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Abstract: Temperature dependent behavior of conduction noise of MgB2 superconductor has been studied. The frequency spectrum of conduction noise shows 1/fα type of behavior, with α =0.7–0.8. Temperature dependence of conduction noise is found to exhibit two peaks at ∼26K and ∼38K respectively. The peak at ∼38K is attributed to movement of vortices and due to fluctuation in resistance from change of state from superconducting to normal state. The peak in the conduction noise at ∼26K is ascribed to the movement of vortices due to enhanced thermally activated vortex hopping. The analysis of enhanced conduction noise in the low temperature region indicates the presence large density of fluctuators with activation energies around 0.048eV. [Copyright &y& Elsevier]

Abstract: ZnO and Co-doped ZnO thin films have been deposited on the sapphire substrate by ultrasonic assisted chemical vapor deposition technique. The films were annealed in vacuum at 450 °C. All the films were highly c-axis orientated and contained no impurity phase. The temperature dependence of the electrical conductivity has been measured in order to identify the dominant conduction mechanism. In the higher temperature region the dominance of thermally activated band conduction was observed whereas in the low temperature region the hopping conduction was found to dominate. The hopping conduction mechanism in the lower temperature range in the film was Mott''s Variable Range Hopping and not the Nearest Neighbor Hopping. The temperature region, where hopping conduction was dominant found to increase by Co doping in ZnO film. The localization length was found to be larger in the Co-doped ZnO film. [Copyright &y& Elsevier]

Abstract: Double layered manganite of La1.4Ca1.6Mn2O7 (DLCMO) was prepared using solid state reaction method and had a metal–insulator transition temperature (T MI) of 125K. The short range 2D-feerromagnetic ordering (TC2) starts growing when T<168K and it gets converted into 3D-ferromagnetic ordering (T C1) at 114K. Low field magnetoresistance (MR) behaviour of the DLCMO was investigated and compared with an infinite layered manganite La0.7Ca0.3MnO3 (LCMO). For DLCMO, in the temperature range between T C1 and T C2, the MR showed a gradual increase with the magnetic field. The observed MR and R–T behaviour of double layered manganite for T C1<T<T C2 has been explained in the frame work of the two phase model [ferromagnetic (FM) domains and paramagnetic (PM) regions] and percolative behaviour of transport in FM–PM mixture. [Copyright &y& Elsevier]

Abstract: Temperature dependence of conduction noise and low field magnetoresistance of layered manganite La1.4Ca1.6Mn2O7 (DLCMO) are reported and compared with the infinite layered manganite La0.7Ca0.3MnO3 (LCMO). The double layered manganite was prepared using standard solid state reaction method and had a metal–insulator transition temperature (TM–I) of 155K. The temperature dependence of susceptibility showed evolution of ferromagnetic ordering at 168K. The observed voltage noise spectral density (SV) shows 1/fα type of behaviour at all temperatures from 77K to 300K. In the ferromagnetic region (T<168K), SV/V2 shows two peaks at 164K and 114K. The observed two peaks in normalised conduction noise of DLCMO is attributed to the excess noise generated due to setting up of short range 2D-ferromagnetic ordering and long range 3D-ferromagnetic ordering at two different temperatures TC2 and TC1. In temperature range between TC1 and TC2, the magnetoresistance (MR) showed a gradual increase with the magnetic field. The observed MR has been explained in the framework of the two phase model [ferromagnetic (FM) domains and paramagnetic (PM) regions]. [Copyright &y& Elsevier]

A single artificial grain boundary in La0.67Ba0.33MnO3 (LBMO) thin film has been prepared by depositing the film on a bicrystal substrate using laser ablation technique. We investigated the magnetic field dependence of magnetoresistance and conductance–voltage characteristics of the grain boundary at 77K. A decrease of nonlinearity of current–voltage characteristics was observed upon application of magnetic field. The results are explained by assuming the presence of two different types of parallel conducting channels (metallic and highly resistive) across the grain boundary. The analysis of the results reveals that the application of magnetic field suppresses magnetic disorders at the grain boundary region and increases metallic conduction channels across the grain boundary. The temperature dependence of the conduction noise of the bicrystal grain boundary was measured at 0 and 1.5kG magnetic field and compared with a microbridge on the LBMO film having no grain boundary. The presence of the grain boundary was found to enhance noise by one order of magnitude. The noise of a bicrystal grain boundary showed a decrease in the presence of 1.5kG magnetic field for T<210K. This decrease of noise confirms that the application of a magnetic field induces more metallic channels across the grain boundary. [Copyright &y& Elsevier]

Studies of rf-SQUID effect in ternary (YRuB2, LuRuB2, LaRu3Si2) and in binary V3Si intermetallic bulk superconductors have been carried out for investigating the nature of grain boundaries in these superconductors. YRuB2 (Tc∼7.5 K), LuRuB2 (Tc∼10 K) and LaRu3Si2 (Tc∼7 K) ternary superconductors are found to show rf-SQUID voltage–flux modulations from 4.2 K to close to Tc. This indicates that the natural grain boundaries in the ternary intermetallic superconductors behave as Josephson weak links. Rf-SQUID effect is not observed in V3Si binary superconductors, which indicates that the grain boundaries in V3Si are not weak link type. STM/STS studies of the YRuB2 and V3Si grain boundaries (GB) are also reported. The interior of the GB in YRuB2 is found to be of quasi-insulating type and thus provides a weak link effect. On the contrary the interior regions of the GB of V3Si is found to be of metallic type and thus provides proximity coupling between the grains of V3Si. [Copyright &y& Elsevier]

La0.67Ca0.33MnO3 (LCMO) and Ag admixed La0.67Ca0.33MnO3 (Ag–LCMO) polycrystalline films have been prepared on SrTiO3 single crystal (100) substrates by ultrasonic spray pyrolysis technique. These films are characterized using XRD, SEM, and temperature dependence of resistivity (ρ-T) and ac susceptibility (χ-T). The films are having cubic structure with lattice parameters as 3.890 and 3.885 A˚ for LCMO and Ag–LCMO films, respectively. The peek in ρ-T curve (Tp) and the ferromagnetic transition temperature (TC) for the Ag-LCMO film is higher than that of LCMO film. The stability of both the films was tested by repeated measurements of its characteristics over a period of one week after several thermal cycling from room temperature to 77 K. In the LCMO film, the peak in the ρ-T curve (Tp) is found to shift towards lower value and conduction noise of the film increases in the subsequent measurements. In the case of Ag–LCMO the value of Tp, TC and conduction noise of the film did not change even after several measurements. Silver segregating at the grain boundaries in Ag–LCMO polycrystalline film seems to be responsible for improving the characteristics of Ag–LCMO films. [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]

Photocatalysis is a promising approach to solving environmental pollution issues using solar energy. Recently, ferroelectric materials have also attracted attention for photocatalysis due to the piezo-photo effect. Here we report the synthesis of ferroelectric calcium bismuth oxide (CBO) nanoflakes and demonstrate the influence of the piezo-photo impact on the improved photoreduction of hexavalent chromium, Cr(VI), under visible light irradiation. The structure, morphological, optical, and ferroelectric characteristics of the CBO nanoflakes were investigated using various characterization techniques. The remanent polarization obtained from the P–E loop is 0.02 μC cm−2 with a coercive field of 3.7 kV cm−1. The CBO nanoflakes showed an 80% photoreduction of Cr(VI) to Cr(III) after 120 minutes of light exposure. This photoreduction is enhanced to 94% when exposed to ultrasonic vibrations and visible light. A possible mechanism of Cr(VI) photoreduction under visible light irradiation was also proposed. The current research presents a novel and simple method for creating effective nanoflakes for environmental remediation. [ABSTRACT FROM AUTHOR]

Magnetic flux noise in MgB2 polycrystalline sample is measured using a high-TC rf-superconducting quantum interference device in the temperature range of 6–40 K. A small magnetic field (∼200 mG) was applied while cooling the sample. The flux noise exhibits 1/fα type of behavior with α∼1.0–1.3 and shows enhanced noise around 24 and 37 K. The flux noise seems to originate from thermally activated vortex hopping. The large magnetic noise at 24 K indicates the presence of larger density of pinning sites with energies ∼0.061 eV leading to enhanced magnetic fluctuations at temperatures much below TC. [ABSTRACT FROM AUTHOR]

We investigated conduction through an artificial grain-boundary junction made in La[sup 0.67]Ba[sup 0.33]MnO[sub 3] thin films, deposited on a 36.7° SrTiO[sub 3] bicrystal substrate using a laser ablation technique. The grain boundary exhibits substantial magnetoresistance at low temperatures and also shows nonlinear I - V characteristics. Analysis of temperature dependence of the dynamic conductance allows us to identify three carrier transport mechanisms across the grain boundary. These mechanisms exist in parallel, and at a given temperature one mechanism may dominate. Particularly, at higher temperatures (T > 175 K) the transport across the grain boundary involves spin-flip scattering, which we establish leads to decrease of the bicrystal grain-boundary contribution in magnetoresistance. At lower temperature (4.2-45 K), tunneling through a disordered oxide at the grain boundary dominates, whereas in the temperature range from 100 to 175 K, carrier transport is dominated by inelastic tunneling via pairs of manganese atoms. [ABSTRACT FROM AUTHOR]

Significantly enhanced photoelectrochemical (PEC) performance of the visible light active photoanodes of ferroelectric Bi 0.5 Na 0.5 TiO 3 nanostructure has been demonstrated by tuning the electrical polarization of the film. The photocurrent density of unpoled Bi 0.5 Na 0.5 TiO 3 photoanode increases from 0.48 mA cm−2 at 1 V with respect to Ag/AgCl to 1.21 mA cm−2 after negative poling, whereas it decreases to 0.18 mA cm−2 after positive poling. The incident photon-to-current conversion efficiency (IPCE) of the nanostructure photoanodes has been observed to vary from 5% to 28% just by changing the direction of electric polarization. The change in the PEC performance and enhancement in the IPCE value after switching the polarization state of Bi 0.5 Na 0.5 TiO 3 photoanodes have been attributed to the modification in the band bending at the interface of semiconductor electrode/electrolyte, leading to facilitate the increment in photogenerated charge transfer efficiency. The modulation in the band bending and variation in the charge transfer method after switching the polarization state are confirmed by Mott-Schottky (M-S) and electrochemical impedance spectroscopy (EIS) measurements. Our work provides a new visible light active ferroelectric nanostructure material for efficient visible light active photoelectrochemical performance. [Display omitted] • Hydrothermal method has been used to synthesize Bi0.5Na0.5TiO3 nanostructures. • PEC activity of Bi0.5Na0.5TiO3 photoanode improved by changing the polarization state. • Negative poled Bi0.5Na0.5TiO3 photoanode shows current density of 1.21 mAcm-2 at 1 V. • Charge transfer process on the application of electric field polarization is proposed. [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]

Herein, the combined impact of ion beam milling and postannealing treatment on the transport properties of deposited YBa2Cu3Ox (YBCO) thin film and fabricated step‐edge Josephson junction (JJ) on degraded MgO (100) substrates are investigated, and the obtained results of the YBCO thin film and fabricated step‐edge JJ on treated MgO (100) substrate are compared with the YBCO film and step‐edge junction on a fresh MgO substrate. Structural study reveals the formation of c‐axis‐oriented YBCO thin film on revived MgO substrate which is very much comparable with the YBCO film on fresh substrate. Atomic force microscopy (AFM) technique is used to confirm the step heights of the fabricated step‐edges on fresh, revived, and degraded MgO substrates. After the treatment, the surface roughness of MgO substrate has reduced from 56 to 1.06 nm which is comparable with the fresh MgO (100) substrate. The acquired values of critical temperatures for as‐deposited YBCO thin film on fresh and revived MgO substrates are 89.1 and 88.3 K, respectively, whereas these values are 85.8 and 85.7 K for the fabricated step‐edge junction microbridges on these deposited thin films. For both the fabricated step‐edge junction on the revived and fresh MgO substrate, the superconductor–normal metal–superconductor‐type JJ is confirmed. [ABSTRACT FROM AUTHOR]

The temperature and frequency dependence of conduction noise in La[sub 0.67]Ca[sub 0.33]MnO[sub 3] film are reported. The film was prepared by a screen printing technique and had a metal–insulator transition temperature (T[sub p]) and ferromagnetic transition temperature (T[sub C]) at 140 and 230 K, respectively. The magnetoresistance ratio (MRR) of the film at 1 kOe was found to be mainly due to grain boundaries. The observed voltage noise spectral density (S[sub v]) shows 1/f[sup α] type behavior for all the temperatures ranging from 77 to 300 K. S[sub v] shows an increase as the temperature is decreased below T[sub C] and reaches a peak value at T[sub p]. The increase in S[sub v] below T[sub C] is attributed to extra noise arising due to fluctuations in spin alignment in the ferromagnetic state. Application of a 1 kOe magnetic field reduces noise and the reduction in the noise is observed up to T[sub C]. A comparison of the temperature dependence of MRR and noise reduction ratio due to the magnetic field indicates that the magnetoresistance in the polycrystalline film of La[sub 0.67]Ca[sub 0.33]MnO[sub 3] is strongly influenced by the grain boundaries but the noise due to fluctuations in spin alignment is intrinsic and comes mainly from the grains. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A recreation procedure for achieving the smooth and clean surface morphology of the degraded MgO(100) substrates is presented. The surfaces of the degraded MgO(100) substrates are treated with Ar ion‐beam milling (IBM) and annealing in O2 atmosphere. After each treatment, the changes in the MgO(100) substrate surface morphology are characterized using X‐ray diffraction (XRD), a 3D optical profilometer, atomic force microscopy, and Fourier‐transform infrared (FTIR) spectroscopy and compared with a fresh MgO substrate. It is shown that before any treatment, XRD and FTIR spectra show peaks corresponding to hydroxyl and carbonate groups in the degraded samples, whereas after treatment, XRD and FTIR spectra are comparable with the fresh sample. Further, after treatment, the surface roughness Rav value for two used/degraded samples reduces from 129 and 186 nm to 3.96 and 7.91 nm, respectively, after combined Ar IBM and annealing treatment. It is shown that the surface quality of the treated MgO(100) substrate improves in comparison with as it was before any treatment and can be reused for the good quality thin‐film deposition. [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]

Triboelectric nanogenerators are devices that can transform mechanical energy into electrical energy, and regulating their performance is critical for energy harvesting applications and other applications where they act as sensors. In the present work, we have fabricated a ferroelectric PVDF-NaNbO3 nanocomposite film-based triboelectric nanogenerator and demonstrated a large tuning (64%) of the output of the triboelectric nanogenerator by adjusting its electrical polarization state. The triboelectric nanogenerator fabricated using a negatively polarized PVDF-NaNbO3 nanocomposite film has an instantaneous output power of 0.17 mW, which is significantly higher than the triboelectric nanogenerator fabricated using a positively polarized PVDF-NaNbO3 nanocomposite film, which has an output power of 0.06 mW. Kelvin probe force microscopy measurements were carried out to explore the cause of the change in the output with the change in the polarization state of the films. The work function of the PVDF-NaNbO3 film is found to change with the polarization of the film, which resulted in the change in the output. More explanation of the effect of the polarization state on the performance of the triboelectric nanogenerator has been presented using an electronic energy level diagram of the contacting materials. The current work demonstrated the advantage of using ferroelectric polymers for triboelectric nanogenerator applications, because the output performance of the triboelectric nanogenerator can be tuned as per requirement. [ABSTRACT FROM AUTHOR]

Studies radio frequency superconducting quantum interference device (SQUID) effects due to natural grain-boundary junctions in ErNi[sub 2]B[sub 2]C and DyNi[sub 2]B[sub 2]C magnetic borocarbide superconductors. Amplitude of voltage-flux SQUID modulations; Occurrence of magnetic ordering; Flux noise density of the SQUID.

We report the observation of radio frequency-superconducting quantum interference device (rf-SQUID) effect due to natural grain boundary weak links in a bulk sample of a YNi2B2C superconductor at 4.2 K, confirming that the superconducting grains are coupled at the grain boundaries through Josephson effect. Periodic oscillations in voltage-flux characteristic due to rf-SQUID effect have been clearly observed at 4.2 K when the driving rf frequency was kept slightly away from the resonance frequency of the tank circuit. Phase reversal in the voltage-flux characteristics on changing the rf frequency has been observed. Noise spectrum of the YNi2B2C bulk rf-SQUID is also reported. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines the operation of bicrystal junction high-temperature direct current-SQUID in a portable microcooler. Use of a modulation signal in SQUID operation; Importance of SQUID noise characterization in a liquid nitrogen Dewar to evaluate the performance in the microcooler; Similarities between Dewar and microcooler performance.

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]

Controlled bipolar resistive switching (BRS) has been observed in nanostructured CoFe2O4 (CFO) films using an Al (aluminum)/CoFe2O4/FTO (fluorine-doped tin oxide) device. The fabricated device shows electroforming-free uniform BRS with two clearly distinguished and stable resistance states without any application of compliance current, with a resistance ratio of the high resistance state (HRS) and the low resistance state (LRS) of >102. Small switching voltage (<1 volt) and lower current in both the resistance states confirm the fabrication of a low power consumption device. In the LRS, the conduction mechanism was found to be Ohmic in nature, while the high-resistance state (HRS/OFF state) was governed by the space charge-limited conduction mechanism, which indicates the presence of an interfacial layer with an imperfect microstructure near the top Al/CFO interface. The device shows nonvolatile behavior with good endurance properties, an acceptable resistance ratio, uniform resistive switching due to stable, less random filament formation/rupture, and a control over the resistive switching properties by choosing different stop voltages, which makes the device suitable for its application in future nonvolatile resistive random access memory. [ABSTRACT FROM AUTHOR]

Three sets of single domain CoFe2O4 nanoparticles of similar sizes (~ 10 nm) with different values of intrinsic strain have been synthesized at three different growth temperatures (120, 140 and 160 °C). The optical bandgap and saturation magnetization of these similar size magnetic nanoparticles are found to be strongly dependent upon the intrinsic strain present in the nanoparticles. The optical bandgap is found to decrease from 1.84 to 1.67 eV and the saturation magnetization decreases from 66.7 to 35.1 emu/g with increase in the intrinsic strain in the nanoparticles. The presence of intrinsic strain is found to affect the cationic redistribution at the tetrahedral and the octahedral sites of the nanoparticles. The decrease in the optical bandgap of CoFe2O4 nanoparticles with increase in the intrinsic strain is correlated to the presence of more Co2+ at the tetrahedral sites. The change in the saturation magnetization is also correlated to the increase in the population of Co2+ at the tetrahedral sites with increase in the intrinsic strain resulting in an enhanced spin canting at the octahedral sites. [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]

The effect of magnetic CoFe2O4 (CFO) nanofillers on the thermoelectric properties of the Bi2Te3–CFO nanocomposite is investigated, and their role in the enhancement of thermoelectric properties is demonstrated. In the presence of a small magnetic field (25 mT), the electrical conductivity is enhanced by 16% and, simultaneously, the Seebeck coefficient is enhanced by 23%. The presence of CFO nanoparticles in the matrix of Bi2Te3 in the nanocomposite produces an interpenetrating network of the magnetically induced orientation of the magnetic moment of CFO, which results in the substantial reduction in the interface barrier by suppressing scattering of charge carriers at the interfaces. The simultaneous enhancement in the electrical conductivity and Seebeck coefficient in the presence of the small magnetic field resulted in an ∼52% enhancement of figure of merit for the Bi2Te3–CFO (4 wt. %) nanocomposite. [ABSTRACT FROM AUTHOR]

Highlights • Visible active CZTS alerted CdS/TiO 2 tandem photoanode made-up by low cost technique. • CZTS/CdS/TiO 2 /FTO shows higher current density due to strong visible light absorption. • PEC properties of photoelectrode have significantly improved by surface modification. • Efficient separation of charge carriers after deposition of CdS and CZTS on TiO 2 /FTO. Abstract A tandem photoanode consisting of Cu 2 ZnSnS 4 (CZTS) nanoparticles layer over CdS/TiO 2 heterostructure thin film on FTO substrate has been fabricated for photoelectrochemical hydrogen generation. CdS thin film has been deposited by chemical bath deposition over the spin-coated TiO 2 thin film, which is followed by the deposition of CZTS nanoparticles layer by spray coating technique resulting in a CZTS/CdS/TiO 2 /FTO photoanode. The coating of CZTS nanoparticles layer over CdS/TiO 2 films resulted in the tandem structure of different band level positions, which enhances the optical absorption in the visible region and also leads to higher separation of the photogenerated charge carriers. A substantial enhancement (39 times) in the PEC activity has been demonstrated for the CZTS/CdS/TiO 2 /FTO photoanode as compared to TiO 2 /FTO photoanode, which is due to cascade band gap from 3.2 eV to 1.7 eV and formation of heterojunction at interfaces. The enhancement in the charge transport properties of CZTS/CdS/TiO 2 /FTO photoanode has been confirmed from the electrochemical impedance spectroscopy (EIS) measurement. The EIS results confirm that the CZTS/CdS/TiO 2 /FTO photoanode exhibited lowest charge transfer resistance (R ct = 302 Ω/cm2) as compared to CdS/TiO 2 (R ct = 615 Ω/cm2) and TiO 2 (R ct = 1700 Ω/cm2) photoanode. A mechanism depicting the enhanced the performance of photoelectrochemical (PEC) CZTS/CdS/TiO 2 /FTO photoanode has been proposed. [ABSTRACT FROM AUTHOR]

Abstract In the present work, nanostructures comprising of plasmonic silver (Ag) nanoparticles (NPs) decorated on the hydrothermally grown bismuth sulfide nanorods (Bi 2 S 3 –NR) and hierarchical nanoflowers (Bi 2 S 3 NF) have been successfully synthesized by chemical route. We have fabricated the nanostructured photoanodes and demonstrated their enhanced photoelectrochemical (PEC) performance for water splitting applications. Bismuth sulfide nanoflowers have shown appreciable increased PEC activity due to its hierarchical structure as compared to the nanorods facilitated by the faster charge transport due to the availability of more interfacial sites. Among all, Ag/Bi 2 S 3 NF photoanode has exhibited highest photocurrent density (12.34 mA/cm2 at 2 V vs. Ag/AgCl) which is ∼2 fold higher as compared to Bi 2 S 3 nanoflowers. A ∼3 fold enhancement in the incident photon-to-current conversion efficiency is achieved by Ag/Bi 2 S 3 NF photoanode as compared to Bi 2 S 3 NF photoanode. The remarkable enhancement in the photocurrent density of Bi 2 S 3 after grafting metal plasmons is attributed to its enhanced photoresponse, faster transfer of plasmon mediated hot electrons from excited state of Ag NPs to Bi 2 S 3 surface and higher separation efficiency of photogenerated charge carriers facilitated by the metal-semiconductor interface. A plausible mechanism is also proposed for the improved PEC water splitting over Ag/Bi 2 S 3 NF photoanode. Graphical abstract Plasmonic silver (Ag) NPs have been successfully grafted on the hydrothermally grown bismuth sulfide nanorods (Bi 2 S 3 –NR) and hierarchical nanoflowers (Bi 2 S 3 NF) via chemical method. The Ag NPs coupled Bi 2 S 3 photoanode (Ag/Bi 2 S 3 NF) has demonstrated ∼2 and ∼3 fold enhancement in the photocurrent density and incident photon-to-current conversion efficiency (IPCE), respectively as compared to Bi 2 S 3 NF photoanode. The observed enhancement in the PEC activity for Ag/Bi 2 S 3 NF photoanode is attributed to the faster transport of plasmon mediated hot electrons from excited state of Ag NPs to the conduction band of Bi 2 S 3 nanoflowers and the slower recombination rate of photogenerated charge carriers facilitated by the metal-semiconductor interface. Image 1 Highlights • Bi 2 S 3 has been synthesized in the form of nanorods and hierarchical nanoflowers by hydrothermal method. • Plasmonic Ag NPs have been grafted on the Bi 2 S 3 nanostructures by chemical route. • A ∼2 and ∼3 fold enhancement in the photocurrent density and IPCE is achieved by Ag/Bi 2 S 3 NF as compared to Bi 2 S 3 photoanode. • The improvement is due to the enhanced photoresponse and surface plasmonic effect. [ABSTRACT FROM AUTHOR]

Discusses the importance of the role of isoenergetic charge transfer and inelastic charge transfer. Components of a photoelectric solar cell; Rate of photogeneration of charge carriers for monochromatic radiation; Process for the charge transfer via surface states.

Single-phase Cu 2 ZnSnS 4 (CZTS) thin films have been spray deposited on glass substrate, using uniform size oleic acid coated CZTS nanoparticles and the effect of heating temperature (75 °C to 300 °C) on the structural and optical properties have been investigated. X-ray diffraction results confirmed the formation of the single phase CZTS with a preferred orientation in (112) plane. The crystallite sizes of these films are ~7.0 ± 0.5 nm but the intrinsic strain present in the nanostructured films decreases from 9.1 × 10 −3 to 1.3 × 10 −3 with the increase of the heating temperature from room temperature to 300 °C. Optical band gap of the as deposited CZTS films is ~1.72 eV and it decreases to 1.45 eV for the CZTS films heated at 300 °C. The observed red shift in the band gap of CZTS films with the heating temperature has been attributed to a reduction in the intrinsic strain present in the film with the increase in the heating temperature. [ABSTRACT FROM AUTHOR]

Superhydrophobic transparent thin films using Mn doped zinc oxide (Mn/ZnO) and polystyrene (PS) composites have been synthesized successfully by chemical solution method. The nanocomposites thin films were fabricated by using Mn/ZnO and PS mixture in toluene, followed by film casting on glass substrate. For a comparison ZnO nanoparticles thin film was also prepared with PS. Mn/ZnO nanostructures have been synthesized by hydrothermal method using hexamethylenetetramine (HMTA) as a capping agent. The XRD analysis shown that the development of hexagonal wurtzite structure of Mn/ZnO with preferred (101) orientation. SEM analysis shown that Mn/ZnO nanorods have been uniformly dispersed in the PS matrix. Water contact angle (WCA) was found as 107° and 151° for the ZnO@PS and Mn doped ZnO@PS thin film, respectively. The transparency of the Mn doped ZnO@PS films are also large (∼90%) as compared to ZnO@PS film (∼80%) which is attributed to enhanced energy band gap of ZnO after Mn doping. The larger contact angle (WCA ∼151°) in the Mn/ZnO@PS thin film has been recognized to the rough surface of PS thin film due to the presence of Mn/ZnO nanorods. The present process is very simple and embrace ability for extensive applications for making super hydrophobic transparent surfaces. [ABSTRACT FROM AUTHOR]

In the present work, photoanodes comprising of NaNbO 3 nanorods and Ag nanoparticles decorated NaNbO 3 nanorods have been fabricated by using hydrothermal and chemical solution method respectively. Photoelectrochemical water splitting performance of the fabricated photoanodes have been measured and it is found that Ag decorated NaNbO 3 nanorods exhibit ∼4 fold enhancement in photocurrent as compared to bare NaNbO 3 nanorods. The enhancement in the photoelectrochemical water splitting activity of Ag decorated NaNbO 3 nanorods is attributed to efficient charge carrier separation and visible light sensitization due to Ag nanoparticles on NaNbO 3 nanorods. [ABSTRACT FROM AUTHOR]

The resistive switching behavior and nonvolatile memory effects have been investigated in poly (3-hexylthiophene) (P3HT) and carbon nanotubes (CNT) composite thin films. The memory devices with FTO/P3HT-CNT/Al structure were fabricated by varying the CNT content in the composite. The memory device with 4% CNT in P3HT exhibited a typical bipolar resistive switching with set voltage of ∼1.8 V and a high ON/OFF ratio of >10 2 . The nonvolatile behavior of the device has been studied by the retention test and showed good retention properties for >10 3  s. The resistance-temperature dependence of different resistance states has also been investigated. Ohmic conduction was found to be a dominant conduction mechanism in low bias region, whereas for the high voltage regime space charge limited conduction was found to be the ruling current conduction mechanism. Bipolar resistive switching characteristic of the nanocomposite film is explained on the basis of rupture and formation of carbon-rich filaments. [ABSTRACT FROM AUTHOR]

Abstract: A model is used to simulate batch copolymerization of caprolactam with hexamethylene diamine (HMD) and adipic acid (ADA) to produce nylon 6/6,6. Four different recipes are considered: a recipe containing caprolactam and an aqueous solution of HMD and ADA, a recipe containing caprolactam and dry HMD/ADA salt, and two recipes with a portion of the caprolactam replaced by nylon 6 cyclic dimer (CD). Consuming CD would be advantageous because CD is an undesirable side product from nylon 6 production. Simulation results lead to three important findings: (i) operation using dry salt rather than aqueous salt solution leads to higher degree of polymerization, (ii) substantial quantities of CD can be consumed to produce nylon 6/6,6 copolymer, and (iii) including water in the recipe is beneficial for achieving improved consumption of CD. The results of this study will be helpful in designing experiments aimed at improving industrial nylon 6/6,6 copolymerization processes. [ABSTRACT FROM AUTHOR]

Thermoelectric studies of Cu 2 ZnSnS 4 (CZTS) thin films deposited at different substrate temperatures by ultrasonic assisted chemical vapor deposition technique have been carried out. In order to identify the effect of compactness, crystallinity and formation of secondary phases (Cu 2 − x S and SnS 2 ) on the thermoelectric properties of CZTS thin films, the films were deposited at different substrate temperatures. Detailed analysis of temperature dependent electrical resistivity (ρ) and Seebeck coefficient (S) have been carried out. Significant enhancement in the value of thermoelectric power factor (S 2 /ρ) is achieved in CZTS film deposited at 375 °C substrate temperature, which is correlated to the compactness of thin films, improved crystallinity and presence of metallic secondary phase. Furthermore, Surface topography and surface potential studies also carried out to study the roughness and distribution of interfaces between CZTS and secondary phases (Cu 2 − x S and SnS 2 ) in CZTS thin films. [ABSTRACT FROM AUTHOR]

Bi 2 Te 3 –MWCNT nanocomposite has been synthesized by hydrothermal technique and demonstrate the role of MWCNT for thermoelectric properties. Herein, MWCNT has been used as conducting filler, which leads to the enhancement in the electrical conductivity in the case of nanocomposite. Bi 2 Te 3 –MWCNT nanocomposite shows ~22% decrease in the thermal conductivity as compared to Bi 2 Te 3 nanostructures, which is attributed to the enhanced phonon scattering at the interfaces of Bi 2 Te 3 –MWCNT nanocomposite. Due to the increase in the electrical conductivity and decrease in the thermal conductivity, the overall enhancement in the figure of merit is ~45% in Bi 2 Te 3 –MWCNT nanocomposite as compared to Bi 2 Te 3 nanostructures. [ABSTRACT FROM AUTHOR]

A noble metal-free photocatalyst, consisting of graphitic carbon nitride (g-C 3 N 4 ), TiO 2 and carbon nanotubes (CNT) was synthesized by a facile hydrothermal method and its application for the photocatalytic decolouration of methylene blue (MB) dye under visible light irradiation has been demonstrated. The microstructure, morphology, structural and optical properties of the synthesized nanocomposites was systematically studied using TEM, SEM, XRD, RAMAN, FTIR and UV–Vis DRS techniques. The g-C 3 N 4 /TiO 2 /CNT ternary nanocomposite exhibits five times higher photocatalytic activity compared to bare g-C 3 N 4 under visible light irradiation. Enhanced photocatalytic performance of the ternary nanocomposite has been attributed to the synergistic effects of three components: Multistep charge transfer between heterojunction formation at g-C 3 N 4 /TiO 2 interface and CNT, enhanced visible-light absorption and effective charge separation. A possible reaction mechanism has been proposed and scavenger experiment has been carried out to find the role of active radical species responsible for the dye decolouration. Additionally, the g-C 3 N 4 /TiO 2 /CNT photocatalyst retained excellent stability even after several cycles. This study offers a promising way of developing a highly efficient, noble metal-free, stable and visible-light-driven photocatalyst to promote the utilization of solar energy for environmental purification. [ABSTRACT FROM AUTHOR]

A model is developed for hydrolytic copolymerization of caprolactam with hexamethylene diamine (HMD) and adipic acid (ADA) in a batch reactor to produce nylon 6/6,6 copolymer. The reaction mechanism includes hydrolysis of caprolactam and cyclic dimer, polycondensation, polyaddition, transamidation, and ring formation via end biting and back biting. The catalyzing effect of carboxyl groups is accounted for using kinetic parameters from the literature. Model predictions are compared with low-temperature literature data before simulating reactor conditions of industrial interest. The model predicts a higher degree of polymerization (DP) for nylon 6/6,6 copolymer compared to nylon 6 and 6,6 homopolymers produced using the same reactor conditions. Dynamic changes in concentrations of water, caprolactam, HMD, ADA, and end groups are tracked and used to explain the positive influence of comonomers on reaction rates and DP. Insights gained from this model will form a useful basis to build future models of continuous industrial reactors. [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]

[Display omitted] • Self-biased TE-coupled PEC hybrid system for hydrogen generation is demonstrated. • The Ag/NaNbO 3 photoanode onset potential is cathodic shifted in a hybrid system. • A ∼17 times enhancement in the H 2 production of TE-coupled PEC system is achieved. Nanostructure semiconductor photoactive materials are often used as working photoelectrodes to absorb solar light in conventional photoelectrochemical (PEC) cells for water splitting to demonstrate enhanced PEC performance. However, an external bias is required to start PEC water splitting reactions for the generation of hydrogen. Here, we demonstrate a novel way of designing a self-biased hybrid system that combines a darkened thermoelectric device (TE) and a photoelectrochemical cell with a visible light-active n-type Ag/NaNbO 3 photoanode to produce hydrogen via water splitting by utilizing the entire solar spectrum. This method can combine utilization of a visible light photon energy from the Ag/NaNbO 3 photoanode with thermal energy from the darkened TE device to overcome the overpotential requirements. Upon light illumination, the photoactive behaviour of the Ag/NaNbO 3 photoanode and the voltage generated from the darkened TE device in our hybrid system modifies the band positions of an Ag/NaNbO 3 photoanode and spontaneously provide the external overpotential requirement for the PEC process and enhances the H 2 production. Compared to the stand-alone PEC device, the TE-coupled PEC hybrid system exhibited ∼17 times enhancement in the photocurrent density and H 2 production at zero bias. The electrochemical impedance spectroscopy analysis also shows that the charge transfer process gets significantly enhanced in the hybrid PEC system compared to the PEC cell alone. This finding indicates the synergistic coupling between TE and PEC cells, where a single light energy source can increase H 2 production in the hybrid systems without needing an external bias. [ABSTRACT FROM AUTHOR]

In the present work, the effect of the addition of potassium niobate (KNbO3) nanoparticles (NPs) on the pinning properties of YBCO compound is investigated. The synthesis of YBCO:xKNbO3 (x = 0–1 wt%) nanocomposites were carried out using a two-step process, firstly KNbO3 NPs were synthesized via hydrothermal process, and later on, the nanocomposites were synthesized via solid-state reaction method containing various concentrations of NPs from 0 to 1 wt%. The effect of NPs of KNbO3 in YBCO is studied using structural, morphological, transport, and magnetic measurements. From XRD spectra, the crystal structure of YBCO was found to be orthorhombic, which remained invariant even in the nanocomposites. Magnetic properties of YBCO and its nanocomposites over the range of − 6 T to + 6 T were characterized using magnetic property measurement system (MPMS). The Bean model is applied to calculate the critical current density (JC), which has improved in YBCO:KNbO3 nanocomposites as compared to YBCO. The maximum enhancement of ~ 4.4 times in JC and pinning properties was found for YBCO:0.5wt%KNbO3 nanocomposites due to the creation of defects in YBCO matrix. Additionally, it is observed that for nanocomposites compared to YBCO, the rate of JC decay decreases with an increase of externally applied field, which indicates an enhancement in pinning properties of nanocomposites. [ABSTRACT FROM AUTHOR]

Picric acid is very dangerous environmental pollutant generated from leather, chemical and dye industries due to its high toxicity. Therefore, efforts have been made to develop techniques for the efficient detection of picric acid. A new and novel biomolecule inspired polyindole/CdS (PIN/CdS) nanocomposite has been synthesized by an in situ chemical polymerization method for the detection of picric acid in organic medium. The PIN/CdS nanocomposite was characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Energy dispersive X-ray (EDAX), ultraviolet-visible (UV-Vis) and fluorescence spectroscopy, in order to evaluate its optical properties, particles size distribution and morphology. The synthesized nanocomposite shows remarkably high sensitivity and selectivity towards picric acid, compared to the other organic compounds like aniline, benzoic acid, nitrobenzene, benzamide and nitromethane. The Stern–Volmer constant (KSV) value was found to be 30 × 103 M−1 for the detection of picric acid, confirming very high sensitivity of the PIN/CdS nanocomposite for picric acid. [ABSTRACT FROM AUTHOR]

A Semiconductor to metal transition has been observed in hydrothermally synthesized CoFe 2 O 4 (CFO) nanoparticles. Temperature dependent Seebeck coefficient was measured in order to confirm the type of majority charge carriers and conductivity vs. temperature measurement was performed to get the activation energy. The CFO nanoparticles shows p-type semiconducting behaviour at lower temperature as confirmed by the sign of Seebeck coefficient and at elevated temperatures a sign inversion in Seebeck voltage was observed. The p-type and n-type semiconducting behaviour have been attributed to hopping of holes and electrons between Co 3+ –Co 2+ and Fe 2+ –Fe 3+ respectively dominating at different temperatures. [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]

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]