The silver nanoparticle (AgNP) coated graphene oxide (GO) hybrid nanofiller (Ag@GO) reinforced polyaniline (PANI) nanocomposite via in situ polymerisation method is synthesised. Fourier transform infrared (FTIR) spectroscopy analysis revealed the existence of chemical interactions between the Ag@GO hybrid nanofiller and the PANI matrix. The ultraviolet-visible (UV-VIS) spectroscopy showed the presence of a silver nanoparticle peak. The nanostructure morphology of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) established the presence of AgNPs on the surface of the GO nanosheets that successfully reinforced into the PANI matrix. The thermogravimetricdifferential scanning calorimetry (TG-DSC) thermograms revealed that the thermal stability of the PANI/Ag@GO nanocomposite was significantly enhanced due to the synergistic effect imparted by the AgNPs, GO, and PANI matrix. The dielectric relaxation spectroscopy (DRS) study indicated that the dielectric behaviour of the PANI/Ag@GO nanocomposite was enhanced because of the strong interfacial interactions existing between the Ag@GO hybrid nanofiller and PANI matrix.Polyaniline/Ag@GO nanocomposite has been prepared via in situ polymerisation method. The results showed that the thermal stability as well as the dielectric properties of the PANI/ Ag@GO nanocomposite increases due to the synergistic effect imparted by the GO, AgNP, and PANI, which may be suitable for application in the energy storage devices.

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Our recent studies on metal-organic nanohybrids based on alkylated graphene oxide (GO), reduced alkylated graphene oxide (RGO) and InP/ZnS core/shell quantum dots (QDs) are presented. The GO alkylated by octadecylamine (ODA) and the QD bearing a dodecane thiol (DDT) ligand are soluble in toluene. The nanocomposite alkylated-GO-QD (GOQD) is readily formed from the solution mixture. Treatment of the GOQD composite with hydrazine affords a reduced-alkylated-GO-QD (RGOQD) composite. The structure, morphology, photophysical and electrical properties of GOQDs and RGOQDs are studied. The micro-FTIR and Raman studies demonstrate evidence of the QD interaction with GO and RGO through facile intercalation of the alkyl chains. The field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) images of the GOQD composite show heaps of large QD aggregates piled underneath the GO sheet. Upon reduction to RGOQDs, the QDs become evenly distributed on the graphene bed and the size of the clusters significantly decreases. This also facilitates closer proximity of the QDs to the graphene domains by altering the optoelectronic properties of the RGOQDs. The X-ray photoelectron spectroscopy (XPS) results confirm QDs being retained in the composites, though a small elemental composition change takes place. The XPS and the fluorescence spectra show the presence of an In(Zn)P alloy while the X-ray diffraction (XRD) results show characteristics of the tetragonal indium. The photoluminescence (PL) quenching of QDs in GOQD and RGOQD films determined by the time correlated single photon counting (TCSPC) experiment demonstrates almost complete fluorescence quenching in RGOQDs. The conductance studies demonstrate the differences between GOQDs and RGOQDs. Investigation on the metal-oxide-semiconductor field-effect transistor (nMOSFET) characteristics shows the composite to exhibit p-type channel material properties. The RGOQD exhibits much superior electrical conductance as a channel material compared to the GOQD due to the close proximity of the QDs in the RGOQD to the graphene surface. The transfer characteristics, memory properties, and on/off ratios of the devices are determined. A mechanism has been proposed with reference to the Fermi energies of the composites estimated from the ultraviolet photoelectron spectroscopy (UPS) studies.

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