Synergetic Strategy for the Fabrication of Self-Standing Distorted Carbon Nanofibers with Heteroatom Doping for Sodium-Ion Batteries.

Currently, the limited availability of lithium sources is escalating the cost of lithium-ion batteries (LIBs). Considering the fluctuating economics of LIBs, sodium-ion batteries (SIBs) have now drawn attention because sodium is an earth-abundant, low-cost element that exhibits similar chemistry to that of LIBs. Despite developments in different anode materials, there still remain several challenges in SIBs, including lighter cell design for SIBs. The presented work designs a facile strategy to prepare nitrogen-doped free-standing pseudo-graphitic nanofibers via electrospinning. A structural and morphological study implies highly disordered graphitic structured nanofibers having diameters of ∼120-170 nm, with a smooth surface. X-ray photoelectron spectroscopy analysis showed that nitrogen was successfully doped in carbon nanofibers (CNFs). When served as an anode material for SIBs, the resultant material exhibits excellent sodium-ion storage properties in terms of long-term cycling stability and high rate capability. Notably, a binder-free self-standing CNF without a current collector was used as an anode for SIBs that delivered capacities of 210 and 87 mA h g-1 at 20 and 1600 mA g-1, respectively, retaining a capacity of 177 mA h g-1 when retained at 20 mA g-1. The as-synthesized CNFs demonstrate a long cycle life with a relatively high Columbic efficiency of 98.6% for the 900th cycle, with a stable and excellent rate capacity. The sodium storage mechanisms of the CNFs were examined with various nitrogen concentrations and carbonization temperatures. Furthermore, the diffusion coefficients of the sodium ions based on the electrochemical impedance spectra measurement have been calculated in the range of 10-15-10-12 cm2 s-1, revealing excellent diffusion mobility for Na atoms in the CNFs. This study demonstrates that optimum nitrogen doping and carbonization temperature demonstrated a lower Warburg coefficient and a higher Na-ion diffusion coefficient leads to enhanced stable electrochemical performance. Thus, our study shows that the nitrogen-doped CNFs will have potential for SIBs.

Efficient solar light-driven hydrogen generation using an Sn3O4 nanoflake/graphene nanoheterostructure.

Herein, we report Sn3O4 and Sn3O4 nanoflake/graphene for photocatalytic hydrogen generation from H2O and H2S under natural "sunlight" irradiation. The Sn3O4/graphene composites were prepared by a simple hydrothermal method at relatively low temperatures (150 °C). The incorporation of graphene in Sn3O4 exhibits remarkable improvement in solar light absorption, with improved photoinduced charge separation due to formation of the heterostructure. The highest photocatalytic hydrogen production rate for the Sn3O4/graphene nanoheterostructure was observed as 4687 µmol h-1 g-1 from H2O and 7887 µmol h-1 g-1 from H2S under natural sunlight. The observed hydrogen evolution is much higher than that for pure Sn3O4 (5.7 times that from H2O, and 2.2 times from H2S). The improved photocatalytic activity is due to the presence of graphene, which acts as an electron collector and transporter in the heterostructure. More significantly, the Sn3O4 nanoflakes are uniformly and parallel grown on the graphene surface, which accelerates the fast transport of electrons due to the short diffusion distance. Such a unique morphology for the Sn3O4 along with the graphene provides more adsorption sites, which are effective for photocatalytic reactions under solar light. This work suggests an effective strategy towards designing the surfaces of various oxides with graphene nanoheterostructures for high performance of energy-conversion devices.

A nanostructured SnO2/Ni/CNT composite as an anode for Li ion batteries.

A SnO2/Ni/CNT nanocomposite was synthesized using a simple one-step hydrothermal method followed by calcination. A structural study via XRD shows that the tetragonal rutile structure of SnO2 is maintained. Further, X-ray photoelectron spectroscopy (XPS) and Raman studies confirm the existence of SnO2 along with CNTs and Ni nanoparticles. The electrochemical performance was investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The nanocomposite has been used as an anode material for lithium-ion batteries. The SnO2/Ni/CNT nanocomposite exhibited an initial discharge capacity of 5312 mA h g-1 and a corresponding charge capacity of 2267 mA h g-1 during the first cycle at 50 mA g-1. Pristine SnO2 showed a discharge/charge capacity of 1445/636 mA h g-1 during the first cycle at 50 mA g-1. This clearly shows the effects of the optimum concentrations of CNTs and Ni. Further, the nanocomposite (SnNiCn) shows a discharge capacity as high as 919 mA h g-1 after 210 cycles at a current density of 400 mA g-1 in a Li-ion battery set-up. Thus, the obtained capacity from the nanocomposite is much higher compared to pristine SnO2. The higher capacity in the nanoheterostructure is due to the well-dispersed nanosized Ni-decorated stabilized SnO2 along with the CNTs, avoiding pulverization as a result of the volumetric change of the nanoparticles being minimized. The material accommodates huge volume expansion and avoids the agglomeration of nanoparticles during the lithiation and delithiation processes. The Ni nanoparticles can successfully inhibit Sn coarsening during cycling, resulting in the enhancement of stability during reversible conversion reactions. They ultimately enhance the capacity, giving stability to the nanocomposite and improving performance. Additionally, the material exhibits a lower Warburg coefficient and higher Li ion diffusion coefficient, which in turn accelerate the interfacial charge transfer process; this is also responsible for the enhanced stable electrochemical performance. A detailed mechanism is expressed and elaborated on to provide a better understanding of the enhanced electrochemical performance.

Synergic effects of the decoration of nickel oxide nanoparticles on silicon for enhanced electrochemical performance in LIBs.

Significant efforts continue to be directed toward the construction of anode materials with high specific capacity and long cycling stability for lithium-ion batteries (LIBs). In this context, silicon is preferred due to its high capacity even though it has a problem of excessive volume expansion during electrochemical reactions as well as poor cyclability due to a reduction in conductivity. Hence, the hybridization of silicon with suitable materials could be a promising approach to overcome the abovementioned problems. Herein, we demonstrate the uniform decoration of nickel oxide (NiO) nanoparticles (15-20 nm) on silicon nanosheets using bis(cyclopentadienyl) nickel(ii) (C10H10Ni) at low temperatures, taking advantage of the presence of two unpaired electrons in an antibonding orbital in the cyclopentadienyl group. The formation and growth mechanism are discussed in detail. The electrochemical study of the nanocomposite revealed an initial delithiation capacity of 2507 mA h g-1 with a reversible capacity of 2162 mA h g-1, having 86% retention and better cycling stability for up to 500 cycles. At the optimum concentration, NiO nanoparticles facilitate Li+-ion adsorption, which in turn accelerates the transport of Li+-ions to active sites of silicon. The Warburg coefficient and Li+-ion diffusion at the electrodes confirm the enhancement in the charge transfer process at the electrode/electrolyte interface with NiO nanoparticles. Further, the NiO nanoparticles with uniform distribution suppress the agglomeration of Si nanosheets and provide sufficient space to accommodate a volume change in Si during cycling, which also reduces the diffusion path length of the Li-ions. It also helps to strengthen the mechanical stability, which might be helpful in preventing the cracking of silicon due to volume expansion and maintains the Li-ion transport pathway of the active material, resulting in enhanced cycling stability. Due to the synergic effect between NiO nanoparticles and Si sheets, the nanocomposite delivers high reversible capacity.

Plasmonic Ag decorated CdMoO4 as an efficient photocatalyst for solar hydrogen production.

The synthesis of Ag-nanoparticle-decorated CdMoO4 and its photocatalytic activity towards hydrogen generation under sunlight has been demonstrated. The CdMoO4 samples were synthesized by a simple hydrothermal approach in which Ag nanoparticles were in situ decorated on the surface of CdMoO4. A morphological study showed that 5 nm spherical Ag nanoparticles were homogeneously distributed on the surface of CdMoO4 particles. The UV/DRS spectra show that the band gap of CdMoO4 was narrowed by the incorporation of a small amount of Ag nanoparticles. The surface plasmonic effect of Ag shows broad absorption in the visible region. The enhanced photocatalytic hydrogen production activities of all the samples were evaluated by using methanol as a sacrificial reagent in water under natural sunlight conditions. The results suggest that the rate of photocatalytic hydrogen production using CdMoO4 can be significantly improved by loading 2% Ag nanoparticles: i.e. 2465 µmol h-1 g-1 for a 15 mg catalyst. The strong excitation of surface plasmon resonance (SPR) absorption by the Ag nanoparticles was found in the Ag-loaded samples. In this system, the role of Ag nanoparticles on the surface of CdMoO4 has been discussed. In particular, the SPR effect is responsible for higher hydrogen evolution under natural sunlight because of broad absorption in the visible region. The current study could provide new insights for designing metal/semiconductor interface systems to harvest solar light for solar fuel generation.

Correction: Unique perforated graphene derived from Bougainvillea flowers for high-power supercapacitors: a green approach.

Correction for 'Unique perforated graphene derived from Bougainvillea flowers for high-power supercapacitors: a green approach' by Rajendra P. Panmand et al., Nanoscale, 2017, 9, 4801-4809.

Surface modified Li4Ti5O12 by paper templated approach for enhanced interfacial Li+ charge transfer in Li-ion batteries.

The Li4Ti5O12 (LTO) and lithium silicate (LS) surface modified LTO have been demonstrated by a unique paper templated method. Comparative study of structural characterization with electrochemical analysis was demonstrated for pristine and modified Li4Ti5O12. Structural and morphological study shows the existence of the cubic spinel structure with highly crystalline 250-300 nm size particles. The LS modified LTO shows the deposition of 10-20 nm sized LS nanoparticles on cuboidal LTO. Further, X-ray photoelectron spectroscopy (XPS) confirms the existence of Li2SiO3 (LS) in the modified LTO. The electrochemical performance was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge. The modified LTO with 2% LS (LTS2) exhibited excellent rate capability compare to pristine LTO i.e. 182 mA h g-1 specific capacity at a current rate, 50 mA g-1 with remarkable cycling stability up to 1100 cycles at a current rate of 800 mA g-1. The lithium ion full cell of modified LTO with LS as an anode and LiCoO2 as a cathode exhibited a remarkably reversible specific capacity i.e. 110 mA h g-1. Both electronic and ionic conductivities of pristine LTO are observed to be enhanced by incorporation of appropriate amount of LS in LTO due to a larger surface contact at the interface of electrode and electrolyte. More significantly, the versatile paper templated synthesis approach of modified LTO with LS provides densely packed highly crystalline particles. Additionally, it exhibits lower Warburg coefficient and higher Li ion diffusion coefficient which in turn accelerate the interfacial charge transfer process, which is responsible for enhanced stable electrochemical performance. The detailed mechanism is expressed and elaborated for better understanding of enhanced electrochemical performance due to the surface modification.

Growth study of hierarchical Ag3PO4/LaCO3OH heterostructures and their efficient photocatalytic activity for RhB degradation.

We have demonstrated the synthesis of Ag3PO4/LaCO3OH (APO/LCO) heterostructured photocatalysts by an in situ wet chemical method. From pre-screening evaluations of photocatalysts with APO/(x wt% LCO) composites with mass ratios of x = 5, 10, 15, 20, 25 and 30 wt%, we found that the APO/LCO (20 wt%) exhibited a superior photocatalytic activity for organic pollutant remediation. Therefore, an optimised photocatalyst APO/LCO (20 wt%) is selected for the present study and we investigate the effect of a mixed solvent system (H2O:THF) on the morphology, which has a direct effect on the photocatalytic performance. Interestingly, a profound effect on the morphological features of APO/LCO20 heterostructures was observed with variation in the ratio of the solvent system. From the FESEM study it is observed that the LCO spherical nanoparticles are transformed into nanorods with the variation of THF into the solvent system. Moreover, these LCO nanorods make intimate contact with the APO microstructures which is helpful for the improvement of the photocatalytic activity. The photocatalytic activities of the APO/LCO composites with different solvent ratios were evaluated by the degradation of rhodamine B (RhB) under visible light irradiation. Excellent photocatalytic activity was observed for the APO/LCO-2 (H2O : THF = 60 : 40) sample. This might be due to uniform covering of the APO microstructures by fine LCO rod-like structures offering intimate contact between the APO and LCO and providing proper channels for the degradation reactions. Furthermore, with an increasing THF volume ratio in the reaction system there was an increase of the dimensions of the LCO rod-like structures and also a loose compactness of their uniform intimate contact between the APO/LCO heterostructures. All in all, the enhanced photocatalytic activity of the APO/LCO heterostructures is attributed to the collective co-catalytic effect of LCO, by providing accelerated charge separation through the heterojunction interface, and THF, by helping to tune the unique morphological features which eventually facilitate the photocatalysis process.

Unique perforated graphene derived from Bougainvillea flowers for high-power supercapacitors: a green approach.

Herein, we demonstrated a green approach for the synthesis of high surface area (850 m2 g-1) mesoporous perforated graphene (PG) from Bougainvillea flower for the first time using a template free single-step method. The existence of PG was confirmed by XRD, Raman spectroscopy, FESEM, and FETEM. Surprisingly, FETEM clearly showed 5-10 nm perforation on the graphene sheets. More significantly, these mesoporous perforated graphene sheets can be produced in large scale using the present green approach. Considering high surface area and unique perforated graphene architecture, these PGs were studied for supercapacitor applications in detail without any chemical or physical activation. The nanoporosity and high conductivity of PG derived from Bougainvillea flower exhibited excellent supercapacitive performance. According to the supercapacitor study, the synthesized perforated graphene sheets conferred a very high specific capacitance of 458 F g-1 and an energy density of 63.7 Wh kg-1 at the power density of around 273.2 Wh kg-1 in aqueous 1 M Na2SO4. Significantly, the areal capacitance of PG was observed to be very high, i.e. 67.2 mF cm-2. The cyclability study results showed excellent stability of synthesized perforated graphene sheets up to 10 000 cycles. Note that the specific and areal capacitance and the energy density of the synthesized PGs are much higher than the earlier reported values. The high supercapacitive performance may be due to high surface area and mesoporosity of PG. The present approach has a good potential to produce cheaper and high surface area PG. These PGs are good candidates as an anode material in the lithium-ion battery.

Template Free Architecture of Hierarchical Nanostructured ZnIn2S4 Rose-Like Flowers for Solar Hydrogen Production.

We have demonstrated the controlled synthesis of hierarchical nanostructured ZnIn2S4 using a facile template free hydrothermal/solvothermal method. The effect of solvents on the morphology and microstructure of ZnIn2S4 has been studied by using water, methanol and ethylene glycol as a solvents. The hierarchical nanostructure, i.e., rose-like morphology composed of very thin (5­6 nm) nanoplates of length ˜1 µm which was obtained in aqueous mediated ZnIn2S4. The porous structure (distorted flowers) and agglomerated nanoparticles were obtained using methanol-and ethylene glycol-mediated ZnIn2S4. Considering the band gap in the visible region, ZnIn2S4 is used as a solar light driven photocatalyst. An ecofriendly photocatalytic process for the conversion of poisonous H2S into H2 which is a green unconventional energy source has been demonstrated. The nanostructured ZnIn2S4 is employed as a photocatalyst for hydrogen production from H2S via a solar light-driven eco-friendly approach. The stable photocatalytic activity of hydrogen evolution, i.e., 3964 µmol ⁻¹ was obtained using 0.5 gm of such hierarchical nanostructured ZnIn2S4 under visible light irradiation. The unique hierarchical nanostructured ZnIn2S4 ternary semiconductor having hexagonal layer is expected to have potential applications in solar cells, LEDs, charge storage, electrochemical recording, thermoelectricity, other prospective electronic and optical devices.

Nanostructured CdS sensitized CdWO4 nanorods for hydrogen generation from hydrogen sulfide and dye degradation under sunlight.

In this report, CdS nanoparticles have been grown on the surface of CdWO4 nanorods via an in-situ approach and their high photocatalytic ability toward dye degradation and H2 evolution from H2S splitting under visible light has been demonstrated. The structural and optical properties as well as morphologies with varying amount of CdS to form CdS@CdWO4 have been investigated. Elemental mapping and high resolution transmission electron microscopy (HRTEM) analysis proved the sensitization of CdWO4 nanorods by CdS nanoparticles. A decrease in the PL emission of CdWO4 was observed with increasing amount of CdS nanoparticles loading possibly due to the formation of trap states. Considering the band gap in visible region, the photocatalytic study has been performed for H2 production from H2S and dye degradation under natural sunlight. The steady evolution of H2 was observed from an aqueous H2S solution even without noble metal. Moreover, the rate of photocatalytic H2 evolution over CdS modified CdWO4 is ca. 5.6 times higher than that of sole CdWO4 under visible light. CdS modified CdWO4 showed a good ability toward the photo-degradation of methylene Blue. The rate of dye degradation over CdS modified CdWO4 is ca. 7.4 times higher than that of pristine CdWO4 under natural sunlight. With increase in amount of CdS nanoparticle loading on CdWO4 nanorods the hydrogen generation was observed to be decreased where as dye degradation rate is increased. Such nano-heterostructures may have potential in other photocatalytic reactions.

Magnetically separable Ag3PO4/NiFe2O4 composites with enhanced photocatalytic activity.

Magnetically separable Ag3PO4/NiFe2O4 (APO/NFO) composites were prepared by an in situ precipitation method. The photocatalytic activity of photocatalysts consisting of different APO/NFO mass ratios was evaluated by degradation of methylene blue (MB) under visible light irradiation. The excellent photocatalytic activity was observed using APO/NFO5 (5% NFO) composites with good cycling stability which is higher than that of pure Ag3PO4 and NiFe2O4. All the APO/NFO composites showed good magnetic behavior, which makes them magnetically separable after reaction and reusable for several experiments. Photoconductivities of pure and composite samples were examined to study the photoresponse characteristics. The current intensity greatly enhanced by loading NFO to APO. Furthermore, the photocatalytic performance of the samples is correlated with the conductivity of the samples. The enhancement in the photocatalytic activity of APO/NFO composites for MB degradation is attributed to the excellent conductivity of APO/NFO composites through the co-catalytic effect of NFO by providing accelerated charge separation through the n-n interface.

Polymethyl methacrylate (PMMA)-bismuth ferrite (BFO) nanocomposite: low loss and high dielectric constant materials with perceptible magnetic properties.

Herein, poly(methyl methacrylate)-bismuth ferrite (PMMA-BFO) nanocomposites were successfully prepared by an in situ polymerization method for the first time. Initially, the as prepared bismuth ferrite (BFO) nanoparticles were dispersed in the monomer, (methyl methacrylate) by sonication. Benzoyl peroxide was used to initiate the polymerization reaction in ethyl acetate medium. The nanocomposite films were subjected to X-ray diffraction analysis (XRD), (1)H NMR, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), infrared spectroscopy (IR), dielectric and magnetic characterizations. The dielectric measurement of the nanocomposites was investigated at a frequency range of 10 Hz to 1 MHz. It was found that the nanocomposites not only showed a significantly increased value of the dielectric constant with an increase in the loading percentage of BFO as compared to pure PMMA, but also exhibited low dielectric loss values over a wide range of frequencies. The values of the dielectric constant and dielectric loss of the PMMA-BFO5 (5% BFO loading) sample at 1 kHz frequency was found be ~14 and 0.037. The variation of the ferromagnetic response of the nanocomposite was consistent with the varying volume percentage of the nanoparticles. The remnant magnetization (Mr) and saturation magnetization (Ms) values of the composites were found to be enhanced by increasing the loading percentage of BFO. The value of Ms for PMMA-BFO5 was found to be ~6 emu g(-1). The prima facie observations suggest that the nanocomposite is a potential candidate for application in high dielectric constant capacitors. Significantly, based on its magnetic properties the composite will also be useful for use in hard disk components.

Nanostructured N-doped TiO2 marigold flowers for an efficient solar hydrogen production from H2S.

Nitrogen-doped TiO2 nanostructures in the form of marigold flowers have been synthesized for the first time using a facile solvothermal method. The structural analysis has shown that such an N-doped TiO2 system crystallizes in the anatase structure. The optical absorption spectra have clearly shown the shift in the absorption edge towards the visible-light range, which indicates successful nitrogen doping. The nitrogen doping has been further confirmed by photoluminescence and photoemission spectroscopy. Microscopy studies have shown the thin nanosheets (petals) of N-TiO2 with a thickness of ∼2-3 nm, assembled in the form of the marigold flower with a high surface area (224 m(2) g(-1)). The N-TiO2 nanostructure with marigold flowers is an efficient photocatalyst for the decomposition of H2S and production of hydrogen under solar light. The maximum hydrogen evolution obtained is higher than other known N-TiO2 systems. It is noteworthy that photohydrogen production using the unique marigold flowers of N-TiO2 from abundant H2S under solar light is hitherto unattempted. The proposed synthesis method can also be utilized to design other hierarchical nanostructured N-doped metal oxides.

Silver-decorated orthorhombic nanotubes of lithium vanadium oxide: an impeder of bacterial growth and biofilm.

Reoccurrence of infectious diseases and ability of pathogens to resist antibacterial action has raised enormous challenges which may possibly be confronted by nanotechnology routes. In the present study, uniformly embedded silver nanoparticles in orthorhombic nanotubes of lithium vanadium oxide (LiV2O5/Ag) were explored as an impeder of bacterial growth and biofilm. The LiV2O5/Ag nanocomposites have impeded growth of Gram-positive Bacillus subtilis NCIM 2063 and Gram-negative Escherichia coli NCIM 2931 at 60 to 120 µg/mL. It also impeded the biofilm in Pseudomonas aeruginosa NCIM 2948 at 12.5 to 25 µg/mL. Impedance in the growth and biofilm occurs primarily by direct action of the nanocomposites on the cell surfaces of test organisms as revealed by surface perturbation in scanning electron microscopy. As the metabolic growth and biofilm formation phenomena of pathogens play a central role in progression of pathogenesis, LiV2O5/Ag nanocomposite-based approach is likely to curb the menace of reoccurrence of infectious diseases. Thus, LiV2O5/Ag nanocomposites can be viewed as a promising candidate in biofabrication of biomedical materials.

Template-free synthesis of nanostructured Cd(x)Zn(1-x)S with tunable band structure for H2 production and organic dye degradation using solar light.

We have demonstrated a template-free large-scale synthesis of nanostructured Cd(x)Zn(1-x)S by a simple and a low-temperature solid-state method. Cadmium oxide, zinc oxide, and thiourea in various concentration ratios are homogenized at moderate temperature to obtain nanostructured Cd(x)Zn(1-x)S. We have also demonstrated that phase purity of the sample can be controlled with a simple adjustment of the amount of Zn content and nanocrystalline Cd(x)Zn(1-x)S(x = 0.5 and 0.9) of the hexagonal phase with 6-8 nm sized and 4-5 nm sized Cd(0.1)Zn(0.9)S of cubic phase can be easily obtained using this simple approach. UV-vis and PL spectrum indicate that the optical properties of as synthesized nanostructures can also be modulated by tuning their compositions. Considering the band gap of the nanostructured Cd(x)Zn(1-x)S well within the visible region, the photocatalytic activity for H2 generation using H2S and methylene blue dye degradation is performed under visible-light irradiation. The maximum H2 evolution of 8320 µmol h(-1)g(-1) is obtained using nanostructured Cd(0.1)Zn(0.9)S, which is four times higher than that of bulk CdS (2020 µmol h(-1) g(-1)) and the reported nanostructured CdS (5890 µmol h(-1)g(-1)). As synthesized Cd(0.9)Zn(0.1)S shows 2-fold enhancement in degradation of methylene blue as compared to the bulk CdS. It is noteworthy that the synthesis method adapted provides an easy, inexpensive, and pollution-free way to synthesize very tiny nanoparticles of Cd(x)Zn(1-x)S with a tunnable band structure on a large scale, which is quite difficult to obtain by other methods. More significantly, environmental benign enhanced H2 production from hazardous H2S using Cd(x)Zn(1-x)S is demonstrated for the first time.

Evaluation of anti-quorum sensing activity of silver nanowires.

A menace of antimicrobial resistance with growing difficulties in eradicating clinical pathogens owing to the biofilm has prompted us to take up a facile aqueous-phase approach for the synthesis of silver nanowires (SNWs) by using ethylene glycol as a reducing agent and polyvinylpyrrolidone (PVP) as a capping agent. This synthesis is a reflux reaction seedless process. The obtained SNWs were about 200-250 nm in diameter and up to 3-4 µm in length. The SNWs were characterized by field emission scanning electron microscopy, transmission electron microscopy, UV-Vis spectroscopy, and X-Ray powder diffraction, and the chemical composition of the sample was examined by energy dispersive X-ray spectrum. The SNWs did not show an antibacterial activity against test organisms, Bacillus subtilis NCIM 2063 and Escherichia coli NCIM 2931; however, it showed a promising property of a quorum sensing-mediated inhibition of biofilm in Pseudomonas aeruginosa NCIM 2948 and violacein synthesis in Chromobacterium violaceum ATCC 12472, which is hitherto unattempted, by polyol approach.

Nanowires of silver-polyaniline nanocomposite synthesized via in situ polymerization and its novel functionality as an antibacterial agent.

Silver-polyaniline (Ag-PANI) nanocomposite was synthesized by in situ polymerization method using ammonium persulfate (APS) as an oxidizing agent in the presence of dodecylbenzene sulfonic acid (DBSA) and silver nitrate (AgNO(3)). The as synthesized Ag-PANI nanocomposite was characterized by using different analytical techniques such as UV-visible (UV-vis) and Fourier transform Infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV-visible spectra of the synthesized nanocomposite showed a sharp peak at ~420 nm corresponding to the surface plasmon resonance (SPR) of the silver nanoparticles (AgNPs) embedded in the polymer matrix which is overlapped by the polaronic peak of polyaniline appearing at that wavelength. Nanowires of Ag-PANI nanocomposite with diameter 50-70 nm were observed in FE-SEM and TEM. TGA has indicated an enhanced thermal stability of nanocomposite as compared to that of pure polymer. The Ag-PANI nanocomposite has shown an antibacterial activity against model organisms, a gram positive Bacillus subtilis NCIM 6633 in Mueller-Hinton (MH) medium, which is hitherto unattempted. The Ag-PANI nanocomposite with monodispersed AgNPs is considered to have potential applications in sensors, catalysis, batteries and electronic devices.

Nanocrystalline zinc indium vanadate: a novel photocatalyst for hydrogen generation.

Hydrogen is a future fuel and hence production of cheap hydrogen is an important area of research. Recently, the photocatalysts were used to generate hydrogen from water and hydrogen sulfide splitting under solar light. Hence, we designed Zinc Indium Vanadate, a novel visible light active photocatalyst and used for the generation of hydrogen by using solar light. We have demonstrated the synthesis of ZnIn2V2O9 (ZIV) catalyst by sonochemical route using NH4VO3, In (NO3)3 and Zn(CH3COO)2 as a precursors and PVP as a capping agent. The obtained product was further characterized by XRD, UV-DRS and FESEM. The XRD pattern reveals the existence of monoclinic crystal structure and broader peaks indicating the nanocrystalline nature of the material. The particle size was observed in the range of 50-70 nm. The optical study showed the absorption edge cut off at 520 nm with estimated band gap about 2.3 eV. Considering the band gap in visible range, ZnIn2V2O9 was used as a photocatalyst for photodecomposition of H2S under visible light irradiation to produce hydrogen. We observed excellent photocatalytic activity for the hydrogen generation by using this photocatalyst.