Faculty Publications
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Item Adsorption of pharmaceuticals pollutants, Ibuprofen, Acetaminophen, and Streptomycin from the aqueous phase using amine functionalized superparamagnetic silica nanocomposite(Elsevier Ltd, 2021) Chandrashekar Kollarahithlu, S.; Mohan Balakrishnan, R.M.Pharmaceuticals are one of the emerging pollutants that pose a severe threat to the aquatic habitats, which in turn affects other species in the biosphere. The superparamagnetic based silica nanocomposites modified with aminosilane were characterized for their physicochemical properties and also the purity of the nanocomposite obtained was determined. The adsorptive properties of the nanocomposites were investigated for the removal of pharmaceutical pollutants such as Ibuprofen, Acetaminophen, and Streptomycin from aqueous solutions. The adsorption process of pharmaceuticals was found to reach equilibrium within the first 15 min reporting high removal efficiency of up to 97% for Ibuprofen (IBF) followed by (94%) acetaminophen (ACE) and (70%) streptomycin (STR) for a concentration of 12 mg L?1. The adsorption process was found to follow the pseudo-second-order kinetics and fits well with the Langmuir isotherm model, confirming the adsorption on to the homogenous surface of the nanocomposite. The amine functional groups formed on the nickel ferrite nanocomposites by coating aminopropyltrimethoxysilane (APTS) were observed to aid the adsorption process. The adsorption capacity of the nanocomposites varies for IBF, ACE, and STR as 59, 58, and 49 mg g?1 at pH 7.0, 6.0, and 5.0, respectively. The amine coated magnetic nanocomposite also showed excellent regeneration capacity for up to four cycles and can be a promising adsorbent, especially for removing of pharmaceutical pollutants from aqueous streams. © 2021 Elsevier LtdItem Photocatalytic degradation of ciprofloxacin & norfloxacin and disinfection studies under solar light using boron & cerium doped TiO2 catalysts synthesized by green EDTA-citrate method(Elsevier B.V., 2021) Manjunatha, M.; Chandewar, P.R.; Mahalingam, H.The presence of antibiotic residues in water bodies is an emerging global concern due to its potential development of antimicrobial resistance. Hence, it is essential to develop photocatalysts that not only degrade the antibiotics but can also simultaneously disinfect. Four different boron and cerium doped TiO2 photocatalysts, synthesized by the EDTA-citrate method, are studied for the degradation of two common fluoroquinolone-based antibiotics: ciprofloxacin (CIP) and norfloxacin (NOR) under sunlight. The catalysts are characterized by SEM, TEM, Raman spectroscopy, XPS, DRS, BET surface area and particle size analyzer. At optimized conditions, the synthesized catalysts showed 90–93% degradation for both CIP and NOR. The effects of catalyst loading and initial concentration are studied, and the reaction is found to be pseudo-first-order. The degradation is analyzed by COD reduction and LC–MS, and the by-products of degradation determined. The recycle studies showed that the catalysts are stable up to three consecutive runs. The scavenging experiments indicated e? and OH? as the dominant species responsible for the photocatalytic activity. The disinfection studies using these catalysts under solar light gave 95–99.99% efficiency for E.coli confirming that they are very efficient and can be further exploited for large scale treatment. © 2020 Elsevier B.V.Item Exploring the Synergy of B, Ce Dopants in Codoped Titanium Dioxide Multifunctional Photocatalysts for Antibiotic Degradation and Microbial Disinfection Under Solar Light(John Wiley and Sons Inc, 2022) Manjunatha, M.; Chandewar, P.R.; Mahalingam, H.An eco-friendly, controllable citrate-EDTA complexing sol–gel method is employed to systematically synthesize a series of BxCe1−xTiO2 (x = 0.9, 0.8, 0.7 at%) codoped photocatalysts. The degradation of ciprofloxacin (CIP) and norfloxacin (NOR) antibiotics, as well as Escherichia coli disinfection under sunlight, is assessed using these synthesized codoped photocatalysts. After physicochemical characterization of the synthesized catalysts for particle size, surface area, morphology, crystal structure, surface chemistry, bandgap energy values, and recombination, it is evident that the codoping has improved the visible light absorption, reduced the recombination, and promoted higher crystallinity as well as anatase phase content. The codoped catalysts also demonstrate an enhanced photocatalytic activity under solar light with regard to the degradation of the chosen antibiotics when compared to the performance of the monodoped counterparts or the latest generation catalysts from the literature. The highest degradation performance (≈98%) is shown by B0.8Ce0.2TiO2 in the case of CIP and B0.9Ce0.1TiO2 in the case of NOR. Also, in the case of microbial disinfection, these codoped catalysts are much better (by a factor of ≈10) than that of the monodoped catalysts. © 2021 Wiley-VCH GmbH.Item A chemically robust amine-grafted Zn(ii)-based smart supramolecular gel as a regenerative platform for trace discrimination of nitro-antibiotics and assorted environmental toxins(Royal Society of Chemistry, 2023) Saha, E.; Chhetri, A.; Venugopal, P.P.; Chakraborty, D.; Mitra, J.Smart supramolecular metallogels are fascinating reusable materials with the potential for a wide range of sustainable applications including the detection of multiple lethal pollutants. We have assembled a chemically robust triazole-containing Zn(ii)-supramolecular gel (ZnGel), where the channels and surface of the gel are strategically decorated with triazole N and appended -NH2 units that are pivotal to ZnGel's efficacy as a multi-sensory probe. ZnGel shows selective fluorescence quenching in the presence of traces of nitro-antibiotics (LOD of nitrofurantoin: 4.62 ppm) and electron-deficient nitrophenols (LOD of 4-nitrophenol: 4.18 ppm), without any prior activation. Density functional theory calculations delineate the importance of the triazole gelator in the turn-off fluorescence response of ZnGel to divergent organo-toxins and substantiate the supramolecular interactions between the ZnGel and the analytes. Significant fluorescence quenching of ZnGel ensued in the presence of a trace amount of Fe3+ (LOD: 6.13 ppm) over other competing metal ions, in addition to visible colorimetric changes in the ZnGel upon metal encapsulation. The quenching ability of ZnGel remains unaltered for multiple cycles toward these environmental pollutants. The noteworthy quenching efficiency is attributed to a combination of static and dynamic fluorescence quenching and resonance energy transfer, which are in harmony with the DFT predictions. Thus, ZnGel provides a platform for the development of gel-based probes for diverse applications in the future. © 2023 The Royal Society of Chemistry.Item Adsorption of selective fluoroquinolones by cysteine modified silane magnetic nanocomposite from the aqueous phase(Institute for Ionics, 2023) Senathiraja, T.; Lolla, S.A.; Singh, Y.; Kollarahithlu, S.C.; Mohan Balakrishnan, R.M.Elevated levels of pharmaceutical pollutants in the aquatic environment have caused detrimental effects on water quality and biodiversity. Nanomaterials are among the most promising technologies to detect, adsorb, and remove these pollutants from the aqueous systems. The current work explores the applicability of nickel ferrite nanocomposite functionalized with L-cysteine attached 3-glycidyloxypropyltrimethoxysilane to remove a selective class of antibiotics known as fluoroquinolones (Lomefloxacin, Ciprofloxacin, and Norfloxacin). 20 mg of this nanocomposite achieve maximum removal efficiencies of 61%, 67%, and 75% for 40 mg L−1 of lomefloxacin, norfloxacin, and ciprofloxacin, respectively. The nanocomposites also show good regeneration capacity with negligible reduction in the efficiencies up to three cycles. Furthermore, adsorption isotherms such as Langmuir and Freundlich isotherms were used to characterize the removal of fluoroquinolones from the aqueous phase by the nanocomposites. The results show that the adsorption process was in good agreement with the Langmuir isotherm, thus confirming its monolayer sorption process and also reveals that adsorption kinetics follows a pseudo-second-order model. The maximum adsorption capacity of functionalized nickel ferrite nanocomposites are 122 mg g−1, 135 mg g−1, and 150 mg g−1 for lomefloxacin, norfloxacin, and ciprofloxacin, respectively. Overall, all the results obtained indicate that the nickel ferrite nanocomposite functionalized with L-cysteine attached 3-glycidyloxypropyltrimethoxysilane is an effective adsorbent to remove fluoroquinolones from the aqueous systems and could be potentially incorporated in water treatment processes under well-defined parameters. © 2022, The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University.Item Amino acid functionalized metal oxide nanocomposite for the removal of fluoroquinolones(Elsevier Ltd, 2023) Ilango, I.; Mohan Balakrishnan, R.M.Antibiotic consumption has increased globally, and its discharge into water bodies at concentrations ranging from a few ng/L to mg/L has a detrimental effect on the ecosystems. Amino acid functionalized nickel ferrite nanoparticles were chosen to improve the stability of bare nanoparticles and prevent oxidation and leaching ions in nanoparticles thereby targeting the antibiotics in the contaminated water bodies. The removal of ciprofloxacin and lomefloxacin hydrochloride in the aqueous phase was investigated using a hydrothermally synthesized L-Leucine functionalized nickel ferrite nanocomposite (NFO@L). Various analytical techniques were used to analyze L-Leucine functionalized nickel ferrite, and the nanocomposite's average particle diameter was determined to be between 11 and 15 nm. The maximal measured zeta potential was −21.5 mV. Fourier transform infrared spectroscopy (FTIR), ninhydrin assay and X-ray diffraction (XRD) analysis confirmed the attachment of L-Leucine onto nickel ferrite. The nanocomposite's surface-to-volume ratio was calculated to be 92.916 m2/g. The S-shaped curve from the vibrating sample magnetometer analysis reflected the superparamagnetic behaviour of the nanocomposite with a saturation magnetization of 0.665 emu/g. Various parametric experiments were conducted, in which 93.549% ciprofloxacin was removed in 120 min at 303 K, pH 8 and NFO@L dosage of 100 mg in 100 mL whereas 75.192% lomefloxacin hydrochloride was removed in 140 min at 333 K, pH 9 and NFO@L dosage of 70 mg in 100 mL. The plot of experimental datum in kinetic and isotherm studies fitted well with the Pseudo second order kinetic model and Langmuir isotherm. There was no evidence of iron ions leaching from the final analyte. The recycle and regeneration studies showed good stability with a small reduction after four cycle runs. Based on these findings, the Leucine functionalized nickel ferrite nanocomposite could be a potent adsorbent for the removal of low-concentrated ciprofloxacin and lomefloxacin hydrochloride in the wastewater. © 2023Item Defect-mediated time-efficient photocatalytic degradation of methylene blue and ciprofloxacin using tungsten-incorporated ternary perovskite BaSnO3 nanoparticles(Elsevier Ltd, 2024) Jayavelu, Y.; Maharana, G.; Rajender, G.; Reddivari, R.; Divyadharshini, S.; Baby, B.H.; Kovendhan, M.; Fernandes, J.M.; Joseph, D.P.Photocatalytic water purification has been extensively explored for its economic, eco-friendly, and sustainable aspects. In this study, tungsten (W) incorporated BaSn1-xWxO3 (x = 0 to 0.05) nanoparticles synthesized by facile hydrogen peroxide precipitation route has been demonstrated for photocatalytic degradation of methylene blue (MB) dye and ciprofloxacin (CIP) antibiotic. The structural analysis indicates the presence of hybrid composite-like nanostructures with reduced crystallinity. Optical studies reveal blueshift in bandgap and decrease in oxygen vacancy defects upon W-incorporation. Pure BaSnO3 shows overall enhanced photocatalytic activity towards MB (90.22%) and CIP (78.12%) after 240 min of white LED light and sunlight irradiation respectively. The 2 % W-incorporated BaSnO3 shows superior photocatalytic degradation of MB (26.89%) and CIP (45.14%) within first 30 min of irradiation confirming the presence of W to be beneficial in the process. The free radical study revealed the dominant role of reactive hole (h+) and oxygen radical (O2•−) species during photodegradation and their intermediates are investigated to elucidate the degradation mechanism of MB within 30 min of irradiation. This study is promising towards developing defect mediated and time-efficient photocatalysts for environmental remediation. © 2024 Elsevier LtdItem Synthesis and characteristics of Fe/Ni/Cr oxide nanoparticles/PLA hybrid composite coatings on Mg–Zn–Ca alloy(Elsevier Editora Ltda, 2025) Kumar, P.; Kudva S, A.; T, A.; S, R.; Ramesh, M.R.; Prabhu, A.; Anne, G.Biodegradable materials research is dominated by magnesium and alloys thereof due to their excellent compatibility with biological barriers and biomechanical strength. Despite this, the rapid degradation of these materials in the physiological environment is the primary obstacle hindering their utilization in biomedical applications. This issue must be resolved before considering their use in clinical applications. To improve resistance towards corrosion and enhance biological efficacy and compatibility, the surfaces were coated with polylactic acid (PLA) using dip-coating. In this study, iron (Fe), nickel (Ni), and chromium (Cr) oxide nanoparticles from the Coleus amboinicus extract are synthesized and mixed with PLA to develop hybrid composite coatings, which are then applied onto the Mg–4Zn–1Ca alloy. Coleus amboinicus is known for its various medicinal properties, including immunoregulatory effects, antimicrobial activity, anti-inflammatory properties, and potential use in treating sepsis and other ailments. The extracted FeNiCr was used the develop composite coatings on Mg–4Zn–1Ca alloy. The coating improves biocompatibility, antibacterial properties, and overall performance of biomedical implants. These composite coatings were evaluated for their morphological and optical characteristics using a scanning electron microscope (SEM), 3-D non-contact profilometer, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The corrosion characteristics of developed samples were measured by electrochemical corrosion in standard simulation body fluid (SBF) at 37 °C. Furthermore, cytocompatibility of the PLA hybrid composites on osteoblast cells and apoptosis detection using acridine orange-ethidium bromide. Our developed coating showed ratings of 5B and 4B were obtained for FeNiCr/PLA NC- ball burnished (BB) Mg and FeNiCr/PLA nano composite (NC)–Mg samples, respectively, demonstrating the exceptional coating strength and the substrate. The corrosion rate of the FeNiCr/PLA NC-BB-Mg sample (0.02890 mm/y) is two-fold times increased against comparison with the H Mg sample (0.00012 mm/y). Cytocompatibility indicates their cytocompatibility for bone implant applications. © 2025 The AuthorsItem High performance 2D molybdenum MXene polyphenylsulfone membranes for boosting water flux and efficient removal of humic acid, antibiotic and dyes from wastewater(Elsevier B.V., 2025) Satishkumar, P.; Isloor, A.M.; Farnood, R.MXene, a leading two-dimensional material, is attracting scientists due to its rich polar surface termination and compatibility. Through the etching of an aluminum layer from Mo3AlC2, we have effectively produced molybdenum MXene Mo3C2Tx (where T stands for polar moieties like –OH and ?F) and used it to fabricate a new Mo3C2Tx embedded mixed matrix membrane. By the incorporation of highly hydrophilic Mo3C2Tx MXene into polyphenylsulfone (PPSU) membrane, its water flux tremendously increased to a peak value of 290 L m-2h?1 and is higher than 300 % compared to pristine polyphenylsulfone membrane without Mo3C2Tx MXene. Water contact angle study of Mo3C2Tx MXene embedded membranes showed improvement in hydrophilicity with an increase in its loading. Mo3C2Tx-PPSU membrane demonstrated appreciable antifouling nature and pollutant separation efficacy. The optimal membrane revealed 98.68 %, 96.7 %, 84.72 %, and 80.2 % removal of toxic contaminants like humic acid, RB 5 dye, RO 16 dye, and tetracycline antibiotic, respectively. This study offers a novel Mo3C2Tx embedded polyphenylsulfone membrane for wastewater treatment that eliminates potentially harmful humic acid, antibiotics, and dyes. © 2025Item Stimulation of peroxymonosulfate using nickel ferrite nanoparticles for the degradation of Lomefloxacin hydrochloride and caffeine(Springer Science and Business Media Deutschland GmbH, 2025) Ilango, I.; Mohan Balakrishnan, R.; Visvanathan, C.; Bui, X.-T.Lomefloxacin Hydrochloride (LFH), an antibacterial agent, and caffeine (CAF), a cognitive enhancer, are excreted by humans and end up in municipal sewage effluents and surface waters. This pharmaceutical concentration in bodies of water/treatment plants poses a serious threat to both aquatic habitats and humans. A laboratory batch study on the degradation of LFH, CAF and LC (CAF and LFH mixed solution) was carried out using NFO nanoparticles to stimulate potassium peroxymonosulfate (PMS). The NFO nanoparticles were synthesized through a co-precipitation method and characterised using FTIR, XRD, FESEM/EDX, TGA/DTA/DTG, BET, AFM, VSM, and Zeta potential. The particle size distribution from FESEM (using ImageJ software) revealed that 83.3% of particles are ? 100 nm, its mean and standard deviation were estimated to be 43.87 nm and 20 to 25 nm. The NFO nanoparticles’ specific surface area was estimated to be 112.02 m2/g, and the magnetic properties of the NFO nanoparticles were investigated using VSM analysis. The parametric study included bare NFO, PMS without catalyst, pH, catalyst dosage, PMS variation with optimized catalyst, initial concentration of LFH and CAF, and reaction time, with nearly 94.34% LFH was degraded in 220 min, 100% CAF was degraded in 80 min, 78.07% LC was degraded in 40 min. The degraded compounds m/z of LFH, CAF and LC were identified using LC–MS. The recycling and regeneration of NFO nanoparticles were investigated to determine the stability of the NFO nanoparticles in the degradation of LFH and CAF in which the degradation efficiency decreased to 90.68% and 64.1% respectively upon the third wash with distilled water. As a result, the NiFe2O4/PMS system showed improved degradation even after three recycle runs, making it an efficient and economical system for degrading LFH, CAF and even to multi-pharmaceutical pollutants. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.