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A visible light active photocatalyst, Ag/TiO 2 /MWCNT was synthesized by loading of Ag nanoparticles onto TiO 2 /MWCNT nanocomposite. The photocatalytic activity of Ag/TiO 2 /MWCNT ternary nanocomposite was evaluated for the degradation of methylene blue dye under UV and visible light irradiation. Ag/TiO 2 /MWCNT ternary nanocomposite exhibits (~9 times) higher photocatalytic activity than TiO 2 /MWCNT and (~2 times) higher than Ag/TiO 2 binary nanocomposites under visible light irradiation. The enhancement in the photocatalytic activity is attributed to the synergistic effect between Ag nanoparticles and MWCNT, which enhance the charge separation efficiency by Schottky barrier formation at Ag/TiO 2 interface and role of MWCNT as an electron reservoir. Effect of different scavengers on the degradation of methylene blue dye in the presence of catalyst has been investigated to find the role of photogenerated electrons and holes. Simultaneously, the Ag/TiO 2 /MWCNT shows excellent photocatalytic stability. This work highlights the importance of Ag/TiO 2 /MWCNT ternary nanocomposite as highly efficient and stable visible-light-driven photocatalyst for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Thin films of YBCO and YBCO:BaZrO (BZO) nanocomposite have been deposited using the pulsed laser deposition technique. Substantial increase in critical current density ( J) and pinning force density ( F) of the nanocomposite thin films was observed. The possible pinning mechanism in YBCO:BZO nanocomposite thin films has been explored and compared with the pinning mechanism in pure YBCO thin film by studying the variation of J with magnetic field ( B) and temperature. In the intermediate field regime (0.1-1 T), J follows B with nearly similar values of α for YBCO and YBCO:BZO nanocomposite thin films indicating similar pinning mechanism in both thin films. The variation of J with reduced temperature ( t= T/ T) has been studied for both the films and it was observed that the mechanism of pinning in both YBCO and YBCO:BZO thin films is similar ( δT pinning). The observed enhanced values of J and F of the nanocomposite thin film is attributed to the presence of BZO nanoparticles, which induces more defects due to lattice mismatch between YBCO and BZO leading to improved flux pinning properties of the nanocomposite thin film. [ABSTRACT FROM AUTHOR]

Abstract: YBa2Cu3O7−δ–BaTiO3 (4wt.%) (YBCO–BTO (4%)) composite bulk polycrystalline sample has been synthesized by solid state reaction method. The structure of composite sample has been investigated by X-ray diffraction and magnetization measurements were carried out using MPMS SQUID VSM. The superconducting transition temperature of the YBCO–BTO (4%) sample was similar to that of pure YBCO. The critical current density (Jc ) for YBCO–BTO (4%) sample increases significantly as compared to pure YBCO sample. The enhancement of the critical current density in the YBCO–BTO (4%) sample has been attributed to the presence of BaTiO3 nanoparticles acting as artificial pinning centres. The introduction of BaTiO3 particles in YBCO increases pinning force density from 0.71GN/m2 to 1.41GN/m2 at 4K and 0.33MN/m2 to 0.97MN/m2 at 77K. [Copyright &y& Elsevier]

[Display omitted] • Reflux method has been used to synthesize RGO/NaNbO 3 -NRs nanocomposite. • Incorporation of RGO with NaNbO 3 -NRs greatly enhanced photocatalytic and PEC activity. • RGO/NaNbO 3 -NRs photoanode exhibited ∼3-fold enhancement of IPCE than that of NaNbO 3 -NRs. In this present work, reduced graphene oxide (RGO) coupled with hydrothermally grown sodium niobate nanorods (NaNbO 3 -NRs) have been successfully synthesized. The photocatalytic performance of RGO/NaNbO 3 -NRs photocatalyst demonstrated faster photodegradation of organic methylene blue (MB) dye than bare NaNbO 3 -NRs. A ∼6 fold enhancement in the photocatalytic activity of RGO/NaNbO 3 -NRs nanocomposite than that of NaNbO 3 -NRs has been demonstrated towards the degradation of MB dye under similar light illumination. Furthermore, the potentiality of the fabricated NaNbO 3 -NRs and RGO/NaNbO 3 -NRs nanocomposite photoanodes have been investigated for photoelectrochemical (PEC) water splitting. The fabricated RGO/NaNbO 3 -NRs nanocomposite photoanode showed ∼4 times higher photocurrent density than the NaNbO 3 -NRs photoanode. The electrochemical impedance spectroscopy (EIS) and Mott-Schottky (MS) measurements demonstrated that coupling of RGO nanosheets in the RGO/NaNbO 3 -NRs nanocomposite reduced the charge transfer resistance (R ct) at the photoanode/electrolyte interface, increased the donor density (N d), and reduced flat band potential (V fb) of the RGO/NaNbO 3 -NRs, thus significantly improving the PEC performance of the RGO/NaNbO 3 -NRs nanocomposite. The enhancement in the PEC measurements of RGO/NaNbO 3 -NRs nanocomposite is attributed to the extended absorption of the visible portion of the solar spectra and increased mobility of the photogenerated charge transport in the RGO nanosheets, which improve the separation efficiency and reduce the recombination process. The possible charge transfer mechanism has been proposed responsible for the enhanced photocatalytic and PEC water splitting performance. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) coupled Zinc oxide (ZnO) nanocomposite has been synthesized by the chemisorption method and demonstrated its potential applications for photocatalytic degradation of methylene blue dye and photoelectrochemical (PEC) water splitting. A ∼7 fold enhancement in the photodegradation activity and ∼3 fold enhancement in the incident photon-to-electron conversion efficiency is observed for PANI/ZnO nanocomposite as compared to bare ZnO nanorods. The observed enhancement in the photocatalytic and photoelectrochemical activity is attributed to the photosensitization effect of visible light responsive PANI and the formation of type-II heterojunction between ZnO and PANI leading to the efficient separation and faster transfer of photoinduced charge carriers at the interface. A possible mechanism for the enhanced photocatalytic activity and photoelectrochemical water splitting for PANI/ZnO nanocomposite has been proposed. [ABSTRACT FROM AUTHOR]

• The PVDF, PVDF-MoS 2 , and PVDF-rGO-MoS 2 nanocomposites were fabricated by the polymer solution casting method. • The synthesized materials and thin films were examined using XRD, FTIR, and PFM techniques. • The fabricated piezoelectric nanogenerator of MoS 2 -rGO-PVDF nanocomposite showed enhanced output current and voltage. [Display omitted] Piezoelectric materials can make substantial contributions to resolve the overall energy crisis by providing a renewable energy solution. With the present increase in the number of microscale devices, piezoelectric power generation can provide an appropriate alternative to conventional power sources for low powered electronic devices. In this study, Flexible PVDF, PVDF-MoS 2 , and PVDF-rGO-MoS 2 thin films were prepared by polymer solution casting method and their piezoelectric properties are explored. The structural and morphological characteristics of the synthesized materials and thin films were examined using XRD, FTIR, and PFM techniques. The fabricated flexible film is encapsulated with an insulating layer so that when we tap the device, the electrodes are not affected. The flexible thin film of PVDF-rGO-MoS 2 has significantly improved generated voltage which is ~5 times higher than the flexible film of PVDF and ~2 times higher than PVDF-MoS 2 flexible film. The mechanism involved in the improved piezoresponse of the flexible thin film was also proposed. [ABSTRACT FROM AUTHOR]

• 3D hierarchical Bi 2 S 3 nanoflowers synthesized by hydrothermal route. • Implementation of a facile and low cost two-step procedure to synthesize PANI/Bi 2 S 3 nanocomposite at RT. • Rational design and fabrication of 3D hierarchical PANI/Bi 2 S 3 photoanode for visible light induced PEC water splitting. • Demonstration of ~5 fold increased photocurrent density by PANI/Bi 2 S 3 than that of Bi 2 S 3 photoanode. • Enhanced PEC performance achieved due to staggered Type-II heterojunction and faster charge transport. ga1 The fabrication of the semiconductor photoanode with good chemical stability, sufficient light harvesting ability, and fast charge carrier separation and transportation capability is crucial for efficient photoelectrochemical (PEC) water splitting. Herein, we designed the nanocomposite based photoelectrode which is integrated by hydrothermally grown 3D hierarchical nanoflowers (NFs) of bismuth sulfide (Bi 2 S 3) and conducting polymer polyaniline (PANI). The as-fabricated PANI/Bi 2 S 3 photoanode has demonstrated much enhanced photocurrent density (~6.95 mA/cm2 at 0.8 V vs. NHE), which is ~5 fold higher in comparison to Bi 2 S 3 photoanode (~1.30 mA/cm2 at 0.8 V vs. NHE). Also, the PANI/Bi 2 S 3 photoanode has exhibited profoundly increased charge separation and injection efficiency of ~78.31% and ~90.18%, respectively. Furthermore, ~3 fold increased incident photon-to-current conversion efficiency (IPCE) value is achieved by PANI/Bi 2 S 3 as compared to the Bi 2 S 3 photoanode. The rational design of hierarchical semiconductor heterojunction, improved visible light absorption, efficient separation of photogenerated charge carriers, and faster charge transport properties altogether account for the enhanced PEC performance of the fabricated PANI/Bi 2 S 3 photoanode. A possible schematic model for the significantly enhanced activity of the PANI/Bi 2 S 3 photoanode for solar light induced PEC water splitting has also been explicated. These findings would provide new opportunities for understanding, exploration, and advancement of different other novel 3D hierarchical nanostructures based systems in the area of energy conversion, harvesting, and storage in the future. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2), a transition metal dichalcogenides (TMDs) is a potential candidate for thermoelectric due to its inherent low thermal conductivity. However, its low electrical conductivity confines its practical usage. In this paper, we have synthesized nanocomposite of MoS 2 with reduced graphene oxide (RGO) and demonstrated a ∼5920% increase in the thermoelectric figure of merit of MoS 2 after formation of MoS 2 -RGO nanocomposite. This ultra-high enhanced thermoelectric figure of merit is due to significantly enhanced electrical conductivity, increased Seebeck effect and simultaneous reduction of thermal conductivity of MoS 2 in the MoS 2 -RGO nanocomposite. Presence of RGO in the matrix of MoS 2 in MoS 2 -RGO nanocomposite provides conducting path, reduces interface barrier height and also provides enhanced scattering of phonons. • MoS 2 -RGO nanocomposite has been synthesized by reflux method. • Structural characterizations of MoS 2 -RGO nanocomposite have been done. • MoS 2 is a potential candidate for thermoelectric Application. [ABSTRACT FROM AUTHOR]

The elevated concentration of heavy metal ions poses severe challenges to environmental homeostasis and human health. Although significant efforts have been made towards the development of heavy metal ion sensors with varying degrees of success, these sensors are largely tailored for, and hence limited to, the detection of a single metal ion. Here we present a novel fluorescence-based sensor featuring polyindole/cadmium sulphide (PIN/CdS) nanocomposite that uniquely detects the presence and concentration of three important heavy metal ions, namely chromium (Cr 3+ ), iron (Fe 3+ ) and tin (Sn 2+ ). The PIN/CdS nanocomposite was found to be an excellent receptor for the target ions via significant fluorescent enhancement owing to the inhibition of internal charge transfer (ICT) process and an efficient chelation enhanced fluorescence (CHEF) effect. A linear relationship between fluorescence intensity and Cr 3+ , Fe 3+ and Sn 2+ concentrations was obtained. Importantly, no interference was observed from 17 other commonly tested metal ions thereby making it a highly selective, yet multiplexed, probe for detection of these three ions. Finally, the sensor was used to detect and quantify aforementioned ions in routine drinking water samples. The multiplexed sensing ability and remarkable functional reversibility coupled with its straightforward synthesis and easy-to-use characteristics make this sensor particularly attractive for environmental and biomedical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple chemisorption method was used to synthesize H-ZIS/CN nanocomposites. • H-ZIS/CN nanocomposites exhibits ∼ 1.9 times higher photocurrent density compared to ZIS photoanode. • A ∼ 8.5 % incident photon to current conversion efficiency (IPCE) was achieved for H-ZIS/CN nanocomposites. Hexagonal zinc indium sulfide coupled g-C 3 N 4 (H-ZnIn 2 S 4 /g-C 3 N 4) nanocomposites were synthesized using chemisorption method and its performance towards photoelectrochemical water splitting activity was studied. The H-ZnIn 2 S 4 /g-C 3 N 4 (H-ZIS/CN) nanocomposites exhibited ∼ 1.9 times enhanced photoelectrochemical performance as compared to the H-ZnIn 2 S 4. The enhancement in the PEC water splitting activity of H-ZIS/CN nanocomposite is ascribed to the formation of type-II heterojunction which resulted in improved separation of photogenerated charge carriers and faster transfer of charges at the photoelectrode/electrolyte interface. The electrochemical impedance study and Mott-Schottky supported these results. Moreover, during photoelectrochemical reactions, H-ZIS/CN nanocomposites showed tremendous stability under visible light. A potential mechanism of the enhanced photoelectrochemical activity of H-ZIS/CN nanocomposites was proposed and endorsed by the PEC results. This study demonstrates that establishing a heterostructure system by coupling a ternary chalcogenide semiconductor with a conducting polymer is an effective strategy for PEC water splitting applications. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis of ZnO/MWCNT nanocomposite, and their potential application in photoelectrochemical (PEC) water splitting for hydrogen generation and photocatalytic degradation of methylene blue dye. For the synthesis of nanocomposite, ZnO nanoparticles were grown on the MWCNT surface by a simple chemical route. Microscopic studies showed that ZnO nanoparticles were well dispersed on the MWCNT surface and Raman study confirmed the intimate integration between ZnO and MWCNT. The nanocomposite exhibit higher photocatalytic degradation of methylene blue dye as compared to bare ZnO. The ZnO/MWCNT photoanode shows ∼5 times increase in photocurrent density in comparison to pure ZnO, at an applied potential of +1 V vs. Ag/AgCl. The enhanced photocurrent density of ZnO/MWCNT photoanode is attributed to the decrease in band-bending and effective interfacial electron transfer due to the conducting CNT scaffold, which facilitates the charge collection and charge transport in the ZnO/MWCNT nanocomposite. The Electrochemical impedance spectroscopy measurements confirmed the faster charge transfer at the interface in the case of nanocomposite. These results suggest substantial potential of ZnO/MWCNT nanocomposite in dye degradation and PEC water splitting applications. [ABSTRACT FROM AUTHOR]

A ternary Ag/TiO 2 /CNT photoanode was prepared by grafting Ag nanoparticles on the surface of as-synthesized TiO 2 /CNT nanocomposite for the photoelectrochemical (PEC) water splitting under visible light irradiance. The ternary composite photoanode was observed to generate four times higher photocurrent density compared to binary TiO 2 /CNT nanocomposite under visible light irradiance. The Ag nanoparticles on the surface of nanocomposite act as a surface plasmon resonance (SPR) photosensitizer under visible light. The enhanced photocurrent density of Ag/TiO 2 /CNT ternary photoanode is attributed to the increased light absorption in the visible region, decrease in band-bending and effective interfacial electron transfer due to the synergetic effect of Ag nanoparticles and CNTs. The enhanced charge transfer within the Ag/TiO 2 /CNT was also confirmed by the electrochemical impedance spectroscopy. This work demonstrates a feasible route to improve the PEC performance of TiO 2 towards water splitting under sunlight irradiation. [ABSTRACT FROM AUTHOR]