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Clay mineral obtained from Tuticorin in Tamilnadu, India (Indian Clay- IC) was purified and used to synthesise polyaniline-Indian clay nanocomposites (Pani-IC NCP) by polymerising aniline with the clay by chemical oxidation method using potassium perdisulphate as oxidant and by varying the aniline to clay ratio. The formation of composite in nanoscale was confirmed by XRD and TEM analysis. The in situ intercalative polymerization of monomer within the clays was ascertained by FTIR, UV–visible, XRD, SEM and TEM studies. The analyses of UV visible and FTIR spectroscopy demonstrated that aniline has been polymerized to Pani in its conducting emeraldine form. The conformation adopted by Pani Chains in the clay interlayer depended on the molar ratio of aniline to clay. SEM analysis showed the variation in morphology from granular agglomerate to layered flaky structure as the clay concentration was increased. Thermal stability of the nanocomposites was studied using TGA/DTA and DSC studies and it was found that they showed better thermal stability than their pristine polymers indicating the enhanced barrier property of the nanoclay. XRD showed that the clay host used accommodates higher amount of emeraldine salt than MMT. The Cyclic voltammetry studies of the synthesized nanocomposites showed the one with 0.5 g clay showed better electrochemical response. It exhibited good adherent behaviour on electrode surface at pH 1.0 with two oxidation peaks at 463 and 672 mV and two reduction peaks at 360 and 126 mV. By varying the atmosphere it was found that the nanocomposite modified electrode exhibited oxygen reducing capacity than their Bentonite counterpart. Chronoamperometric and Chronocoulometric studies were also carried out at inert as well as oxidising atmosphere which confirmed the above fact. EIS studies of the modified electrodes showed double layer capacitance value of 5.95 × 10−8 Fcm−2 with the bode phase angle of 70°.

Co-polymer of poly (3-methylthiophene -co- 3, 4-ethylenedioxythiophene) (PMT-co-EDOT) can be synthesized by electrochemical method using the basic monomers such as acetonitrile/tertiary butyl ammonium perchlorate medium. The electrosynthesized co-polymer was characterized like FT-IR, UV–visible, XRD, SEM-EDS analysis and AFM technique. The spectroelectro electrochromic properties of the co-polymer were characterized through UV-transmittance spectra coupled with cyclic voltammetry (CV). From the spectro electrochemical measurement, the coloration efficiency was 685 cm2/C and the optical contrast (Δ%T) was 84 at the wavelength of 420 nm were calculated. The polymer films were displayed multicolour electrochromism. This co-polymer system is applicable as electrochromic devices.

Poly (o-toluidine) (PoT) was synthesised by chemical polymerization method using ammonium persulphate as oxidizing agent. The para disubstituted aromatic rings band at 813 cm−1, indicating the polymer formation was confirmed by Fourier transform infrared spectroscopy (FTIR). The characterization of the polymer amorphous crystalline form was carried out using X-ray diffraction method (XRD). Scanning electron microscope (SEM) image showed uniformly distributed fibrous spongy like morphology. A thermal property of the polymer was evaluated by thermo gravimetric analysis (TGA). Electrochemical characterization studies were carried out to compare the improved performance of PoT modified GCE (PoT/GCE) in optimum pH1.0 under different atmospheric condition by cyclic voltammetry (CV). It was proved that the nitrogen atmosphere enhanced the electrocatalytic activity toward methanol reduction as indicated by the increased reduction peak current in linear sweep voltammetry (LSV). It has been observed that PoT/GCE has good oxygen reduction ability, and also enhances methanol reduction. Diffusion coefficient values were calculated for PoT/GCE in different atmospheric condition using Chronoamperometric and Chronocoulometric studies. The double layer capacitance value of the resistance is 1.5948 × 10−10F/cm2 which was determined by electrochemical impedance spectroscopy (EIS).

Wide-ranging application in various fields from biomedicine, catalysis and optoelectronic materials to sensors, and environmental pollution prevention by synthesising Metal oxide nanoparticles. In this present work Eco-friendly synthesis of Nickel Oxide Nanoparticles (NiO-NPs) using Avicennia Marina leaf extract in an aqueous medium. The prepared NiO-NPs were characterized by UV–Visible, FT-IR, X-ray diffraction, AFM, FE-SEM, TEM, and electrochemical techniques to find the band gap energy, functional group, grain size, morphology, and the structure, particle size respectively. UV–Vis absorption spectrum of nickel oxide nanoparticles (NiO-NPs) shows a peak in the region of 297 nm. The FTIR spectrum of NiO-NPs shows bands at 872 cm−1 and 466 cm−1. From the FESEM results, the average size of NiO-NPs is seen to be in the range of 30–100 nm. Electrochemical studies were carried out to assess the redox behavior of NiO-NPs. The obtained results confirmed the formation of nickel oxide nanoparticles from the biomaterial leaf component. The methanol oxidation of NiO-NPs has been studied by voltammetry.

Green synthesis of nanoparticles is gaining importance and has been suggested as possible alternatives to chemical and physical methods. The present work reports low- cost, green synthesis of zinc oxide (ZnO) & Ag doped ZnO nanoparticles using Vitis vinifera leaf extract. The biosynthesized nanoparticles were characterized by SEM, EDX, UV–vis, and FTIR. In the present work, the biosynthesized ZnO nanoparticle & Ag doped ZnO nanoparticles have been used for antibacterial and photocatalytic applications. The antibacterial activity of characterized samples was determined against Gram-positive and Gram-negative bacteria. The obtained results revealed that the bacterial growth decreases with increase in the concentration of biosynthesized ZnO nanoparticles. Also, Gram-positive bacteria seemed to be more sensitive to ZnO & Ag doped ZnO nanoparticles than Gram-negative bacteria. The biosynthesized ZnO nanoparticles showed photocatalytic activity under the UV light enhancing the degradation rate of methylene blue (MB), which is one of the main water- pollutants released by textile industries.

We have explored the nanocomposites as a potential catalyst material in acid medium for the electro-oxidation of methanol. Electrochemical impedance studies have shown that the Rct value of (Poly-3-Anisidine) P3A/GCE is lower than the modified P3A-metal oxide doped electrodes. In the case of doped metal oxides, we claim, this validates the slow electron transfer mechanism. Compared to P3A-MnO2, P3A-Fe2O3 catalysts, the as-synthesized P3A-Cr2O3 displays an expanded electrochemically active surface region, substantially enhanced catalytic activity and improved stability for methanol oxidation reaction (MOR).

Polymers have exhibited a promising ability for the corrosion protection of metals. In the present study, poly(o-anisidine) (POA) nanoparticles and its nanocomposites with silicon dioxide (SiO2) like POA/SiO2 containing different compositions content of SiO2 (5%, 10% & 15% w/w) were prepared by chemical oxidative polymerization. FT-IR spectra of POA/SiO2 composites indicate the presence of SiO2 nanoparticles in the polymer nanocomposites. The X-ray diffraction (XRD) studies was showed more crystalline behavior of polymer nanocomposites and the particle grain size was calculated using Scherer’s formula and it was found to be within nano range. The surface morphology of the polymer composites were investigated by Scanning Electron Microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) confirms the incorporation of silicon and oxygen in the polymer nanocomposites. Further the synthesized polymeric composites were introduced into acrylic resin and the polymer/SiO2/acrylic hybrid materials were applied on the surface of mild steel sample. The corrosion efficiency and corrosion rate of the polymer nanocomposites were calculated for mild steel in 3.5% NaCl solution using Polarization curve and Electrochemical Impedance Spectroscopy (EIS).

Nano structured metal oxides received considerable research attention due to their unique properties that can be used for designing advanced nanodevices. Thus, in the present study, Tungsten oxide/graphene oxide (WO3/GO) nanocomposite was synthesized, characterized and implemented in an electrochemical system. Graphene oxide was synthesized by Hummer’s method. WO3 doped Graphene oxide nanocomposite were also successfully synthesized using sodium tungstate as the source of Tungsten. The crystalline structure and optical properties of WO3 doped GO nanocomposite were characterized by UV–VIS spectroscopy, IR spectroscopy, X-ray diffraction (XRD) studies, Field Emission Scanning Electron Microscope (FESEM) with EDAX spectroscopy. The XRD spectrum showed diffraction peaks corresponding to the crystal planes of crystalline Tungsten oxide. Using Debye scherrer formula, the size of the undoped and Tungsten oxide doped Graphene oxide nanocomposite were also calculated. The morphological studies of the nanocomposite revealed crystal like morphology. The energy dispersive analysis confirmed the presence of Carbon, Tungsten and oxygen in the doped WO3/GO lattice. Cyclic voltammetric behaviour showed better electrochemical response with the doped sample when compared with the undoped sample.

Nano composites of conducting polyaniline with ZnS nanoparticles (PANI/ZnS) have been synthesized by in-situ polymerization of aniline monomer using ammonium persulphate as oxidizing agent. The formation of PANI/ZnS composites was assessed by UV–Vis spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscope (FTIR), Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM) and X ray diffraction analysis (XRD). FTIR and UV studies provided the information of functional group and optical behavior respectively SEM studies shows the well dispersion of ZnS Nanoparticles in the polyaniline matrix. Size determination identified and confirmed by TEM analysis.

Polyanilines doped with different concentrations of oxalic acid have been synthesized by oxidative chemical polymerization using potassium perdisulfate as oxidizing agent. The effect of dopant on the kinetics of polymerization has been studied by UV–VIS spectroscopy. The presence of oxalic acid in the polymer has been studied by FTIR, and morphology by SEM and TEM. The thermal stability of the polymer was investigated by TGA and degree of crystallinity of polyaniline was studied by XRD. The electrochemical behaviour has been studied by cyclic voltammetry (CV) and the phenomenon of charge transport and capacitance was examined by Electrochemical Impedance Spectroscopy (EIS). The morphological study shows the particles to be of nanosize and EIS studies show that these samples have significant double layer capacitance (Cdl) and can be used as capacitors.

Zinc oxide nanoparticles were synthesized through wet chemical method. Polyaniline was synthesized by oxidative polymerization of aniline using potassium perdisulphate as oxidizing agent. Polyaniline -Zinc oxide nanocomposites were prepared by five different percentages of zinc oxide nanoparticles mixed with synthesized polyaniline. The prepared metal oxide, polymer and Nano composites were characterized by UV–Vis, FT-IR, AFM and electrochemical studies. The FT-IR spectral studies indicated the presence of metal oxide and polymer in Nano composites. From the FT-IR spectra of Nano composites, the peak around 464 cm−1 indicated the bonding between Zn and O, the peak around 1573 cm−1 and 1503 cm−1 due to stretching vibrations of the quinonoid and benzenoid rings of polyaniline respectively. The surface morphology was characterized by AFM. The UV–Vis spectrum of polyaniline was observed five absorption bands around 230 nm, 258 nm, 299 nm, 457 nm and 632 nm. Among these five bands, the absorption band around 299 nm is assigned to the π–π* transition of the phenyl ring and another band at 632 nm is assigned to the polaron n–π* transition. The UV–vis spectral absorption intensity of Nano composites was increased as increasing of zinc oxide incorporation in polyaniline. Cyclic Voltammetric studies exhibit good sensitivity response at pH 1.0. Chronoamperometric and Chronocoulometric studies were also carried out for polymer–metal oxide nanocomposites. The present study especially aims to investigate PAni-ZnO Nano composites in order to obtain a new noble material which can be utilized for solar cell applications.

Nanocomposite of Zinc doped Iron oxide/Graphene Oxide/Chitosan was prepared using optimized quantity of the components by simple solution mixing-evaporation method. The structure of the composite was studied by UV–Vis, FTIR, XRD, SEM, HRTEM and AFM. The results obtained from these analyses showed the formation of homogeneous mixture with strong interaction between the constituents and evidenced by the shift in peak position in both UV–Vis and FTIR spectra. Band gap calculated was found to be 2.28eV which indicates the conducting nature of the composite. The formation of composite in nano dimensions of around 20 nm was proved by XRD, SEM and HRTEM studies. Thermal stability of the sample was investigated by TG/DTA and DSC techniques and showed improved thermal stability with the increase in glass transition temperature of chitosan by 78°c. Electrochemical characteristics of the composite was studied by cyclic voltammetry and capacitative behavior was studied by impedance studies (EIS). These electrochemical investigations revealed good adherent nature of the composite on electrode surface at pH1 and greater electrochemical stability with well defined redox peaks. EIS showed that the nanocomposite modified electrode exhibited good capacitance behavior with the bode phase angle of 87° which proves it to be a very good candidate for supercapacitor applications.

Toluidine was polymerized with montmorillonite (Mt) by the chemical oxidation method using potassium perdisulfate by varying the toluidine to clay ratio. The solubility of the chemically prepared clay-polymer nanocomposites (CPN) was ascertained and it showed good solubility in DMSO and DMF. The in situ intercalative polymerization of o-toluidine (POT) within the Mt layers was analyzed by FTIR, UV–visible, XRD, SEM and TEM. The analyses of UV visible and FTIR spectroscopy demonstrated that o-toluidine has been polymerized to POT in its conducting emeraldine form. The conformation adopted by POT chains in the Mt interlayer depended on the molar ratio of o-toluidine to montmorillonite. FTIR spectra showed that amine vibration peak observed at 1593 cm− 1 was shifted to lower wave numbers when the CPN were formed. SEM analysis showed the variation in morphology from granular agglomerate to layered flaky structure as the clay mineral concentration was increased. Elemental analysis was done by EDAX which shows the presence of Na, Mg Al, Si, C and N. Thermal stability of the CPN was studied using TGA/DTA and DSC studies. The X-ray diffraction studies revealed the formation of nano sized (28 nm) crystalline CPN. Cyclic voltammetric studies of the synthesized CPN exhibited good adherent behavior on electrode surface at pH 1.0. It exhibited one oxidation peak at 0.405 V and one reduction peak at 0.299 V. By varying the atmosphere it was found that the CPN modified electrode exhibited oxygen reducing capacity.

3,4-Ethylenedioxy thiophene is polymerized electrochemically in p-toluene sulphonic acid (a), phosphate buffer (b) and borax buffer (c) on glassy carbon and Indium tin oxide (ITO) surface. The scan rate dependence studies of the polymer redox processes were carried out. A linear relationship was observed between the peak current and scan rate with good correlation, r2 = 0.998 indicating adsorption controlled behaviour of polymer film. The SEM photograph showed the differences in surface morphology of polymers modified electrode. The XRD studies revealed semi-crystalline nature of doped polymers. Spectroelectrochemical behaviors of Indium tin oxide coated glass electrode covered with thin film of poly-3,4-ethylenedioxythiophene a, b, c in 0.1 M KCl were obtained at different electrode potentials between 1100 and 200 nm. Poly-3,4-ethylenedioxythiophene-a, poly-3,4-ethylenedioxythiophene-b and poly-3,4-ethylenedioxythiophene-c film exhibits transparent clear blue, opaque violet and dark maroon colours respectively at reduced potential. Further probing the potential between 400 mV and 800 mV coated film shows greenish blue colour for poly-3,4-ethylenedioxythiophene-a, poly-3,4-ethylenedioxythiophene-b and poly-3,4-ethylenedioxythiophene -c shows opaque violet and yellowish maroon colours respectively. Increasing the applied potential between 1000 mV and 1200 mV over oxidation of polymer film shows dark greenish blue for poly-3,4-ethylenedioxythiophene -a, dark brown for poly-3,4-ethylenedioxythiophene-b and transparent red colour for poly-3,4-ethylenedioxythiophene-c. Electrochromic parameters such as colouration efficiency, response time and optical contrast were calculated for all three films.

Nearly perfect single crystal of L-tyrosine hydrobromide (LTHB) has been grown at room temperature from the saturated solution prepared from the solvent with optimised normality (2N) using slow evaporation solution growth technique. Crystal system and lattice parameters have been estimated by single crystal X-ray diffraction analysis. Prominent peeks of powder X-ray diffraction pattern have been indexed and diffraction data have been presented. The presence of various functional groups in LTHB has been identified by vibrational and Nuclear Magnetic Resonance spectral study. The crystalline nature and defect during the growth has been studied by obtaining high resolution X-ray diffraction curve (rocking curve) for the title crystal and detailed explanation is given in this paper. Cyclic voltammetric behaviour and photoluminescence properties of LTHB have also been investigated.

Nearly perfect single crystals of l -histidine hydrochloride monohydrate have been grown from the solution prepared from the mixture of l -histidine and hydrochloric acid using slow evaporation solution growth technique. Single crystal X-ray diffraction analysis, High resolution X-ray diffraction analysis, fourier transform infrared and FT-Raman analyzes were employed for structural characterization. Linear and nonlinear optical properties have been studied by UV–Vis transmission spectrum and Kurtz Perry technique respectively. The refractive index, redox behavior and hardness of the grown crystal have been found by suitable methods. Thermogravimetric, differential thermal analysis were employed to characterize the as-grown crystals. The second harmonic generation conversion efficiency of the grown crystal and other properties show the suitability of the grown crystal for frequency conversion applications.

4, 4′-Diaminodiphenyl sulphone was polymerized (with lithium/cobalt/lithium–cobalt salts) by chemical oxidation method using potassium perdisulphate. The solubility of the chemically prepared polymer–metal nanocomposite was ascertained and it showed good solubility in DMF, chloroform, trichloroethylene and DMSO. The PDDS–Li/Co/Li–Co nanocomposites were characterized by UV–vis and FTIR spectral studies. Amine and imine vibrations observed at 1593 and 1503 cm −1 were shifted to lower wave numbers when the polymer–metal composites were formed. A single absorption peak due to the N–H stretching vibration of the imino groups of polymer–metal nanocomposite is observed around 3459 cm −1 and it suggests the participation of NH group during polymerization. The X-ray diffraction studies revealed the formation of nano sized (82 nm) crystalline polymer. The conductivity of the PDDS–Li–Co nanocomposite was determined to be 6.26 × 10 −2 S cm −1 . SEM analysis showed mixed granular nature of the polymer–metal nanocomposite. The capacitance (159.04 μF) of chemically synthesized PDDS–Li–Co nanocomposite is suggested as a potential capacitive material.

Three analgesics were studied voltammetrically using a sodium montmorillonite (NaMM) modified glassy carbon electrode. The voltammograms of analgesics were studied in pHs 1.0–13.0. Influence of pH, sweep rate and pharmaceutical formulations concentration were studied. One well-defined oxidation peak was observed for acetaminophen (AAP) and acetylsalicylic acid (ASA), three oxidation peaks for dipyrone (DP). The oxidation peak potential shifted towards negatively with change in pH. The oxidation was irreversible and diffusion-controlled for all pharmaceutical samples of acetaminophen, dipyrone, and acetylsalicylic acid. A systematic study of the experimental parameters that affect the square wave stripping voltammetric response was carried out and optimized conditions were arrived at. Under optimum conditions, stripping voltammetric procedure was developed for the determination of analgesics in pharmaceutical and urine at pH 1.0. A calibration plot was derived and the lower limit of determination was noticed as 0.02 μg mL − 1 for acetylsalicylic acid, 0.02 μg mL − 1 for acetaminophen and 0.04 μg mL − 1 for dipyrone. The percentage of rsd was also found.

Aniline was copolymerized chemically in presence of five different concentrations of 4,4′-diaminodiphenyl sulphone using potassium persulphate. The copolymer exhibited good solubility in DMF and DMSO. Copolymers were characterized by UV–VIS, FTIR, XRD and SEM studies. The formation of polymer through N–H group was understood from the single N–H stretching vibrational frequency at 3378 cm −1 and bands at 1630 and 1494 cm −1 for quinonoid and benzenoid structures, respectively. The stretching vibration of sulphone S O at 1115 cm −1 clearly indicated the presence of DDS in the copolymer. The X-ray diffraction studies revealed the formation of nano sized crystalline copolymer. When more DDS was incorporated in the copolymer the crystalline nature changed from less to more. The grain size of the copolymer calculated from Scherrer's formula was 83 nm. The nano size copolymer formation was also confirmed through surface morphology (100 nm) studies. The electrical property of the copolymer was studied by four-probe conductivity meter. The synthesized polymers have conductivity of 7.21 × 10 −3 to 2.07 × 10 −3 S cm −1 . The voltammetric and spectroelectrochemical results were also presented.

Copolymers prepared from 3,4-ethylenedioxythiophene (EDOT) and Diclofenac (DCF) through cyclic voltammetric method exhibited electroactive and electrochromic behaviours. Addition of DCF produced bathochromic shift of the EDOT main absorption band from 253.4 to 269.7 nm in the UV–vis spectra. The cyclic voltammetric studies were carried out with different feed concentration of DCF and in the presence of two different surfactants, SDS and CTAB on glassy carbon electrode surface. Effect of scan rate on the three types of electroactive copolymer films was studied. The three different copolymers showed good adherence on the glassy carbon electrode surface in aqueous 0.1 M KCl medium. Spectroelectrochemical analysis of copolymer film was carried out on Indium–Tin-Oxide (ITO) plate and it showed multicolor electrochromic behaviour when the applied potential was changed. The color of the copolymer was changed from neutral yellow to brown and to violet in 0.1 M KCl medium. Among the three different copolymers, the copolymer prepared in presence of CTAB resulted in high contrast colors. The electrochromic parameters such as coloration efficiency, optical contrast, response time and stability were also evaluated. The surface morphology of the copolymer films was characterized by SEM analysis.

Redox behavior of two pesticides namely isoproturon and carbendazim were investigated electrochemically using sodium montmorillonite clay-modified glassy carbon electrode in the presence and absence of a surfactant, cetyl trimethyl ammonium bromide. A solution of 0.1 M H 2 SO 4 in both 50% aqueous alcohol (pH 1.0) was found to be a suitable medium for electroanalysis. Isoproturon exhibited one well-defined oxidation peak around 1.17 V along with one more oxidation and reduction peaks. Carbendazim showed only one well-defined anodic peak around 1.5 V. The main electron transfer was irreversible and the mass transfer was by diffusion for both cases. Controlled potential coulometric studies revealed 2e − and 1e − transfer for isoproturon and carbendazim, respectively. The surfactant had only little effect on the electrochemical properties of isoproturon and pronounced effect with carbendazim. Electroanalytical procedure for the determination of these pesticides was developed using differential pulse stripping voltammogram under their maximum current experimental conditions. Calibration plot was made for both pesticides. The determination limit and standard deviations were arrived at. The applicability of the method was also verified in a soil sample and water analyte.