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ThesisItem Embargo Synthesis of boron and phosphorous doped graphene fabricated with magnesium ferrite – bentonite nanocomposite for the remediation of pollutants(Punjab Agricultural University, 2022) Manpreet Kaur; Manpreet KaurGraphene oxide (GO) doped with heteroatoms are gaining interest in depollution of water because of their large surface area. The boron-doped GO (B-GO), phosphorous-doped GO (P-GO) and boron and phosphorous co-doped GO (BPGO) in different w:w ratios were synthesized and fully characterized using analytical techniques viz. FT-IR, XRD, SEM-EDS, TEM, BET, Mössbauer and XPS. In order to impart magnetic features to doped GO materials, magnesium ferrite-bentonite (MGF-B) was used to fabricate nanocomposite of MGF-B and BPGO having hierarchical nanoflowers like morphology (HNFs). TEM of co-doped GO showed more wrinkled surface than doped GO, whereas in case of HNFs, chiffon-like BPGO nanosheets were wrapped on the MGF-B surface, resulting in a porous flower-like morphology. The synthesized materials were explored as adsorbents for the removal of Pb(II) and As(III) ions and as photocatalysts for the degradation of martius yellow, p-nitrophenol and malathion from synthetic waste water. The trend for the percentage removal of heavy metals by adsorption and degradation of organic pollutants by photocatalysis in the descending order was found to be: HNFs > BPGO-1:1 > BPGO-1:5 > BPGO-1:0.2 > MGF-B > P-GO > B-GO > GO. The adsorptive and photocatalytic potential of HNFs was greater as compared to pristine, doped and codoped GO due to high surface area, remarkable charge transfer ability and layered structure of codoped GO sheets. The HNFs possessed appreciable saturation magnetization than doped and co-doped GO layers, which led to its easy separation and reusability. Box-Behnken design was utilized for exploring the simultaneous effects of the independent variables on removal of metal ions and degradation of organic pollutants (as dependent variable) using HNFs. The adsorption and photocatalytic mechanism was proposed on the basis of adsorption isotherm, thermodynamic, kinetic and quenching studies. Enhanced activity of HNFs with adsorption of heavy metal could be defined by the electronic structural properties of elements. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life industrial water matrices.ThesisItem Restricted Evaluation of doped strontium ferrite nanoparticles functionalized with silica, carbon quantum dots and Cl-doped graphene for the removal of contaminants(Punjab Agricultural University, 2022) Grewal, Jaspreet Kaur; Manpreet KaurDoped spinel ferrites and their functionalized nanocomposites with silica (SiO2), carbon quantum dots (CQDs) and chlorine doped graphene oxide (Cl-GO) have attracted immense interest as adsorbents and photocatalysts for water remediation. This work reports the facile strategy for the synthesis and evaluation of Sr1-xTixFe2O4+δ, SiO2, CQDs, Cl-GO and their functionalized nanocomposites for the removal of Cd(II), As(III), p-nitrophenol, pendimethalin and martius yellow from contaminated water. The structural, magnetic, adsorptive and photocatalytic properties were comprehensively studied using different analytical techniques viz. XRD, XPS, FTIR, BET, VSM, TEM, SEM-EDS and 57Mӧssbauer spectroscopy. TEM micrographs revealed the decreased extent of agglomeration in Sr0.4Ti0.6Fe2O4.6 and Sr0.7Ti0.3Fe2O4.3 due to the introduction of non-magnetic Ti4+ ions. TEM image of Sr0.4Ti0.6Fe2O4.6-Cl-GO NC displayed wrinkled nanosheets of Cl-GO containing ferrite NPs with particle size of 25-30 nm distributed over their surface. The fabrication of core-shell nanostructures with SiO2 was clearly visible from their TEM micrographs. The trend for the percentage removal of heavy metals by adsorption and degradation of organic contaminants by photocatalysis in the descending order was found to be: Sr0.4Ti0.6Fe2O4.6-Cl-GO > Sr0.4Ti0.6Fe2O4.6-CQDs > Sr0.4Ti0.6Fe2O4.6@SiO2 > SiO2@Sr0.4Ti0.6Fe2O4.6 > Sr0.4Ti0.6Fe2O4.6. The increased adsorption potential of functionalized nanocomposites as compared to pristine NPs was attributed to the increased surface area, functional moieties, and decreased particle size. The higher photocatalytic efficiency of Sr0.4Ti0.6Fe2O4.6-Cl-GO nanocomposite could be ascribed to the fast charge transfer, stabilization and hindered recombination of electron-hole pairs at the interface of Cl-GO and Sr0.4Ti0.6Fe2O4.6 NPs. Box-Behnken Design (BBD) of response surface methodology was utilized for exploring the simultaneous effects of independent variables on the removal of heavy metal ions and organic pollutants using Sr0.4Ti0.6Fe2O4.6-Cl-GO nanocomposite. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life water matrices.ThesisItem Restricted Synthesis and derivatization of substituted 3,5-dimethoxy-4-hydroxy benzaldehydes and their biological activities(Punjab Agricultural University, Ludhiana, 2021) Sahni, Tanvi; Sharma, SunitaNaturally occurring phenolic aldehyde 3,5-dimethoxy-4-hydroxybenzaldehyde (syringaldehyde) was derivatized to synthesize compounds like Schiff Bases (I-IX), β-lactams (X-XI), azo derivatives (XII-XV), hydrazones of azo derivatives (XVI-XXVII), hydrazones (XXVIII-XXXI), thiosemicarbazones (XXXII- XXXIII), ,β-unsaturated compounds (XXXIV-XXXVIII) and esters (XXXIX-XLIX). Characterization of synthesized compounds was done using UV-visible, FT-IR, 1H and 13C NMR. All the synthesized compounds were evaluated for antioxidant potential i.e. DPPH, FRAP and Phosphomolybdate assay), microbial potential against Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella sp. and Enterobacter sp. and fungicidal potential against four pathogenic fungi of maize against Rhizoctonia solani, Dreschlera maydis, Fusarium verticillioides and Macrophomina phaseolina. In the DPPH assay, syringaldehyde and compounds (VI, VII, XXXVIII and XXXIX) were more effective than standard BHT while none of the compound was more effective than standard ascorbic acid. In FRAP assay, compounds (VII, X, XI, XVIII, XX, XXI, XXII, XXIII, XXIV, XXV, XXVI, XXVII) were effective than ascorbic acid and BHT standards while none of the compound was more effective than ascorbic acid in terms of phosphomolybdate assay. Compounds (VIII, X, XI, XV, XXI, XXIV and XXXIX) were more effective than ampicillin against B. subtilis. Compounds (I, II, III, VI, VIII, IX, X, XI, XII, XIII, XIV, XV, XVIII, XXI, XXII, XXIII, XXIV, XXV, XXVII and XXXIX) showed greater zone of inhibition than ampicillin against P. aeruginosa. Microbial potential at par with ampicillin against E.coli was showed by compounds (VIII, XI, XXI and XXII). Four compounds (XV, XXI, XXII and XXVI) were more effective than ampicillin against Enterobacter sp. while none of compound was found more effective than ampicillin against Klebsiella sp. Antifungal potential of Compound (VI) was found at par with carbendazim 50 WP against R. solani. Mycelial growth of D. maydis was inhibited by fourteen compounds more than carbendazim 50 WP but less than Mancozeb 75 WP. None of the compound was effective than carbendazim 50 WP against F. verticillioides and M. phaseolina.ThesisItem Open Access Evaluation of synthesized ferrite nanocomposites with N-doped graphene and carbon microspheres for the removal of heavy metals and organic pollutants(Punjab Agricultural University, Ludhiana, 2021) Manmeet Kaur; Manpreet KaurMagnetic ferrites and their nanocomposites with nitrogen doped graphene oxide (N-GO) and hollow mesoporous silica have received immense interest as adsorbents and photocatalysts for water decontamination. This work reports facile strategy for the synthesis and evaluation of N-GO, MFe2O4 NPs (M= Mg, Ca), MFe2O4-NGO (M= Mg, Ca) and hollow mesoporousnanocomposites for the removal of Pb(II), Ni(II), As(III), CR dye and PNP from contaminated water.NCs of NGO with MFe2O4 NPs were prepared using ultra sonication method. For dual core shell nanocomposite, hollow mesoporous SiO2 core was synthesized using polyethylene glycol (PEG) and cetyltrimethyl ammonium bromide (CTAB) as cotemplates. Synthesized SiO2 was used as template over which MgFe2O4 NPs were loaded using sodium dodecyl sulphate (SDS) as a surfactant to synthesize MgFe2O4@SiO2 core-shell nanocomposite. This nanocomposite was further loaded with N-GO in order to design NGO@MgFe2O4@SiO2 dual core nanocomposite by ultra sonication method. Structural, magnetic and surface properties of the nanocomposites were analyzed using various physicochemical techniques. The effectiveness of NPs and nanocomposites for the removal of Pb(II), Ni(II) and As(III) and photodegradation of CR and PNP was studied.MgFe2O4@SiO2 displayed maximum heavy metal removal whereas, NGO@MgFe2O4@SiO2 dual corenanocomposite exhibited maximum photocatalytic degradation for organic pollutants. The mechanism of adsorption and photocatalysis from spiked water was investigated by batch experiment studies.The adsorption data was best fitted into Langmuir adsorption isotherm and followed pseudo-second-order kinetic model.The degradation mechanism for CR and PNP was proposed on the basis of mass spectrometric analysis of products formed during photodegradation. Also, the comparative photocatalytic activity of spiked distilled water and contaminated water revealed reduction in photocatalysis of 17% and 22% in the contaminated water. The synthesis of NCs of MgFe2O4 NPs with doped carbon material and core-shell synthesis using SiO2 core provide new synthetic strategy for further modification of pristine ferrite NPs for future applications.ThesisItem Open Access Chemical derivatizations of major constituent of cumin (Cuminum cyminum) and their biological activity(Punjab Agricultural University, Ludhiana, 2021) Pardeep Kaur; Sharma, SunitaCuminum cyminum is an annual herbaceous plant belonging to the family Apiaceae genus Cuminum. In the present study, chemical composition of essential oil and different solvent extracts of cumin of variety GC-4 was determined by GC-MS analysis. Cuminaldehyde was found to be the major constituent present in the essential oil and second major compound present in the different solvent extracts (except chloroform). The proximate analysis of cumin seeds showed that it contains 8.58±0.20, total minerals 8.62±0.05, crude protein 14.43±0.02, crude fibre 11.06±0.01, fats 15.00±0.04, total sugars 2.30±0.21 and total carbohydrates 40.01±0.06. Elemental investigation of cumin seeds showed that it contains micronutrients like Iron: 181.33, copper: 14.25, manganese: 25.75, zinc: 31.25, chromium: 10.15, nickel: 2.38, cobalt: 2.05, cadmium: 2.03, lead: 58.75, arsenic: 118.50 in parts per million concentrations. Phytochemical study revealed that various phytochemicals viz alkaloids, saponins, tannins, coumarins, amino acids, flavonoids, proteins, phenols and carbohydrates were present in different solvent extracts. Aqueous extract of cumin seeds was used as a bioreductant for the synthesis of silver nanoparticles. Different derivatives i.e. Schiff Bases, hydrazones, thiosemicarbazones, chalcones and pyrazolines of major constituent of essential oil namely cuminaldehyde (isolated from essential oil by column chromatography) were synthesized. Characterization of synthesized compounds was done using UV-visible, FT-IR, 1 H and 13C NMR. Essential oil, different solvent extracts, silver nanoparticles, cuminaldehyde and its derivatives were screened for their antioxidant (via DPPH assay), microbial (against Pseudomonas sp., Klebsiella sp. and Enterobacter sp.) and fungicidal potential (against Fusarium wilt, Ascochyta blight and Bortrytis gray mould. Cuminaldehyde derivatives were found more effective as compared to cumin essential oil, its major constituent, different solvent extracts of cumin seeds and silver nanoparticles synthesized from aqueous cumin seed extract.ThesisItem Restricted Regioselective elaboration of isatin and their biological activity studies(Punjab Agricultural University, Ludhiana, 2021) Komalpreet Kaur; Utreja, DivyaRegioselective elaboration of isatin at N-1 and C-3 position were carried out using different reagents. The synthesized isatin derivatives (2a-g and 4a-f) were characterized by 1HNMR, 1 HNMR-D2O, 13CNMR, FT-IR spectroscopies, mass spectrometery and elemental analysis. In vitro biological evaluation of synthesized isatin derivatives as antioxidant, antimicrobial and nematicidal agents had been carried out. The antioxidant evaluation using different models revealed that the compounds 1-decyl-indoline-2,3-dione (2g) and 3-heptyl-3-hydroxyindolin-2-one (4f) exhibited potent antioxidant potential due to the increase of electron donating character. The antimicrobial and nematicidal activity against Pseudomonas aeruginosa, Pseudomonas oryzihabitans, Xanthomonas campestris and Meloidogyne incognita pathogenic organisms revealed that the compounds isatin (1), 1-propyl-indoline-2,3-dione (2a) and 3-ethyl-3-hydroxyindolin-2-one (4a) exhibited potent inhibition potential against these pathogenic organisms as compared to other tested compounds. The in vitro results were further validated through in vivo studies on tomato and in silico studies which revealed that the tested compounds during investigation had shown novel interaction with the target binding sites and resulted in potent biological activity.ThesisItem Restricted Synthesis of hybrid benzimidazoles-metal sulfide nanoformulations as antifungal agents(Punjab Agricultural University, Ludhiana, 2020) Radha Rani; AnjaliThree samples of MS-NSs viz. CuS-NSs, FeS-NSs and MnS-NSs were prepared using sonochemical mediated reaction. Co-precipitation method produced three samples of MSNRs viz. CuS-NRs, FeS-NRs and MnS-NRs in solid form. Statistical analysis of antifungal potential of MS-NPs against phytopathogenic fungi of rice viz. D. oryzae, F. verticillioides, C. lunata and S. oryzae indicated that CuS-NSs exhibited the best antifungal potential. A series of 32 compounds containing benzimidazole and 1,2,4-triazole, in a single molecule, were designed using variety of spacers between the two bioactive moieties. Only four compounds viz. 1, 4, 5 and 8 were chosen for synthesis following the combined criteria of stronger binding to tubulin and lanosterol 14 -demethylase (with docking score -5.9 and - 8.9Kcal/mol, respectively), Lipinski filtrations, FMO approach and Toxtree analysis. Compound 8 (4-(1H-benzo[d]imidazol-2-yl)-2-methoxyphenyl 2-(1H-1, 2, 4-triazol-1- ylamino) acetate) was found to be the best antifungal compound against all the test fungi (ED50 16 μg/ml). U-CuS-NSs underwent in situ surface modification, via organic coating with most active benzimidazolyl-1,2,4-triazole i.e compound 8 to produce their nanohybrid (NH-CuS-8). Comparison of ED50 values led to the conclusion that hybridization of CuS-NSs with compound 8 worked well in enhancing antifungal potential of CuS-NSs against all test fungi. Priming the seeds with solutions of FeS-NSs and MnS-NSs resulted in improved seed health but CuS-NSs had negative impact. Seed treatment evaluation studies revealed great potential of NH-CuS-8 to reduce fungal infection.ThesisItem Open Access Evaluation of synthesized ternary doped ferrite nanoparticles and their graphene oxide composites as enzyme mimics and photocatalysts(Punjab Agricultural University, Ludhiana, 2020) Vibha; Manpreet KaurRole of nanoferrites and their graphene Oxide (GO) composites as enzyme mimics and photocatalysts is a thrust area of research. In the present work, pure and ternary doped ferrite nanoparticles (NPs) of Mn, Co and Cu and their GO nanocomposites (NCs) were synthesized using facile sol-gel and sonication method respectively. FT-IR spectra and XRD patterns confirmed the formation of single phase ferrite NPs, GO sheets and their NC. Maximum saturation magnetization value was 65.0 emu/g for ternary ferrite NPs having formula Mn0.4Co0.4Cu0.2Fe2O4. SEM and TEM micrographs revealed the porous nature and fabrication of ferrite NPs onto GO sheets in the NCs. The larger surface area of NCs as compared to pristine NPs was confirmed by BET studies. Synthesized NPs, GO and NC were evaluated as peroxidase, superoxide dismutase (SOD) and polyphenol oxidase (PPO) enzyme mimics. MnFe2O4 NPs exhibited maximum peroxidase and PPO mimic activity, whereas SOD mumic activity was shown by CuFe2O4 NPs. Observed results were explained on the basis of structure of ferrite NPs. Synergistic adsorption and photocatalytic potential of ferrite NPs, GO and NC was studied using malachite green and methylene blue as model compounds. The adsorption data was best fitted into Langmuir adsorption isotherm and followed pseudosecond- order kinetic model. The NC exhibited better adsorption and photocatalytic activity as compared to ferrite NPs under visible light. The degradation mechanism was proposed on the basis of mass spectrometric analysis of products formed during photodegradation.
