles were studied using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The CeO2 nanoparticles exhibit fluorite cubic phase and the particles are in spherical shape, the estimated average particle size ranges from 2 – 7 nm. The calculated optical and electrical conductivity for sample C4 is σopt = 4.325 х 1010 S−1Cm−1 and σele = 1.6 х 1012 S/m respectively. The idiosyncratic feature of the Ce4+ ions with attached amine group shows the positive optical conducting behavior of CeO2 nanoparticles. The present results symbolize that the amine groups are proficient to bring out positive results of optical parameters that holds promise for developing novel devices.
Metal oxide nanocrystals—applications Vismitha S. Patil, N.I. Sattigeri, B. Maheshkumar, G.H. Nagaveni, S.V. Halse, M. Shashank, S.R. Inamdar, M.N. Kalasad Handbook of Emerging Materials for Sustainable Energy, 2024
Experimental characterization of surface modified Palmyra Palm Leaf Stalk Fiber (PPLSF) /polymer composites– Mechanical, Crystallinity and Acoustic properties D Shanmugam, Rama Thirumurugan, M Thiruchitrambalam, B Maheshkumar Journal of Natural Fibers, 2022 In this work chemically treated Palmyra Palm Leaf Stalk Fiber (PPLSF) reinforced polymer composites are evaluated for their mechanical properties (Tensile, Flexural, and Impact) before and after Moisture absorption, crystallinity, and acoustic properties for their possible usage in engineering applications. Alkali and silane treated PPLSF are used as reinforcements in the polyester matrix for fabrication of composite samples. The composite specimens were soaked in three types of water (drinking water, well water and sea water) for a period of 3 days and tests on the specimens were conducted after each day of immersion at different time intervals. It was observed that there was less moisture abortion was less in silane treated composites. Mechanical and acoustic tests showed that the properties of silane treated fiber composites were higher compared to all the other composites. Moisture penetration was higher in the composites exposed to sea water in comparison to others. The changes in the crystallinity index of the composites were identified through X-Ray Diffraction (XRD) technique. Scanning Electron Microscopy (SEM) images of the tensile fractured specimens were used to understand the mechanism of failure of the composites before and after moisture absorption. Properties of the composites from the literature were compared with those of the proposed composite.