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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: The effect of incorporation of BaTiO3(BTO) nanoparticles on the flux pinning properties of pulsed laser deposited YBCO:BTO thin films was studied. Substantial increase in the critical current density () and the pinning force density () of the nanocomposite thin films was observed. At 77 K, and zero applied magnetic field, the value of for YBCO and YBCO:BTO (2%) thin films were 2.93 MA/cm2 and 6.43 MA/cm2, respectively. At the same temperature and an applied magnetic field of 4 T, the value of increases from 3.6×104 A/cm2 for YBCO thin film to 2.7×105 A/cm2 for YBCO:BTO (2%) nanocomposite thin film. The study of temperature and field dependence of of YBCO and YBCO:BTO thin films indicates similar type of pinning. The lattice mismatch between YBCO and BTO seems to introduce more defects resulting in the improvement of flux pinning properties. [Copyright &y& Elsevier]

Flexible piezoelectric nanogenerator (PENG) using a poly(vinylidene fluoride)–cobalt ferrite (PVDF–CFO) nanocomposite film is prepared in which the output power of the PENG device can be tuned by the application of an external magnetic field. Ferromagnetic CFO nanoparticles were prepared by the hydrothermal method and are incorporated in the PVDF matrix using the drop casting technique. The presence of CFO in the PVDF matrix enhances the ferroelectric β phase fraction of PVDF from 59% to 75% and also provides magnetic tunability to the PENG device. With the application of a 2.1 kG field, there is 2.33 times increment in instantaneous output power of the PENG, which is attributed to a decrease in the resistance of the nanocomposite film due to the alignment of the magnetic moment of CFO nanoparticles leading to a reduction in the scattering of mobile charges. These outcomes open up a possibility in piezomagnetotronic materials through the realization of magneto-sensitive multifunctional PENGs, which can be scaled up for fabricating compact, high-performance, portable devices for smart sensor applications. [ABSTRACT FROM AUTHOR]

[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]

Metal oxide as a thermoelectric material has shown great attention in recent years due to its outstanding thermal and chemical stability, good oxidation resistance, low cost, etc. This article reports the successful synthesis of tungsten oxide (WO 3) nanoparticles and tungsten oxide-reduced graphene oxide (WO 3 -rGO) nanocomposites and studies of their thermoelectric properties. The structural characteristics of the WO 3 nanoparticles and WO 3 -rGO nanocomposites were examined using XRD and Raman techniques. At 313 K, WO 3 -rGO nanocomposites exhibit an ~ 8.8 times enhancement in the thermoelectric material figure of merit (zT). These excellent performances are further supported by up to ~ 13.7 times enhanced electrical conductivity and a ~ 56% reduction in thermal conductivity compared to WO 3 nanoparticles. It has been concluded that reduce graphene oxide helps in forming a conducting pathway in the WO 3 -rGO nanocomposites, allowing the easy passage of charge carriers in the matrix. [ABSTRACT FROM AUTHOR]

Silver (Ag) nanoparticles decorated NaNbO 3 nanorods (Ag-NaNbO 3) based nanocomposite have been successfully synthesized by simple chemical solution method with the aim to couple the plasmonic and piezo-phototronic effect. The Ag-NaNbO 3 nanocomposite showed much enhanced photocatalytic and photoelectrochemical water splitting properties as compared to bare NaNbO 3. A ∼10 fold enhancement in the photodecomposition of organic MB dye and a ∼9 fold increment in the photocurrent density of photoelectrochemical water splitting was observed as compared to bare NaNbO 3 , which has been attributed to the combined plasmonic and piezo-phototronic effect. The plasmonic effect due to the presence of Ag nanoparticles on the NaNbO 3 surface resulted in enhanced absorption of visible light and piezo-photoelectric effect resulted in better separation of the photogenerated charges due to the built-in electric field. This approach demonstrates a novel strategy for enhancing the performance of silver decorated semiconducting/piezoelectric material for achieving efficient photocatalytic dye degradation and PEC water splitting. Image 1 • Piezoelectric NaNbO 3 and Plasmonic Ag-NaNbO 3 nanocomposites have been synthesized. • Ag-NaNbO 3 exhibited higher photocatalytic and PEC activity as compared to NaNbO 3. • Enhancement is attributed to the coupling of piezo-phototronic and plasmonic effect. • Mechanism of charge transfer process for Ag-NaNbO 3 nanocomposite was proposed. [ABSTRACT FROM AUTHOR]

Hierarchical nanoflowers (NFs) of zinc oxide (ZnO) have been synthesized in the hexagonal wurtzite structure by a facile hydrothermal method. Polyaniline (PANI) has been prepared by the chemical oxidative polymerization method and incorporated with ZnO NFs by the chemisorption method. The potential of the synthesized nanostructures has been demonstrated for efficient photocatalytic degradation of methylene blue (MB) and photoelectrochemical water splitting. The PANI/ZnO nanocomposite has exhibited the enhanced photocatalytic activity which is ∼9 fold higher in comparison to pristine ZnO NFs and enhanced photocurrent density which is ∼16 fold higher than the ZnO photoanode. Importantly, ∼4 fold increment in the incident photon-to-current conversion efficiency (IPCE) is exhibited by PANI/ZnO, than that of ZnO photoanode. The remarkably enhanced photocatalytic and photoelectrochemical performance of PANI/ZnO nanocomposite is attributed to the availability of more interfacial sites facilitated by the hierarchical ZnO NFs, improved overall photoresponse due to its photosensitization with PANI and the resulting type-II heterojunction between them, which helps in the efficient separation of photogenerated charge carriers at the interface. A plausible reaction mechanism for the substantially improved performance of nanostructured PANI/ZnO towards MB degradation and water splitting has also been elucidated. [ABSTRACT FROM AUTHOR]

Developing photoanode with proficient sunlight harvesting, stability as well as enhancing the electron injection across the interface remains a major challenge in the photoelectrochemical water splitting strategy to generate hydrogen. Herein, we design and fabricate an organic/inorganic TiO 2 /C 3 N 4 /CNT photoanode by a hydrothermal technique which exhibits much enhanced photoelectrochemical properties. The TiO 2 /C 3 N 4 /CNT photoanode exhibits a photocurrent density of 2.94 mA/cm2, which is ~6.4 time higher than pristine graphitic carbon nitride (C 3 N 4) at an applied bias potential of 0.6 V vs. Ag/AgCl. The excellent photoelectrochemical performance benefits from the impactful migration of photo-induced electrons at the TiO 2 /C 3 N 4 interface from C 3 N 4 to TiO 2 and their intimate interface contact with CNT. Kelvin probe force microscopy result shows a smaller interface barrier height (~10 meV) between TiO 2 and C 3 N 4 , suggesting that electrons transport is favored through TiO 2 /C 3 N 4 interfaces in a ternary photoanode. The TiO 2 /C 3 N 4 /CNT photoanode exhibited an onset potential of 0.25 V vs. Ag/AgCl which is much lower compared to pristine C 3 N 4. The electrochemical impedance spectroscopy results also confirmed the enhanced electron injection across the interface in a ternary photoanode. These results demonstrate a promising approach to develop a highly proficient and visible light active photoanode with excellent stability for renewable energy applications. Image 1 • An Organic/Inorganic ternary photoanode was synthesized by the hydrothermal method. • KPFM results shows that electron transport is favored through TiO 2 /C 3 N 4 interfaces. • The ternary photoanode exhibits ~6.4 time higher photocurrent density than C 3 N 4. • The ternary photoanode exhibited excellent photostability. [ABSTRACT FROM AUTHOR]

In this work, we have successfully synthesized silver nanoparticles (Ag-NPs) decorated binary PaNi/NBO nanocomposite by facile chemisorption route and demonstrated enhanced photoelectrochemical (PEC) water splitting activity. The ternary Ag/PaNi/NBO nanocomposite photoanode exhibits ∼5 fold higher current density than pristine NaNbO 3 nanofibers (NBO-NFs). The ternary Ag/PaNi/NBO photoanode exhibits a current density of 5.93 mA/cm2 at 0.9 V with respect to Ag/AgCl, whereas the pristine NBO-NFs photoanode exhibits only 0.85 mA/cm2 at 0.9 V. The improved performance is correlated to the high surface area, formation of the type-II heterojunction among PaNi and NBO-NFs and the introduction of the plasmonic behaviour of Ag-NPs as it expands the absorption of the visible part of the solar spectrum, which together decreases the recombination of charges with strong redox capability. Furthermore, the ternary Ag/PaNi/NBO photoanode showed lower charge transfer resistance (R ct) in the EIS measurements and improved incident photon to current efficiency (IPCE) of ∼31.3% which is ∼23% higher to the IPCE of bare NBO-NFs photoanode. Thus, these results suggest that the ternary Ag/PaNi/NBO nanocomposite is a promising material for PEC activity and wide practical applications. Image 1 • Ternary Ag/PaNi/NBO nanocomposites was synthesized by chemical solution route. • Ag/PaNi/NBO photoanode exhibited ∼5 fold higher photocurrent density than NBO. • The enhancement is attributed to the type-II heterojunction and plasmonic effect of Ag. • Possible charge transfer and separation mechanism of Ag/PaNi/NBO was proposed. [ABSTRACT FROM AUTHOR]

Flexible PVDF/NaNbO 3 /RGO thin films have been synthesized and its application in nanogenerator has been explored. In order to understand the effect of the addition of nanofillers NaNbO 3 and RGO in PVDF, we have also synthesized and studied PVDF/RGO and PVDF/NaNbO 3 nanocomposite films. Even though the β-phase contents are nearly same in the three nanocomposite films, it has been found that the output voltage generated from PVDF/NaNbO 3 /RGO nanocomposite film based nanogenerator is maximum (∼2.16 V) with a short circuit current of 0.383 μA. It has been concluded that NaNbO 3 nanorods help in the alignment of the electric dipoles in PVDF and also due to the inherent piezoelectric property, it contributes in the overall piezoelectric property of the film. On the other hand presence of RGO helps to move the charges generated inside the film and further allow the dipoles of PVDF to align which leads to enhanced piezoresponse. [ABSTRACT FROM AUTHOR]

In our work, zinc indium sulfide coupled polyaniline (ZnIn 2 S 4 /PANI) nanocomposites were synthesized using chemisorption method. The substantial enhancement in the photocatalytic and photoelectrochemical (PEC) water splitting activity under visible light illumination was demonstrated. ZnIn 2 S 4 /PANI nanocomposites were shown ∼3 times improvement in the photodegradation of methylene blue (MB) dye as compared to bare ZnIn 2 S 4 (ZIS) nanoflakes. In addition, the ZIS/PANI nanocomposite photoelectrode was exhibited ∼3 times enhancement in photocurrent density (∼260 μA/cm2 at 0.8 V vs. Ag/AgCl) as compared to ZnIn 2 S 4 photoelectrode. However, the ZIS/PANI photoanode was demonstrated ∼5 fold enhancement in the incident photon to current conversion efficiency (IPCE) than bare ZIS. The enhancement in the photodegradation and PEC water splitting activity of ZIS/PANI nanocomposite is ascribed to extended visible light absorption, and synergetic effect of PANI along with type-II heterojunction formation, which is beneficial for separation of charge and faster transfer efficiency of photogenerated charge carriers. This study demonstrates that establishing a heterostructure system by coupling a ternary chalcogenide semiconductor with a conducting polymer is effective for photocatalytic wastewater treatment and PEC water splitting applications. • ZnIn 2 S 4 nanoflakes were synthesized by hydrothermal method. • ZnIn 2 S 4 /PANI nanocomposites were synthesized by a simple chemisorption method. • ZnIn 2 S 4 /PANI nanocomposites shows enhanced photocatalytic activity and PEC performance. • The stability and reusability of ZnIn 2 S 4 /PANI nanocomposites were confirmed. [ABSTRACT FROM AUTHOR]

Introduction of artificial pinning centres in different morphology is a beneficial way to improve the flux pinning properties of a YBCO compound. In the present study, we report the effect of addition of sodium niobate (NaNbO 3) nanostructures in two different form i.e. nanorods (NRs) and nanoparticles (NPs) with a varied wt% (0, 0.5, and 1 wt%) on the pinning capabilities of bulk YBCO polycrystalline samples. The orthorhombic crystal structure of YBCO was confirmed by the XRD spectra even in the nanocomposite samples. The existence of NPs or NRs on the surface and between the superconducting grains of YBCO was confirmed by morphological analysis. The critical temperature (T c) remains almost unchanged as compared to pure YBCO on addition of NaNbO 3 nanostructure in YBCO compound upto 1 wt% concentration. Even at higher fields (upto 6 T) and higher temperatures (upto 75 K), the addition of NaNbO 3 NPs or NRs in YBCO nanocomposite resulted in a significant increase of ~2.6 times in the critical current density as compared to pure YBCO. In comparison to NRs added YBCO nanocomposite samples, NPs added YBCO nanocomposite samples showed higher improvement. Throughout the entire investigated range of applied field, the maximum pinning force was found for 0.5 wt% NPs added composite sample. [ABSTRACT FROM AUTHOR]

Bismuth sulfide (Bi2S3) is a promising material for thermoelectric applications owing to its non-toxicity and high abundance of bismuth (Bi) and sulfur (S) elements on earth. However, its low electrical conductivity drastically reduces the value of the figure of merit (ZT). In this work, we have synthesized three-dimensional (3D) hierarchical Bi2S3 nanoflowers (NFs) by the hydrothermal route and further incorporated them with conducting polymer polyaniline (PANI) by simple chemisorption method. We have investigated the thermoelectric properties of the as-prepared Bi2S3 NFs and PANI/Bi2S3 nanocomposite samples and it is demonstrated that the incorporation of the PANI matrix with the 3D hierarchical Bi2S3 NFs provides a conducting substrate for the easy transport of the electrons and reduces the barrier height at the interface, resulting in ∼62% increment in the electrical conductivity as compared to Bi2S3 NFs. Moreover, a decrement in the thermal conductivity of the PANI/Bi2S3 nanocomposite is observed as compared to pristine Bi2S3 NFs due to the increased phonon scattering at the interfaces facilitated by the hierarchical morphology of the NFs. Furthermore, an increment in the electrical conductivity and simultaneous decrement in the thermal conductivity results in an overall ∼20% increment in the figure of merit (ZT) for PANI/Bi2S3 nanocomposite as compared to pristine Bi2S3 NFs. The work highlights an effective strategy of coupling 3D hierarchical metal chalcogenide with conducting polymer for optimizing their thermoelectric properties. [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]

[Display omitted] • V 2 O 5 and V 2 O 5 /rGO nanocomposites were successfully synthesized by hydrothermal method. • V 2 O 5 /rGO nanocomposites shows enhanced photocatalytic activity and higher Photoelectrochemical (PEC) performance. • The higher performance of V 2 O 5 /rGO nanocomposites was achieved during PEC and photocatalytic activity due to higher charge transfer rate. In this work, we have synthesized reduced graphene oxide (rGO) coupled vanadium oxide (V 2 O 5 /rGO) nanocomposite by the simple hydrothermal route and validated its potentiality for the photodegradation of methylene blue (MB) dye and photoelectrochemical (PEC) water splitting activities. The reduction in the bandgap value of V 2 O 5 /rGO nanocomposite after coupling rGO with V 2 O 5 increases the visible light absorption property withreduced recombination rate of photogenerated charge carriers in comparison to bare V 2 O 5, which result in ∼3 fold enrichment in the photocatalytic activity. Moremore, the PEC performance of fabricated V 2 O 5 /rGO photoanode has been investigated where a ∼3.5 fold higher value of current density (1.4 mA/cm2 at 0.8 V vs. Ag/AgCl)is achieved compared to V 2 O 5 photoanode. These observations are also evident by the decreased value of charge transfer resistance at the V 2 O 5 /rGO photoanode/electrolyte interface and higher value of donor density (N d) in electrochemical impedance spectroscopy (EIS) and Mott-Schottky (MS) measurements. The possible enhanced charge transfer process in V 2 O 5 /rGO nanocomposite has been proposed responsible for the improved photodegradation of methylene blue (MB) dye and enhanced PEC water splitting activity. [ABSTRACT FROM AUTHOR]