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Clay minerals can act as a uniform dispersion medium for nano-sized carbon particles. However, literature on the preparation and characteristics of palygorskite-carbon nanocomposites is scant. Using a hydrothermal carbonisation technique this study developed two nanocomposites on fibrous palygorskite from starch: the first without a post-synthesis treatment (Composite 1); and the second with an activation at 550°C for 3h (ramp at 10°Cmin-1) under CO2 environment (200mLmin-1) (Composite 2). A uniform dispersion of nano-scale carbon spheres was formed on partially destroyed palygorskite structures. Composite 2, which indicated the formation of graphitised carbon nanoparticles, generated a 17-fold greater specific surface area than Composite 1 and also created micro- and mesopores in its structure. The nanocomposites, especially in Composite 1, contained organic surface functional groups (CH, CC, CO) and indicated variable affinity to cationic and anionic dye compounds. While Composite 2 adsorbed a larger amount of anionic orange II dye (23mgg-1), Composite 1 adsorbed more cationic methylene blue (46.3mgg-1). Isothermal and kinetic modelling of the adsorption data indicated that in addition to electrostatic attraction for methylene blue adsorption on both nanocomposites, a pore diffusion mechanism was involved and the boundary resistance was greater for orange II than methylene blue adsorption. Being a material developed from green biomass (starch) and an abundant natural resource (palygorskite), these nanocomposites have immense potential for application in environmental remediation including in situ immobilisation of contaminants in soil. Refereed/Peer-reviewed

In this work, we demonstrate a facile method for fabricating hybrid organic/inorganic structures of vertically oriented 1-dimensional (1-D) ZnO nanorods (NR) coupled with regio-regular poly(3-(2-methoxyethoxy) ethoxymethyl) thiophene-2,5-diyl (PMEEMT). The NRs were synthesized by two-step solution processes and exhibited a hexagonal wurtzite structure with a lattice spacing of 0.248 nm. Cross-section analysis of field-emission scanning electron microscopy (FESEM) analysis confirmed the NRs were vertically oriented and densely packed with diameter of about 250 nm. The hybrid structures were formed by encapsulating the ZnO NRs with polythiophenes, thereby creating a direct heterojunction interface. These interfaces allowed easy electron transport along the NR avoiding loss of mobility due to grain boundary scattering; further, the large aspect ratio and surface area of NR increased the effective interface between polythiophene and the nanorods contributing to efficient charge separation. In addition, decoration of the ZnO hybrid structures by gold nanoparticles (AuNPs) induced enhanced luminescence properties. These functionalized organic/inorganic hybrid structures can pave the way for applications in photovoltaics and sensing. Refereed/Peer-reviewed

This is the first report of the utilization of TiNb2 O7 as an insertion-type anode in a lithium-ion hybrid electrochemical capacitor (Li-HEC) along with an activated carbon (AC) counter electrode derived from a coconut shell. A simple and scalable electrospinning technique is adopted to prepare one-dimensional TiNb2 O7 nanofibers that can be characterized by XRD with Rietveld refinement, SEM, and TEM. The lithium insertion properties of such electrospun TiNb2 O7 are evaluated in the half-cell configuration (Li/TiNb2 O7 ) and it is found that the reversible intercalation of lithium (≈3.45 mol) is feasible with good capacity retention characteristics. The Li-HEC is constructed with an optimized mass loading based on the electrochemical performance of both the TiNb2 O7 anode and AC counter electrode in nonaqueous media. The Li-HEC delivers very high energy and power densities of approximately 43 Wh kg(-1) and 3 kW kg(-1) , respectively. Furthermore, the AC/TiNb2 O7 Li-HEC delivers a good cyclability of 3000 cycles with about 84% of the initial value.

Polymer templates realized through a combination of block copolymer lithography (BCL) and nanoimprint lithography (NIL) are used to direct atomic layer deposition (ALD) to obtain high-quality ZnO nanopatterns. These patterns present a uniform array of ZnO nanostructures with sub-100 nm feature and spatial resolutions, exhibiting narrow distributions in size and separation, and enhanced mechanical stability. The process benefits from the high lateral resolutions determined by the copolymer pattern, controlled growth rates, material quality and enhanced mechanical stability from ALD and repeatability and throughput from NIL. The protocol is generic and readily extendible to a range of other materials that can be grown through ALD. By virtue of their high feature density and material quality, the electrical characteristics of the arrays incorporated within MOS capacitors display high hole-storage density of 7.39 × 1018 cm–3, excellent retention of 97% (for 1000 s of discharging), despite low tunneling oxide thickness of 3 nm. These attributes favor potential application of these ZnO arrays as charge-storage centers in nonvolatile flash memory devices.

Controlled assembly of nanoparticles on substrates is a promising path to develop miniaturized electronic and optical devices. Among the important issues to be addressed in this area include immobilization of the nanoparticles on substrates in order to ensure that the system is robust. In this work, 16-mercaptohexadecanoic acid (16-MHDA) capped gold nanoparticles with a narrow size distribution have been synthesized through a single phase synthesis method and subsequently immobilized on to silicon surface through covalent molecular assembly. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the absence of unreacted thiol in the synthesized gold nanoparticles. Presence of gold nanoparticles on Si surface after the immobilization process was confirmed through XPS. Cross-sectional high resolution transmission electron microscopy (HR-TEM) images provide direct evidence that the particles are indeed anchored to the silicon surface. The formation of uniform-sized and separated acid functionalized gold nanoparticles and their immobilization on to Si provide a basis for further nano-structuring. Refereed/Peer-reviewed

Organic dyes are one of the largest groups of pollutants released into wastewaters from textile and other industrial processes. Because of potential toxicity of the dyes and their visibility in surface waters, removal and degradation of organic dyes have been a matter of considerable interest. A wide range of methods have been developed, amongst which the heterogeneous photocatalysis involving titanium dioxide (TiO2) appears to be the most promising technology. This paper presents a critical review of novel achievements in the modification of TiO2 photocatalytic systems aimed at: enhanced TiO2 photocatalytic efficiency; complete mineralization of organic dyes; efficient utilization of visible and/or solar light; stability and reproducibility of the modified TiO2; recycle and reuse in real wastewater treatment. Refereed/Peer-reviewed

The fabrication details of a precision electronic gas flow controller designed to suit the requirements of available vacuum coating systems are presented. Its performance is compared with that of a commercially available gas flow controller. The incorporation of a precision reference source with coarse and fine controls in the present controller has not only improved its resolution and stability compared with the commercial controller, but also enabled exact setting of flow rates even for the minimum flow rates. The coarse and fine controls have another major advantage in transferring the flow control system from one vacuum system to the other as it could be set with respect to any chamber volume to pump speed ratio. The performance of the controller has been studied with a reactive evaporation system in the range $7^*10^{-2} to 1^*10^{-3}$ Pa and with a reactive sputtering system in the range 13 to $10^{-1}$ Pa and the results are presented.