Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
3 results
Search Results
Item Fluorometric detection of bisphenol A using ?-cyclodextrin-functionalized ZnO QDs(Springer Science and Business Media Deutschland GmbH, 2021) Kadam, V.V.; Mohan Balakrishnan, R.M.; JagadeeshBabu, J.The estrogenic property of bisphenol A (BPA) leads to potential adverse health and ecological effects. A simple, selective, and cost-effective sensor capable of detecting BPA would have a noteworthy relevance for the environmental system. The present work illustrates the synthesis and characterization of ?-cyclodextrin (?-CD) functionalized zinc oxide (ZnO) quantum dots (QDs) for the selective detection of BPA. BPA has a fluorescence quenching effect on functionalized ZnO QDs, and the decrease in fluorescence intensity is associated with the BPA concentration between 2 and 10 ?M. Under the optimum reaction condition, a good linear correlation was obtained between relative fluorescence-quenching intensity of ?-cyclodextrin-functionalized ZnO QDs and BPA concentration (R2 = 0.9891). The lower detection limit of functionalized QDs for BPA was estimated to be 0.19 ?M, which is lower than the toxic limits in aquatic biota. The fluorescence-based detection of BPA may be ascribed to the electron transfer mechanism, which is elucidated with scientific details from the literature. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.Item Photocatalytic degradation of diclofenac using TiO2-CdS heterojunction catalysts under visible light irradiation(Springer Science and Business Media Deutschland GmbH, 2021) Mugunthan, M.; Bharathaiyengar, S.M.; JagadeeshBabu, J.The present study reports the photocatalytic degradation of analgesic drug diclofenac using the hydrothermally prepared TiO2-CdS heterojunction catalyst. The results suggest that the prepared catalysts exhibited excellent photocatalytic activity under visible light irradiation. The photodegradation kinetics were well fitted to the pseudo-first-order reaction. The apparent reaction rate constant for TC5 catalyst in the diclofenac degradation was 0.02316 min?1. Mineralisation of diclofenac using TC5 photocatalyst was around 86% within 4 h of irradiation time. The operating parameters such as optimal catalyst dosage, apparent solution pH and the effect of initial diclofenac concentration were also studied using the TC5 catalyst. The role of active species in the degradation mechanism was elucidated and it was found that the hydroxyl radical is the main active species in the diclofenac degradation mechanism. The charge transfer between heterojunction catalysts is facilitated by direct Z-scheme heterojunction structure. The coupled photocatalysts also showed good photochemical stability and reusability over five successive reaction cycles. The tentative degradation pathway has been devised based on LC-MS peaks, and it is found that only m/z 224, m/z 178 and m/z 124 were persisted at the end of the reaction. © 2021, Springer-Verlag GmbH Germany, part of Springer Nature.Item Zinc-decorated barium oxide nanorods for the effective sunlight-induced catalytic degradation of Irgalite violet dye(Springer Science and Business Media Deutschland GmbH, 2023) Ilango, I.; Susanna, D.; Gabriella, R.; Mohan Balakrishnan, R.M.; JagadeeshBabu, J.Simple and facile fabrication of barium oxide (BaO) and zinc-decorated barium oxide (ZnBaO) nanocatalysts was accomplished through a co-precipitation technique. Irgalite violet (IV) dye was subjected to sunlight-induced catalytic degradation using novel catalyst ZnBaO nanorods. The synthesized nanocatalysts were subjected to various analytical techniques, including FE-SEM/EDX, XRD and FTIR, for their comprehensive characterization. X-ray diffraction confirmed the crystallinity of BaO and ZnBaO nanocatalysts. The FE-SEM image of the ZnBaO nanocatalyst revealed the occurrence of distinct nanorods with a mean size of 22.5 nm possessing an aspect ratio of 4.95. A characteristic UV absorbance peak was observed at 310 nm for BaO and 380 nm for ZnBaO nanocatalysts. The substitution of Zn to BaO led to a favorable decrease in the band gap energy from 5.315 eV (BaO) to 2.6 eV (ZnBaO). The synthesized BaO and ZnBaO nanocatalysts were used in parametric studies by varying catalyst dosage, irradiation time, pH and initial dye concentration. The ZnBaO nanorods showed a maximum degradation efficiency of 99.9% at pH 11 with a catalyst dosage of 40 mg/50 mL containing 5 mg/L dye concentration. The recyclability studies showed that the ZnBaO nanorods could serve as a potential catalyst for degrading dyes. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.