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Nanourchin VO2 nanostructures have been effectively synthesized by hydrothermal method. The synthesized hierarchical nanostructure has been characterized by various characterization techniques and electrochemical behaviour has been studied. X-ray diffraction analysis revealed the monoclinic phase and morphological analysis (FESEM) of VO2 showed nanourchin-like structure with arrangement of various nanorods in radial fashion. Over these nanorods, formation of secondary growth of asterisk-shape structure was observed. The width and length of nanorods were ~ 50 and ~ 75 nm, respectively. For the electrochemical measurements, 2032 type coin cells were fabricated using VO2 as electrode material. The electrochemical study of VO2 exhibited the pseudocapacitive behaviour with specific capacitance of 44 F g−1 in organic electrolyte with symmetric capacitor of two electrode system. The maximum energy density and power density were 44 and 8635 Wh kg−1, respectively. Cycling performance exhibited symmetric charge–discharge curves, and also specific capacitance was maintained up to 82% of initial value. [ABSTRACT FROM AUTHOR]

Lithium ion batteries (LIB) are the most promising energy storage systems for portable electronics and future electric or hybrid-electric vehicles. However making them safer, cost effective and environment friendly is the key challenge. In this regard, replacing petro-derived materials by introducing renewable biomass derived cellulose derivatives and lignin based materials into the battery system is a promising approach for the development of green materials for LIB. These biomaterials introduce sustainability as well as improved safety in the final disposal of LIB batteries. In this review we introduce LIB materials technology in brief and recent developments in electrodes and binders based on cellulose and their derivatives and lignin for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: Highly transparent and water soluble nanocomposite of conducting polyaniline wrapped-multiwalled carbon nanotubes (PANI-MWCNTs) was synthesized by in situ chemical polymerization method using sulphonic acid as a dopant. MWCNTs were functionalized prior to their use and then polymerized using ammonium per sulphate as an oxidizing agent. The nanocomposite was subjected for physico-chemical characterization using spectroscopic (UV–vis and FT-IR), FE-SEM and HR-TEM analysis. The UV–vis spectrum of the salt phase (dark green) of the PANI-MWCNTs nanocomposite shows a free carrier tail with increasing absorption at higher wavelength, which confirms the presence of conducting emeraldine salt phase of the polyaniline and is further supported by FT-IR analysis. However, the base form (deep blue) of the nanocomposite shows a sharp peak at 600nm representing an insulating emeraldine base phase of the polymer. The FE-SEM images show the uniform wrapping/coating of the polyaniline over the functionalized MWCNTs and this is further supported by HR-TEM analysis. The synthesized nanocomposite was then successfully used for the determination of pH of the solution (pH 1–12) and found to be a potential candidate for optical pH sensing. [Copyright &y& Elsevier]

In this paper, we are reporting a novel spinel metal oxide photocatalyst, ZnBiGaO4 for the photocatalytic decomposition of hydrogen sulfide (H2S) to generate hydrogen. ZnBiGaO4 was prepared by two different methods. One is usual solid-state route and another is hydrothermal route, and this is the first time we are reporting ZnBiGaO4 synthesized by this route. The newly prepared ZnBiGaO4 was characterized for its crystal structure and microstructure by using XRD and Field Emission Scanning Electron Microscopy (FESEM), respectively. XRD analysis revealed that the structure of ZnBiGaO4 is cubic spinel structure. The photocatalyst was also characterized by using UV–Visible diffuse reflectance spectroscopy to determine its band gap and was estimated to be 2.8 eV. Our prima facie observations revealed that the formation of single-phase cubic spinel ZnBiGaO4 with significant photocatalytic activity under visible-light irradiations for solar hydrogen generation from H2S. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A series of new substituted 2‐amino‐3‐cyano‐4H‐chromene derivatives have been synthesised by one pot multicomponent reaction of substituted benzaldehyde, malononitrile and 4‐chloro resorcinol. All the synthesised compounds have been characterised using FT‐IR, 1H NMR, 13C NMR and HR‐MS spectra and screened for bioactivities such as swarming behaviour, biofilm formation, biofilm disruption, urease production in Proteus mirabilis. Whereas swarming inhibition was shown by all synthesized chromene derivatives, biofilm inhibition was shown only by nitrophenyl and fluorophenyl substituted chromene derivatives. Interestingly, urease activity was shown by meta substituted nitrophenyl and fluorophenyl derivatives. Quantitative polymerase chain (qPCR) reaction used to investigate the molecular mechanism of most active chromene derivatives showed prominent down regulations of urease enzyme genes. Molecular docking study against urease supported the observed bioactive effect and provide valuable insights into the binding modes and affinities of these new chromene derivatives. The per‐residue interaction analysis proposed the involvement of non‐bonded (steric and electrostatic) and bonded (hydrogen bonding and pi‐pi stacking) interactions with the active site. [ABSTRACT FROM AUTHOR]

This article reports the studies on Li-ion full-cell fabrication using Li4Ti5O12 (LTO) as anode and LiCoO2 (LCO) as cathode materials with emphasis on scaling from coin cell (2032 type) to rectangular pouch-type cells (45 × 58 mm). The electrode materials were synthesized in-house and characterized for their phase purity and morphology using XRD and FE-SEM techniques. Their electrochemical performance is evaluated against Li/Li+ using cyclic voltametry, electrochemical impedence spectrosopy and galvanostatic charge–discharge. The optimized materials were further used for fabrication of full cells in 2032 type initially and later in pouch cell geometry with different negative (N) to positive (P) electrode ratio (N/P ratio) and tested its effect on the cell performance. It is found that cells employing an N/P ≥ 1.0 can give steady and good performance in terms of discharge capacity. In case of 2032 type full cell, for N/P ≥ 1.0, the maximum achieved specific capacity is 118 mAh g−1 while 110 mAh g−1 for pouch cell in the same N/P ratio. The impedance spectroscopy has been employed to support the performance of the cells. This finding can be used as a guideline for preparing full cells for other electrode combinations as well as higher capacity cells. This will also help in designing efficient battery management system. [ABSTRACT FROM AUTHOR]

Transition metal oxides are the most promising candidates in low-cost and eco-friendly energy storage/conversion applications. Herein, bare Mn2O3 and a Mn2O3/reduced graphene oxide (rGO) composite have been synthesized by a facile chemical co-precipitation and subsequent annealing procedure. The synthesized Mn2O3/rGO composite exhibits a porous microcube structure formed with several interconnected particles. The porous Mn2O3/rGO composite, with high surface area and increased conductivity, facilited the charge transfer to enhance the overall electrochemical performance when applied as an anode material in Li-ion batteries. The porous Mn2O3/rGO composite exhibits a highly reversible lithium storage capacity of 1015 mA h g−1 at a rate of 0.5 C (230 mA g−1) during 130 cycles with excellent cycling stability and rate capability. The superior electrochemical performance results mainly due to the combined effect of rGO and Mn2O3, which offers high conductivity, faster Li+ ion transfer, and enhanced structural stability. The material synthesis strategy presented in this study is simple, cost-effective and scalable, which can open new avenues for large-scale applications of composites of graphene and other transition metal oxides. [ABSTRACT FROM AUTHOR]

Tin oxides are the most promising anode materials for sodium-ion batteries (SIBs) owing to their abundance and their multi-electron reactions, which ultimately provide a high theoretical capacity. However, the huge volume expansion and consequent stability issues of tin and tin oxide anodes have relentlessly hindered their application in Na-ion batteries. To overcome these drawbacks, we present a facile strategy to prepare a non-metal-doped Sn3O4 anode by facile hydrothermal route and the investigation of its sodium-ion storage performance. B-F@Sn3O4 exhibits a triclinic structure with nanoflake morphology, length of 40–100 nm, and thickness of 10–15 nm. When applied as the anode material for SIBs, the resultant material exhibits excellent sodium-ion storage abilities in terms of cycling stability and high rate capability. In SIBs, the Sn3O4 anode capacity was observed to be 732.8 mA h g−1 at a current density of 50 mA g−1, and good cycling performance at 200 mA g−1 with a capacity retention of 77.5% after 120 cycles. Furthermore, the diffusion coefficients of the sodium ions calculated based on EIS measurements were observed to be in the range of 10−13 to 10−11 cm2 s−1, which reveals the admirable diffusion mobility of Na atoms in the Sn3O4 nanoflakes. Moreover, a coin-type sodium-ion full cell consisting of the B-F@Sn3O4 anode and a Na3V2(PO4)3 cathode exhibited a capacity of 81.2 mA h g−1 at C/20. This study demonstrates that the Sn3O4 is a promising anode material for SIBs. Thus, the B-F-doped Sn3O4 material assembled by interconnected nanoflakes is capable of providing fast carrier transmission dynamics and outstanding structural integrity, suggesting the feasibility of the current framework for sodium-ion storage. [ABSTRACT FROM AUTHOR]

Developing efficient, low-cost, and environment-friendly electrocatalysts for hydrogen generation is critical for lowering energy usage in electrochemical water splitting. Moreover, for commercialization, fabricating cost-efficient, earth-abundant electrocatalysts with superior characteristics is of urgent need. Towards this endeavor, we report the synthesis of PANI--MnMoO4 nanocomposites using a hydrothermal approach and an in situ polymerization method with various concentrations of MnMoO4. The fabricated nanocomposite electrocatalyst exhibits bifunctional electrocatalytic activity towards the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) at a lower overpotential of 410 mV at 30 mA cm-2 and 155 mV at 10 mA cm-2, respectively in an alkaline electrolyte. Furthermore, while showing overall water splitting (OWS) performance, the optimized PM-10 (PANI--MnMoO4) electrode reveals the most outstanding OWS performance with a lower cell voltage of 1.65 V (vs. RHE) at a current density of 50 mA cm-2 with an excellent long-term cell resilience of 24 h. [ABSTRACT FROM AUTHOR]

In the present work, we have demonstrated the synthesis of Molybdenum Carbide‐reduced graphene oxide (Mo2C‐rGO) heterostructure. Uniquely, the in‐situ formation of rGO using D‐glucose in the heterostructure and its battery performance has been discussed. The High Resolution Transmission Electron Microscopy (HR‐TEM) study clearly shows the growth of Mo2C nanoparticles along with rGO confers a unique integrated layered heterostructure. X‐ray diffraction (XRD) and Raman study exhibits the formation of graphene oxide (GO) followed by multi‐layers of rGO along with hexagonal Mo2C. The electrochemical study of Mo2C‐rGO heterostructure demonstrates stable cycling performance and excellent rate capabilities. The heterostructure showed the initial capacity (1st discharge) around 632.23 mAh/g and specific capacity i. e., 537.91 mAh/g @ 0.5 A/g with 99–100 % columbic efficiency. The reversible capacities of 521.56 mAh/g, and 400.76 mAh/g were observed at current densities of 1 A/g and 2 A/g for 300 cycles, respectively, which justifies the stability of heterostructure. The cycled cell was investigated by using Electrochemical Imepedance Spectroscopy (EIS), ex‐situ XRD, and Field Emmision Scanning Electron microscopy (FESEM), which shows the negligible change in the ionic conductivity, structure, and morphology after 300 cycles. It shows the excellent stability of Mo2C‐rGO heterostructure. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile and scalable solid state‐inspired protocol has primarily been devised aiming at the large-scale production of nitrogen-doped Li 4 Ti 5 O 12. • Synthesis approach provides densely packed highly crystalline particles that exhibit lower Warburg coefficient and higher Li ion diffusion. • Apt nitrogen-doped LTO as a working electrode in Li-ion, displays enhancement in Li-storage capacity by 30% and ultra-long cycling stability. • Further, a full cell with LiCoO 2 demonstrated encouraging results for NLT2, achieving capacities of more than 155 mAh/g. Lithium titanate, Li 4 Ti 5 O 12 (LTO) is being explored as an anode in Li-ion batteries owing to its minimal structural change during lithiation/delithiation and excellent capacity retention at higher current rates. However, the lack of stable cyclability at higher applied currents owing to low electronic conductivity, restricts its widespread applications. Solid state anionic doping represents a convenient strategy to improve the intrinsic electronic conductivity of the LTO material. Hence, a facile and scalable solid state‐inspired protocol has primarily been devised aimingthe large-scale production of nitrogen-doped LTO. The structural analysis demonstrates the diffusion of nitrogen into the lattice without damaging the intrinsic microstructure of LTO. The 2% nitrogen-doped LTO as a working electrode in Li-ion half-cell, displays enhancement in Li-storage capacity by 30%. Moreover, it exhibits excellent rate performance (131 mAhg−1 @ 5C) and ultra-long cycling stability upto 1000 cycles retaining 82 % capacity. Further, full cell study of N@LTO with LiCoO 2 exhibits specific capacities of more than 155 mAh/g at a 0.05C rate. Overall, the enhancement in performance attributes to N doping which is likely to improve not only the electrical conductivity but also the ion transport capabilities. Hence the N@LTO will have potential in high power Li-ion batteries. [ABSTRACT FROM AUTHOR]

The ABO3 type perovskite oxide‐based ceramic membranes are one of the most important classes of materials for high‐temperature solid oxide fuel cell applications. The acceptor‐doped calcium titanate (CaTiO3) perovskite has attracted considerable attention as an oxide ion‐conducting membrane due to its potentially high ionic conductivity and excellent stability. Nonetheless, the ionic conductivity of the material must still be improved. Following the strategy of the substitution of dopants on the B‐site, the current work is focused on exploring the effect of Al and Ni additions on electrical properties, by studying the nominal compositions CaTi0.7Al0.3–xNixO3−δ (x = 0, 0.1, 0.2 and 0.3). The materials were synthesized by the sol–gel method and studied as a function of phase composition, microstructure, and electrical properties. The results demonstrate an increase of both total and specific grain boundary conductivity with increasing Ni content, while predominant p‐type behavior is shown under oxygen‐rich atmosphere. [ABSTRACT FROM AUTHOR]

Abstract: Herein, for the first time, CuAlGaO4 is demonstrated as an efficient visible-light-active (band-gap of 1.87eV, λ ≥420nm) photocatalyst for solar H2 production. The CuAlGaO4 prepared by solid-state method is capable of producing 3214μmol of H2 per hour from H2S photodecomposition under visible-light irradiation with quantum yield of 10.8% at 550nm. Loading with 1wt.% NiO enhances the rate of H2 generation of the photocatalyst to 3616μmolh−1 with quantum yield of 12.7% at 550nm. The CuAlGaO4 exhibits a spinel structure with particle size varying from a few nanometers to a few micrometers. The regenerated catalysts validate the stability and the reusability. [Copyright &y& Elsevier]

Summary: Hybrid metal oxide heterostructures have been considered as ideal and potential anode materials for lithium ion batteries (LIBs) due to their better electrochemical performances, such as reversible capacity, structural stability and electronic conductivity. Herein, we have demonstrated synthesis of NiCo2O4/BiVO4 heterostructures by simple hydrothermal strategy to construct hybrid xNiCo2O4/(1–x)BiVO4 heterostructures with four selected compositions, that is, x = 10%, 20%, 30% and 40%. XRD shows the phases of NiCo2O4 and BiVO4 and FE‐SEM data revealed strong interface coupling between NiCo2O4 nanowires and BiVO4 dendrites. Upon testing for electrochemical properties, the optimized composition of 30%NiCo2O4‐70% BiVO4 showed higher reversible capacity of 408.6 mAh/g at a constant current rate of 0.5 A/g after 1000 cycles with columbic efficiency around 99% suggesting potential electrode material for high‐performance LIBs. The higher capacity is mainly attributed to the large surface area which can provide more channels and locations for fast Li ion intercalation/de‐intercalation into electrode materials. Additionally, improved Li ion storage capacity with superior rate capability of BN‐30 electrode could be attributed to its lower charge‐transfer resistance. The dendritic and nanowire heterostructure novel system with good stable capacity for LIBs is hitherto unattempted. [ABSTRACT FROM AUTHOR]

Degradation of spent wash waste is a very essential but challenging task in the indian sugarcane distillery industry because of its awfully acidic pH, and intense brown colour with a strong unpleasant odour. Prior to discharge in the environment, its degradation using an efficient and cost effective method is important. A photo-catalytic degradation route could be a simple, cost effective alternative to conventional degradation processes. Cu-doped TiO2 was synthesised using a facile sol gel assisted hydrothermal method at various temperatures such as 120, 150 and 180 °C. Cu–TiO2 with doping concentrations of 0.5 to 5% were synthesized using the hydrothermal method. The physico-chemical properties of the synthesised Cu–TiO2 were investigated by using various characterization techniques. UV-visible analysis shows a red shift in the absorption wavelength in the case of Cu–TiO2 as compared with bare TiO2. Structural and morphological analysis confirms the formation of anatase TiO2 with a nano-orthorhomb like morphology. The photocatalytic performance of the TiO2 and Cu doped TiO2 samples was evaluated for degradation of spent wash colour under natural solar light irradiation. Among all the Cu–TiO2 samples, 1% Cu–TiO2 synthesized at 150 °C exhibited the maximum degradation efficiency with almost 59% degradation of the spent wash in 5 h. The molecular weight of the colour compounds after degradation was monitored using gel permeation chromatography (GPC). The GPC fractions show low, medium, and high molecular weight coloured compounds with a strong hypsochromic shift. Identification of the compounds in each of the GPC fractions was studied using liquid chromatography mass spectrometry quadrupole time of flight (LC-MS Q-TOF). [ABSTRACT FROM AUTHOR]

Summary: Hybrid metal oxide heterostructures have been considered as ideal and potential anode materials for lithium ion batteries (LIBs) due to their better electrochemical performances, such as reversible capacity, structural stability and electronic conductivity. Herein, we have demonstrated synthesis of NiCo2O4/BiVO4 heterostructures by simple hydrothermal strategy to construct hybrid xNiCo2O4/(1–x)BiVO4 heterostructures with four selected compositions, that is, x = 10%, 20%, 30% and 40%. XRD shows the phases of NiCo2O4 and BiVO4 and FE‐SEM data revealed strong interface coupling between NiCo2O4 nanowires and BiVO4 dendrites. Upon testing for electrochemical properties, the optimized composition of 30%NiCo2O4‐70% BiVO4 showed higher reversible capacity of 408.6 mAh/g at a constant current rate of 0.5 A/g after 1000 cycles with columbic efficiency around 99% suggesting potential electrode material for high‐performance LIBs. The higher capacity is mainly attributed to the large surface area which can provide more channels and locations for fast Li ion intercalation/de‐intercalation into electrode materials. Additionally, improved Li ion storage capacity with superior rate capability of BN‐30 electrode could be attributed to its lower charge‐transfer resistance. The dendritic and nanowire heterostructure novel system with good stable capacity for LIBs is hitherto unattempted. [ABSTRACT FROM AUTHOR]

In the present study, we have demonstrated a unique approach for the synthesis of nanostructured ternary metal sulphides, XIn2S4 (X = Cd, Zn), using a simple, template free and low temperature solid phase reaction. A stoichiometric amount of precursors including CdO/ZnO, In2O3 and thiourea were mixed homogeneously and heated at 150 °C for different time intervals to produce nanostructured XIn2S4. Various molar ratios of the precursors were tried and among the different ratios, the molar ratio of 1 : 1 : 8 was found to be optimum for the growth of phase pure nano crystalline XIn2S4. X-ray analysis confirms the formation of cubic spinel Cadmium Indium Sulfide (CdIn2S4) and hexagonal Zinc Indium Sulfide (ZnIn2S4). HRTEM analysis confirms the formation of nanostructures of XIn2S4 with spherical and rod like mixed morphology. The band gap of the as synthesized materials is within the visible region i.e. 2.25 and 2.6 eV for CdIn2S4 and ZnIn2S4, respectively. Therefore, the activity of both the photocatalyts was tested for hydrogen generation by H2S and H2O splitting under natural solar light. The ZnIn2S4 photocatalyst was found to be more active for both H2S and H2O splitting reactions with H2 evolution rates of 6994 μmol h−1 g−1 and 243 μmol g−1, respectively, whereas for CdIn2S4 the rates were found to be 6128 μmol h−1 g−1 and 128.4 μmol g−1, respectively. The H2 evolution rate by H2S splitting was found to be much higher than various previously reported nanostructured photocatalysts. The simple, environmentally friendly and cost effective method reported herein can be applied for the large scale synthesis of XIn2S4 nanoparticles, which is the novelty of the present work. [ABSTRACT FROM AUTHOR]

SnO2@C nanocomposites were synthesized using a citrate gel method in one step. Carbon has been used to increase the conductivity of pristine SnO2. The SnO2@C nanocomposites show nanoparticles sized in the range of 30–50 nm. A structural study by XRD shows the tetragonal rutile structure of SnO2. Furthermore, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirm the existence of SnO2 along with carbon. The electrochemical performance was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge measurements. The nanocomposite has been used as an anode material for lithium-ion batteries. Pristine SnO2 exhibited a discharge capacity of 1854 mA h g−1 and a corresponding charge capacity of 1038 mA h g−1 for the first cycle. The SnO2@C nanocomposite showed a discharge capacity of 2574 mA h g−1 and charge capacity of 1481 mA h g−1 for the first cycle. These results clearly show the effect of carbon incorporation in SnO2. Furthermore, the nanocomposite shows a discharge capacity as high as 725 mA h g−1 after 200 cycles at a current density of 50 mA g−1. Thus, the obtained capacity for the nanocomposites is much higher as compared to that for pristine SnO2, i.e., 119 mA h g−1 at 50 mA g−1 after 200 cycles. The higher capacity in the nanocomposites is due to the fast transport of electrons and easy transport of lithium ions due to the carbon in the nanocomposites. The SnO2@C nanocomposite anode exhibits superior cycling stability and rate capability due to its stable electrode structure. [ABSTRACT FROM AUTHOR]

We report optical studies with magneto-optic properties of Bi2S3 quantum dot/wires-glass nanocomposite. The size of the Q-dot was observed to be in the range 3-15 nm along with 11 nm Q-wires. Optical study clearly demonstrated the size quantization effect with drastic band gap variation with size. Faraday rotation tests on the glass nanocomposites show variation in Verdet constant with Q-dot size. Bi2S3 Q-dot/wires glass nanocomposite demonstrated 190 times enhanced Verdet constant compared to the host glass. Prima facie observations exemplify the significant enhancement in Verdet constant of Q-dot glass nanocomposites and will have potential application in magneto-optical devices. [ABSTRACT FROM AUTHOR]

Abstract We report on facile preparation of Tellurium (Te)-reduced graphene oxide (rGO) electrodes for evaluation of electrochemical parameters. Initially, Te (0.5–11w/w %) was, in-situ, incorporated while reduction of graphene oxide. In material analysis, 1% Te optimised C/O ratio by rearrangement of C(O)O, separating oxygen from graphene plane, and self-oxidation. Te O bridging acted as an ideal strain buffer that modified nature of conjugation, folding, and exfoliated rGO sheets advantageous for pseudo-capacitive action. Electrochemical analysis, showed substantial increase in specific capacitance, C sp (@5 mV/s), for 1% Te-rGO, to 460 F/g from base rGO (270 F/g) with increase in charge-discharge time (CD@0.5A/g) 15 (rGO) to 100 s (Te-rGO). For two electrodes, CV (285 F/g @ 5 mV/s) and CD (260 F/g @0.25A/g) data was in well agreement with greatest CD ∼ 250 s for (1%). The CD time was retarded by a factor of six in both electrode studies, at 1%. The estimated energy, E D (Wh/kg), and power density, P D (W/kg), indicated that, both electrodes were at the interface of battery and electrode double layer capacitor (EDLC) region on Ragone plane. However, 1%Te-rGO at low P D (250) and high E D (8) have battery-like behaviour, whereas, at high P D (1002) and low E D (5) showed pseudo-capacitive action. Investigations on Nyquist, ac complex capacitance (Bode), and phase plots quantified contribution of impedances offered by surface, interface (electrolyte/active electrode/collector), charge transfer, and ions. Te-rGO showed excellent cycle stability 100% even after 2500 cycles @ 1A/g. By and large, 1% Te showed superior pseudo capacitive performance compared over high Te % and base rGO. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Self-assembled 3D hierarchical Bi2W1−xMoxO6 heterostructures with varying x (x = 0, 0.2, 0.4, 0.6, 0.8 or 1.0) with different morphologies were synthesised via a facile one-pot solvothermal method and their photocatalytic activity towards the oxygen evolution reaction (OER) from water under natural sunlight was tested. The structural properties of Bi2W1−xMoxO6 were studied by the X-ray diffraction (XRD) technique, which showed an orthorhombic Aurivillius layered crystal structure. The microstructural features were examined by FE-SEM and FE-TEM techniques which showed that the morphology of Bi2WO6 varies with substitution of Mo and each morphological structure grows via the assembly of tiny nanoparticles of size 50 nm. The effective substitution of Mo in Bi2WO6 extends the optical absorption towards the visible region. The substitution of Mo in place of W was confirmed by X-ray photoelectron spectroscopy. The photocatalytic activities were evaluated by OER under solar light irradiation. The sample Bi2W0.6Mo0.4O6 (S3) shows enhanced photocatalytic activity for OER from aqueous AgNO3 solution (652 μmol h−1 g−1) which is higher than for pristine Bi2MoO6 or Bi2WO6 photocatalysts. Enhanced photocatalytic activity can be attributed to the extended absorption in the visible light region, which enhances the photocatalytic efficiency of the photocatalysts. More significantly, the 3D intrinsically layered nanosheet structure based morphology, and the unique band structure are beneficial for efficient charge transfer, which enhances the photocatalytic activity. This work demonstrates an effective strategy for developing an active photocatalyst with greater utilization of solar light. [ABSTRACT FROM AUTHOR]

Abstract The synthesis of nitrogen doped orthorhombic niobium oxide nanoplates/reduced graphene oxide composites (N Nb 2 O 5 /rGO) and their photocatalytic activity towards hydrogen generation from water and H 2 S under natural sunlight has been demonstrated, uniquely. Nanostructured N Nb 2 O 5 /rGO is synthesized by in situ wet chemical method using urea as a source of nitrogen and optimized by varying percentage of graphene oxide (GO). X−ray diffraction (XRD) study reveals that N Nb 2 O 5 have orthorhombic crystal structure with crystalline size, 35 nm. Further, X−ray photoelectron spectroscopy (XPS) confirm the presence of nitrogen and rGO in N Nb 2 O 5 /rGO nanocomposite. Morphological features of (N Nb 2 O 5 /rGO) were examined by FE−SEM and FE−TEM showed Nb 2 O 5 nanoplates of diameter 25–40 nm anchored on 2D rGO. Diffuse reflectance spectra depicts the extended absorbance in the visible region with band gap of 2.2 eV. Considering the band gap in the visible region, the photocatalytic hydrogen generation from water and H 2 S has been performed. The 1 wt % rGO hybridized N Nb 2 O 5 (S2) exhibited superior photocatalytic hydrogen generation (537 μmol/h) from water and (1385 μmol/h) from H 2 S under sunlight. The improved photocatalytic activity is attributed due to an extended absorbance in the visible region, modified electronic structure upon doping and formation of well defined N Nb 2 O 5 /rGO interface, provides large surface area, accelerates the supression of electron and hole pairs recombination rate. In our opinion, this works may provides facile route for energy efficient and economic approach for fabrication of N Nb 2 O 5 /rGO nanocomposites as a visible light active photocatalyst. Graphical abstract Here, we report the in situ preparation of nitrogen doped niobium oxide/reduced graphene oxide nanocomposites for hydrogen production from toxic H 2 S and water under natural sunlight has been demonstrated for the first time. The enhanced photocatalytic activity is attributed due to reduced band gap and N Nb 2 O 5 /rGO interface helps to reduce charge carrier's recombination rate. Image 1 Highlights • In-situ N Nb 2 O 5 /rGO oxide has been synthesized. • Due to nitrogen doping band gap reduced to 3.4 to 2.2 eV. • Interaction between N Nb 2 O 5 and RGO leads to change in band structure of Nb 2 O 5. • N Nb 2 O 5 /rGO used as photocatalyst for efficient hydrogen generation. • Single step approach makes this process commercially scalable and energy efficient. [ABSTRACT FROM AUTHOR]

Spherically shaped plasmonic Au nanoparticles (NPs) of size 10 nm (±4 nm) have been decorated on TiO2 NPs for the synthesis of Au@TiO2 composites via an aqueous sol–gel method. The effects of the Au concentration on the optical properties, structural surface properties and photocatalytic activity have been investigated. The optical study indicated characteristics of the surface plasmon resonance (SPR) of Au NPs, which greatly red shifted the photo-absorption from UV to visible light. A Tauc plot showed a downward shift in the band gap energy due to the creation of a metal–semiconductor Schottky junction at the nano Au@TiO2 surface. The well crystallized mixed (anatase and rutile) TiO2 phase formation was investigated using X-ray diffraction studies. The decrease in the photoluminescence (PL) intensity with Au loading indicated an increase in the charge carrier separation. The porous nature of the synthesized photocatalyst material was observed in both Field Emission Scanning Electron Microscopy (FESEM) and Field Emission Transmission Electron Microscopy (FETEM). The homogeneous distribution of Au NPs over the entire TiO2 surface was examined using FETEM and was also confirmed by elemental mapping with STEM. The broadening and shifting of the Raman peak from 143.2 cm−1 to 144.7 cm−1 indicated the generation of crystalline defects such as vacancies and interstitial rearrangement, which may act as trapping sites for electrons. BET surface measurements revealed that the surface area increased from 29.19 m2 g−1 for bare TiO2 to 60.05 m2 g−1 for 2% (w/w) Au loading on TiO2. The synthesized porous Au@TiO2 composites exhibited a high photocatalytic activity for the splitting of H2O under natural solar radiation with the H2 generation rate of 399 μmol/0.1 g h−1, which is much higher than 132 μmol/0.1 g h−1 demonstrated by pristine TiO2 NPs. Along with the hydrogen (H2) generation via water splitting, photocatalytic Rhodamine-B degradation and the kinetics of the reaction were investigated in solar light. The rate was observed to be due to a pseudo-first order reaction. [ABSTRACT FROM AUTHOR]

The synthesis of orthorhombic nitrogen-doped niobium oxide (Nb2O5−xNx) nanostructures was performed and a photocatalytic study carried out in their use in the conversion of toxic H2S and water into hydrogen under UV-Visible light. Nanostructured orthorhombic Nb2O5−xNx was synthesized by a simple solid-state combustion reaction (SSCR). The nanostructural features of Nb2O5−xNx were examined by FESEM and HRTEM, which showed they had a porous chain-like structure, with chains interlocked with each other and with nanoparticles sized less than 10 nm. Diffuse reflectance spectra depicted their extended absorbance in the visible region with a band gap of 2.4 eV. The substitution of nitrogen in place of oxygen atoms as well as Nb–N bond formation were confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. A computational study (DFT) of Nb2O5−xNx was also performed for investigation and conformation of the crystal and electronic structure. N-Substitution clearly showed a narrowing of the band gap due to N 2p bands cascading above the O 2p band. Considering the band gap in the visible region, Nb2O5−xNx exhibited enhanced photocatalytic activity toward hydrogen evolution (3010 μmol h−1 g−1) for water splitting and (9358 μmol h−1 g−1) for H2S splitting under visible light. The enhanced photocatalytic activity of Nb2O5−xNx was attributed to its extended absorbance in the visible region due to its electronic structure being modified upon doping, which in turn generates more electron–hole pairs, which are responsible for higher H2 generation. More significantly, the mesoporous nanostructure accelerated the supression of electron and hole recombination, which also contributed to the enhancement of its activity. [ABSTRACT FROM AUTHOR]

Abstract: The one dimensional Zinc Selenide/Zinc Oxide (ZnSe/ZnO) nano‐heterostructures were prepared using solvo/hydrothermal reaction technique with varying concentration of ZnSe. The prepared nano‐heterostructures were characterized with various techniques. X‐ Ray Diffraction (XRD) indicates the formation of cubic ZnSe and hexagonal phase of ZnO. Field Emission Scanning Electron Microscopy (FESEM) depicts the formation of rod shaped ZnO nanostructures decorated with spherical nanoparticles of ZnSe. Field Emission Transmission Electron Microscopy (FETEM) validates the formation ZnO nanorods of size 30–40 nm along with spherical ZnSe (25‐30 nm) nanostructures. The UV‐Visible absorption spectra analysis clearly depicts the extended absorbance in the visible region. Photoluminescence study indicates the sharp band edge emission peak at 390 nm and broad peak at 475 nm. With further increase in ZnSe concentration, the intensity of band edge emission peak decreases due to the vacancy defects. The photocatalytic performance of prepared ZnSe/ZnO nano‐heterostructure was evaluated by studying the hydrogen (H2) generation via water (H2O) splitting under UV‐Visible light. The ZnSe/ZnO (10:90 weight ratio) shows 491 μmol of H2 generation after 4 hours irradiation. With increase in amount of ZnSe upto 10 mol%, the H2 evolution was also enhanced due to narrowing of the band gap and suppression of recombination rate of charge carriers. [ABSTRACT FROM AUTHOR]

In this report, CdS nanoparticles have been grown on the surface of CdWO 4 nanorods via an in-situ approach and their high photocatalytic ability toward dye degradation and H 2 evolution from H 2 S splitting under visible light has been demonstrated. The structural and optical properties as well as morphologies with varying amount of CdS to form CdS@CdWO 4 have been investigated. Elemental mapping and high resolution transmission electron microscopy (HRTEM) analysis proved the sensitization of CdWO 4 nanorods by CdS nanoparticles. A decrease in the PL emission of CdWO 4 was observed with increasing amount of CdS nanoparticles loading possibly due to the formation of trap states. Considering the band gap in visible region, the photocatalytic study has been performed for H 2 production from H 2 S and dye degradation under natural sunlight. The steady evolution of H 2 was observed from an aqueous H 2 S solution even without noble metal. Moreover, the rate of photocatalytic H 2 evolution over CdS modified CdWO 4 is ca. 5.6 times higher than that of sole CdWO 4 under visible light. CdS modified CdWO 4 showed a good ability toward the photo-degradation of methylene Blue. The rate of dye degradation over CdS modified CdWO 4 is ca. 7.4 times higher than that of pristine CdWO 4 under natural sunlight. With increase in amount of CdS nanoparticle loading on CdWO 4 nanorods the hydrogen generation was observed to be decreased where as dye degradation rate is increased. Such nano-heterostructures may have potential in other photocatalytic reactions. [ABSTRACT FROM AUTHOR]

The preparation of nanostructured hierarchical Mn 1−x Ni x Co 2 O 4 metal oxides as efficient supercapacitors of different structures and configurations especially for the miniaturized electronics is still a challenge. In this context, we report template free facile hydrothermal synthesis of hierarchical nanostructured Mn 1−x Ni x Co 2 O 4 with excellent supercapacitive performance. Significantly, the morphology of pure MnCo 2 O 4 transformed from 3D microcubes to 1D nanowires with incorporation of Ni. The electrochemical study shows highest specific capacitance i.e. 1762 F/g for Mn 0.4 Ni 0.6 Co 2 O 4 with high cycling stability of 89.2% which is much higher than pristine MnCo 2 O 4 and NiCo 2 O 4 . Later, asymmetric capacitor has been fabricated successfully using Mn 0.4 Ni 0.6 Co 2 O 4 nanowires as positive electrode and activated carbon (AC) as negative electrode in a KOH aqueous electrolyte. An asymmetric cell could be cycled reversibly in the high-voltage range of 0–1.5 V and displays intriguing performances with a specific capacitance of 112.8 F/g (6.87 F/cm 3 ) and high energy density of 35.2 Wh/kg (2.1 mWh/cm 3 ). Importantly, this asymmetric capacitor device exhibits an excellent long cycle life along with 83.2% specific capacitance retained after 2000 cycles. [ABSTRACT FROM AUTHOR]

Ag 3 PO 4 is a good photocatalyst but ubiquitously known for its photocorrosion problem during photocatalytic reaction. Therefore, stabilization of Ag 3 PO 4 with retaining its fundamental properties has immense importance. With this motivation, we designed Ag 3 PO 4 glass nanocomposite to resolve the problem of photocorrosion. Moreover, the effect of size quantization on photocatalytic activity has also been demonstrated by growing the cubic Ag 3 PO 4 nanoparticles with size in the range of 3–9 nm in glass matrix via melt and quenching method. The band gap of Ag 3 PO 4 has been tuned (2.56–2.25 eV) in glass matrix with respect to size. Considering the size tunable band gap of Ag 3 PO 4 glass nanocomposite within visible region, it is demonstrated as a photocatalyst for hydrogen (H 2 ) production from copious hazardous waste H 2 S. The utmost H 2 production i.e. 3920.4 μmol h −1 g −1 is obtained using 1 gm of Ag 3 PO 4 glass nanocomposite powder. The apparent quantum yield for H 2 production is calculated to be 5.51% for Ag 3 PO 4 glass nanocomposite. Interestingly, presence of plasmonic Ag was also observed in Ag 3 PO 4 glass nanocomposite which contributes for H 2 production through enhanced light absorption, efficient charge separation and improved stability. Recycling study of sample reveals stable H 2 production efficiency and good stability of the photocatalyst. Surprisingly, catalyst can be reused many times and recovery of catalyst is possible just rinsing with distilled water. All these results demonstrate directly the feasibility of designing a new generation photocatalysts. [ABSTRACT FROM AUTHOR]

Herein, we report the field electron emission investigations on template free solvothermally synthesized layered MoS 2 nanosheets as well as novel phase of CdMoS 4 nanoflowers at the base pressure of ∼1 × 10 −8 mbar. The turn-on field, threshold field and maximum emission current densities for both MoS 2 and CdMoS 4 are strongly influenced by thermal annealing in inert atmosphere. The turn on field, required to draw emission current density of 1 μA/cm 2 is found to be 5.8 and 3.2 V/μm for pristine and annealed MoS 2 at 400 °C. In case of as prepared and annealed CdMoS 4 sample the turn on field values are found to be ∼6.2 and 5.0 V/μm, respectively. The emission current versus time ( I – t ) plot measured at the preset current values of ∼1 μA for pristine and annealed sample indicates stable operation of the emitter. The emission current fluctuations for annealed sample are observed to be less as compared with the pristine sample due to conditioning of the emitter, thereby showing highly stable nature of emitter. Thus, the present result demonstrates the potential of annealed MoS 2 nanosheets and CdMoS 4 nanoflowers as an emerging materials for micro/nanoelectronics and flat panel field emission display applications. [ABSTRACT FROM AUTHOR]

In this study, the synthesis of silver-zinc oxide (Ag-ZnO) nanostructures with a plant-extract-mediated hydrothermal method was investigated. The eco-friendly plant extract Azadirachta indica (Neem) was used as a reducing agent. The X-ray diffraction patterns showed the formation of face-centered cubic (fcc) Ag nanoparticles (NPs) and a wurtzite ZnO structure. An optical study of these nanostructures revealed two absorption edges: one at 393 nm corresponding to ZnO and the other at approximately 440 nm corresponding to Ag. A morphology study showed that hierarchical ZnO nanostructures were decorated with 10–50-nm-diameter Ag NPs. The formation and growth mechanism were also examined. A photoelectrochemical study was performed to investigate the electronic interactions between the ZnO and Ag NPs in the photoanode upon exposure to light. The Ag NPs act as electron acceptors, inhibiting electron–hole recombination. The photocatalytic activity of the Ag-ZnO nanostructures was examined by observing the degradation of aqueous methylene blue (MB) dye under natural sunlight. The apparent rate constant determined for the photocatalytic degradation of MB by the Ag-ZnO nanostructures was 5.9668 × 10 −2 min −1 , which was faster than that of the untreated ZnO nanostructures (2.527 × 10 −2 min −1 ). This plant-extract-mediated synthetic route could also be applied to the synthesis of other Ag-semiconductor oxide nanostructures. [ABSTRACT FROM AUTHOR]

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

Three dimensional (3D) hierarchical nanostructures of orthorhombic Bi2WO6 with unique morphologies were successfully synthesized by a solvothermal method. The precursor concentration plays a key role in the architecture of the hierarchical nanostructures. A peony flower-like morphology was obtained at higher precursor concentrations, and a red blood cell (RBC)-like morphology with average diameter of 1.5 μm was obtained at lower concentrations. These hierarchical nanostructures were assembled by self-alignment of 20 nm nanoplates. As their band gap is in the visible region, the photocatalytic activity of the Bi2WO6 hierarchical nanostructures for the production of hydrogen from glycerol, and the degradation of rhodamine B (RhB) and methylene blue (MB) under ambient conditions in the presence of solar light was investigated. The Bi2WO6 with peony flower morphology was observed to be the most efficient photocatalyst (H2: 7.40 mmol h-1 g-1, kRhB: 0.240 and kMB: 0.100) of the reported nanostructures. The higher activity of the peony flowers was due to their porous nature, high surface area and lower band gap. Such unique 3D nanostructures of Bi2WO6 have been fabricated for the first time, and their use as photocatalysts in the production of hydrogen from glycerol has hitherto not been attempted. These nanostructures may have potential in ferroelectric, piezoelectric, pyroelectric and nonlinear dielectric applications. [ABSTRACT FROM AUTHOR]

A well-defined CdS-ZnO heteroarchitecture has been synthesized via a facile single-step hydrothermal approach. The morphological and structural studies reveal the formation of 3D nano-architectures, in which self-assembled ZnO nanorods (diameter ~50 nm) are well decorated with single crystalline CdS nanoparticles (size ~10 nm). The CdS-ZnO heteroarchitecture exhibits a remarkable change in the optical absorption due to the surface modification of ZnO nanorods by CdS. Surprisingly, under identical reaction conditions, the global ZnS nanoparticles are selectively grown at the apex of ZnO nanorods on the Zn substrate. Furthermore, a plausible growth mechanism has been presented on the basis of experimental results. Interestingly, the CdS-ZnO heteroarchitecture shows enhanced field emission properties such as low turn-on field, high emission current density and better current stability in comparison to other ZnO-based nanostructures. The present CdS-ZnO heteroarchitecture could be extended to other potential applications, such as chemical sensors, photodetectors, optoelectronic devices, and photocatalysts. [ABSTRACT FROM AUTHOR]

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

6,13-Pentacenequinone (PQ), an intermediate for an organic semiconductor pentacene, was synthesized by single step solvent free solid state reaction at room temperature under ambient conditions which is hitherto unattempted. The phase purity has been confirmed by XRD and NMR. Optical study showed the absorption at 390 and 412 nm attributed to the π-π* and n-π* transitions, respectively. Cyclic voltammetry indicates the semiconducting nature of PQ. having a band gap of 3 eV. The photoluminescence study revealed emissions at 408 and 432 nm. Considering the good thermal stability and absorption well within visible region, wisely, PQ. has been used as a photocatalyst for the hydrogen production under solar light Surprisingly we observed the utmost hydrogen evolution i.e. 4848 μmol/h/0.1 g (quantum efficiency 6.8%). The repeatability and reusability study confirmed the stability of the photocatalyst. The confirmation of the photocatalytic effect was also confirmed using methylene blue (MB) dye degradation under natural sunlight The observed rate constant (Kapp) for photocatalytic MB degradation was 1.60 × 10-2 min-1. The use of an organic photocatalyst for hydrogen production has been demonstrated for the first time. This novel organic photocatalyst can also be explored for water splitting. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide is a copious gas produced in refineries (15–20%) as well as billions of tons produced as a by-product in alkali industries. Selectively, only 5% has been utilised for the Claus process to produce liquid sulfur and it is also well known for its uneconomical and environmental problems. Here, we have demonstrated a significant green approach for conversion of poisonous H2S into H2 by stable cubic bismuth (Bi0) quantum dot–glass nanosystems using solar light as the energy source. Previously, metal oxides and sulfides have been demonstrated as solar light photocatalysts. However, a unique bismuth quantum dot–glass nanosystem has been designed where cubic phase bismuth quantum dots of size 1–2 nm are grown in the germanate glass matrix successfully. The presence of bismuth (Bi0) was confirmed by XRD, Raman, TEM and X-ray photoelectron spectroscopy (XPS). The glass nanosystem shows quantum confinement with variation of the band gap from 2.95–1.51 eV. Considering the broad absorption from visible to near IR, we used this glass nanosystem as a solar light active photocatalyst and hydrogen production with respect to the quantum confinement of bismuth (Bi0) quantum dots has been demonstrated for the first time. The photocatalytic activity for hydrogen production using glass nanosystems having bismuth quantum dot sizes of 1–2 nm and 3–6 nm was measured under solar light and prima fascia observations revealed that the glass nanosystems with very small quantum dots (1–2 nm) showed enhanced hydrogen evolution (11 541 μmol h−1 g−1) from H2S. The hydrogen evolution obtained is much higher than for previously reported visible light active nanostructured sulfide/oxide or embedded glass nanosystems. The glass nanosystems were also used for water splitting and show evolution of hydrogen without any co-catalyst. It is noteworthy that the quantum dot–glass photocatalyst is highly stable and catalyst regeneration is quite easy and fast. Hence, the QD-bismuth–glass nanocomposites have significant advantages over normal nanosized powder catalysts. Such unique glass nanosystems will also have great potential in photonics and optoelectronic applications. [ABSTRACT FROM AUTHOR]

In the present investigation, silver vanadium sulfide (SVS) anchored by PANI matrix nanocomposite (NC) was synthesized by in situ polymerization of aniline. For the preparation of NC, aniline, silver nitrate, ammonium metavanadate and thiourea (TU) were used as the precursors. TU was used as a metal ion complex forming agent as well as a source of sulfur. Fourier transform infrared (FTIR) and energy dispersive X-ray (EDS) spectroscopic investigation indicate the presence of two layers: outer layer is of PANI, and middle layer is of SVS. Field emission scanning electron microscopy (FESEM), high resolution transmission electron microscope (HRTEM) and atomic force microscopy (AFM) study shows good coverage of PANI on the surface of SVS spherical particles. The presented NCs are found to be an effective and facile technique for improving the electrochemical performance and stability, than PANI alone, for supercapacitors. The capacitance of PANI-anchored SVS is 440 F g−1 and that of PANI is found to be 128 F g−1. The dependence of the impedance behavior of the PANI-anchored SVS nanospheres NCs film was studied systematically. The results are interpreted on the basis of an Adatom model. Moreover, the formation of binary transition metal sulfides has been demonstrated at optimum conditions. [ABSTRACT FROM AUTHOR]

Hierarchical Ag–ZnO heterostructures have been synthesized via a template free single step hydrothermal method. Structural and morphological studies reveal the formation of heterostructures comprised of Ag nanoparticles (∼20 nm) organized on tapered ZnO nanorods under the prevailing experimental conditions. A plausible reaction and growth mechanism has been discussed. Furthermore, the hierarchical creation of ZnO with Ag as a relatively low work function material offers an effective approach to tailor its field emission properties. The field emission studies reveal a remarkable low turn-on field of ∼ 1 V μm−1, corresponding to an emission current density of ∼10 μA cm−2, and an emission current density of ∼400 μA cm−2 has been drawn at an applied field of 2.24 V μm−1. In addition, the Ag–ZnO heterostructures exhibit a good emission current stability at the pre-set value of ∼1 and 4 μA over a duration of 3 h. The enhancement of the field emission characteristics resulting from Ag nanoparticles decorating the tapered ZnO nanorods is discussed on the basis of band structure modifications. The ease of the synthesis route and the remarkable field emission properties offer Ag–ZnO heterostructures as a promising electron source for high current density applications. [ABSTRACT FROM AUTHOR]

We have demonstrated a template-free large-scale synthesis of nanostructured CdxZn1-xS by a simple and a low-temperature solid-state method. Cadmium oxide, zinc oxide, and thiourea in various concentration ratios are homogenized at moderate temperature to obtain nanostructured CdxZn1-xS. We have also demonstrated that phase purity of the sample can be controlled with a simple adjustment of the amount of Zn content and nanocrystalline CdxZn1-xS (x = 0.5 and 0.9) of the hexagonal phase with 6-8 nm sized and 4-5 nm sized Cd0.1Zn0.9S of cubic phase can be easily obtained using this simple approach. UV-vis and PL spectrum indicate that the optical properties of as synthesized nanostructures can also be modulated by tuning their compositions. Considering the band gap of the nanostructured CdxZn1-xS well within the visible region, the photocatalytic activity for H2 generation using H2S and methylene blue dye degradation is performed under visible-light irradiation. The maximum H2 evolution of 8320 μmol h-1g-1 is obtained using nanostructured Cd0.1Zn0.9S, which is four times higher than that of bulk CdS (2020 μmol h-1 g-1) and the reported nanostructured CdS (5890 μmol h-1g-1). As synthesized Cd0.9Zn0.1S shows 2-fold enhancement in degradation of methylene blue as compared to the bulk CdS. It is noteworthy that the synthesis method adapted provides an easy, inexpensive, and pollution-free way to synthesize very tiny nanoparticles of CdxZn1-xS with a tunnable band structure on a large scale, which is quite difficult to obtain by other methods. More significantly, environmental benign enhanced H2 production from hazardous H2S using CdxZn1-xS is demonstrated for the first time. [ABSTRACT FROM AUTHOR]

Abstract: Ink-jet printed, intrinsically conducting polymer (ICP), polyaniline have been used for humidity sensing at room temperature. Polyaniline based, aqueous ink-jet printable ink has been synthesized by single step, chemical oxidative polymerization technique. Sulphonic acids were used as a dopant during the in situ polymerization process. This is a single step polymerization process for the direct synthesis of conducting emeraldine salt phase of the polymer as an ink formulation. The synthesized polyaniline ink was further characterized by spectroscopic (UV–visible and FT-IR) analysis which confirmed the presence of conducting emeraldine salt phase of the polymer. The viscosity of the ink was measured by using Brook-field viscometer. The successive trials were performed for the printing of IDT pattern on the flexible, untreated polymer substrate using HP ink-jet-printer. The printed sensor was subjected for the humidity sensing measurements. The change in the resistance with change in the %RH was observed. It is suggested that the increase in conductivity at high humidity may be related to a vapour-induced change in the transfer of charge carriers between the polymer chains. The synthesized polyaniline based ink can also be considered as a good candidate for variety of ink-jet printed low cost electronics devices. [Copyright &y& Elsevier]

Abstract: In this article, we focused on cadmium sulphide (CdS) nanoparticles (NPs) sensitized rutile TiO2 microspheres (TMS) as a photoanode, which has been studied systematically. Hydrothermally grown TMS are sensitized with CdS NPs by simple and cost effective successive ionic layer adsorption and reaction (SILAR) technique. The synthesized CdS and CdS-TMS samples were characterized by Fourier Transform Raman Spectroscopy (FT-Raman), X-ray photoelectron spectroscopy (XPS) and FESEM characterization techniques. The CdS and CdS-TMS samples were further used for their photoelectrochemical (PEC) performance and were tested in Na2Slyph name="sbnd" />S and Na2S electrolytes respectively. When CdS nanoparticles are coated on TMS, it exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (JSC) 2.75mA/cm2. The Judiciously optimized CdS-decorated TiO2 morphology will be helpful for effective light-harvesting and fast electron-transfer from CdS to conduction band (CB) of TiO2. The highest power conversion efficiency of semiconductor-sensitized solar cells (SSSCs) i.e. CdS NP-sensitized TMS for the first time is 2.34% which is much higher than the bare CdS sample. [Copyright &y& Elsevier]

Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48eV and it shifted to 3.14eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6nm and 8–12nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. [Copyright &y& Elsevier]

We have investigated an economical green route for the synthesis of a p-type N-doped ZnO photocatalyst by a wet chemical method. Significantly, hazardous H2S waste was converted into eco-friendly hydrogen energy using the p-type N-doped ZnO photocatalyst under solar light, which has previously been unattempted. The as-synthesized p-type N-doped ZnO shows a hexagonal wurtzite structure. The optical study shows a drastic shift in the band gap of the doped ZnO in the visible region (3.19–2.3 eV). The doping of nitrogen into the ZnO lattice is conclusively proved from X-ray photoelectron spectroscopy analysis and Raman scattering. The morphological features of the N-doped ZnO are studied from FESEM, TEM and reveal particle sizes to be in the range of ∼4–5 nm. The N-doped ZnO exhibits enhanced photocatalytic hydrogen generation (∼3957 μmol h−1) by photodecomposition of hydrogen sulfide under visible light irradiation, which is much higher as compared to semiconductor metal oxides reported so far. It is noteworthy that a green catalyst is investigated to curtail H2S pollution along with production of hydrogen (green fuel) using solar light, i.e., a renewable energy source. The green process investigated will have the potential to synthesize other N-doped metal oxides. [ABSTRACT FROM AUTHOR]

It is renowned that the oil refineries are venting off 15–20% H2S and hardly 5% has been utilized to produce sulphur and water ubiquitously by the Claus process. This process is un-economical, highly polluting and by-products create further acute environmental problems. Here, we have demonstrated the significant approach of the conversion of poisonous H2S into H2 by stable orthorhombic QD–CdS–glass nanosystems using a most abundant solar light energy source. This is an eco-friendly process that produces cheaper hydrogen as well as degrades organic dyes efficiently. We have investigated a novel, Q-CdS (highly mono-dispersed) germanate glass nanocomposite. Surprisingly, the CdS quantum dots (QDs) obtained in the glass matrix are orthorhombic in structure and highly thermally stable. Generally, the orthorhombic CdS powder is in a metastable state i.e. unstable at normal conditions. The quantum dots of 4–14 nm size of CdS were grown for the first time in the germanate glass. The confinement of orthorhombic CdS was studied using UV-Vis spectroscopy and photoluminescence. There is a drastic change in the band gap of glass without CdS nanocrystals (3.16 eV) as compared to the glass with orthorhombic CdS QDs (2.25 eV). Considering the suitable band gap of the CdS quantum dot–glass for the visible light absorption, the studies of the photocatalytic activity for H2 generation and dye degradation was performed under visible light irradiation for the first time. High H2 evolution, i.e. 3780 μmol h−1, was obtained, which is much higher than earlier reported for CdS nano-powder. More significantly, the catalyst is stable and easily regenerated as compared to other normal catalysts. The glass nanocomposite also showed excellent methylene blue degradation under visible light irradiation. Such orthorhombic QD–CdS–glass nanocomposites have great significance because they have potential applications in solar cell, LED and other optoelectronic devices. [ABSTRACT FROM AUTHOR]

Abstract: Silver–polyaniline (Ag–PANI) nanocomposite was synthesized by in situ polymerization method using ammonium persulfate (APS) as an oxidizing agent in the presence of dodecylbenzene sulfonic acid (DBSA) and silver nitrate (AgNO3). The as synthesized Ag–PANI nanocomposite was characterized by using different analytical techniques such as UV–visible (UV–vis) and Fourier transform Infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV–visible spectra of the synthesized nanocomposite showed a sharp peak at ∼420nm corresponding to the surface plasmon resonance (SPR) of the silver nanoparticles (AgNPs) embedded in the polymer matrix which is overlapped by the polaronic peak of polyaniline appearing at that wavelength. Nanowires of Ag–PANI nanocomposite with diameter 50–70nm were observed in FE-SEM and TEM. TGA has indicated an enhanced thermal stability of nanocomposite as compared to that of pure polymer. The Ag–PANI nanocomposite has shown an antibacterial activity against model organisms, a gram positive Bacillus subtilis NCIM 6633 in Mueller–Hinton (MH) medium, which is hitherto unattempted. The Ag–PANI nanocomposite with monodispersed AgNPs is considered to have potential applications in sensors, catalysis, batteries and electronic devices. [Copyright &y& Elsevier]

It is quite well-known that refineries are producing huge amount of H2S which has been used to produce sulphur and water using the well-known Claus process. This process is not an economically viable process, due to the high-cost chemical process and creates further acute environmental problems. Therefore, we have demonstrated the conversion of poisonous H2S into H2 using an ecofriendly phocatalysis process which is a green unconventional energy source. We have investigated ecofriendly nanostructured ZnIn2S4 photocatalyst to produce hydrogen from H2S using solar light. We also demonstrate the controlled synthesis of hierarchical nanostructured ZnIn2S4 using a facile hydrothermal method. The morphologies obtained have been greatly influenced by the presence of triethylamine (TEA) with various concentrations during the reaction. Surprisingly, a highly crystalline hexagonal layer structured ZnIn2S4 was obtained instead of cubic spinel. The hierarchical nanostructure, i.e. marigold flower-like morphology, was obtained without any surfactant. The thin and transparent petals self-assembled to form the unique nanostructured marigold flower. The highly crystalline puffy marigold flowers and nanoplates/nanostrips were obtained using TEA-assisted hydrothermal synthesis. Optical study shows the band gap in the range of 2.34–2.48 eV. Considering the band gap in the visible region, ZnIn2S4 is used as photocatalyst for hydrogen production from hydrogen sulphide under solar light which is hitherto unattempted. The constant photocatalytic activity of hydrogen evolution, i.e. 5287 μmol h−1, was obtained using such hierarchical nanostructured ZnIn2S4 under visible light irradiation. It is noteworthy that the H2 evolution rate obtained is much higher compared to earlier reported photocatalysts. Considering the significance of morphologies for photocatalytic application, the formation mechanism has also been furnished. The unique hierarchical nanostructured ZnIn2S4 ternary semiconductor having hexagonal layer will have potential applications in solar cells, LEDs, charge storage, electrochemical recording, thermoelectricity and other prospective electronic and optical devices. [ABSTRACT FROM AUTHOR]

It is quite well-known that refineries are producing huge amount of H2S which has been used to produce sulphur and water using the well-known Claus process. This process is not an economically viable process, due to the high-cost chemical process and creates further acute environmental problems. Therefore, we have demonstrated the conversion of poisonous H2S into H2using an ecofriendly phocatalysis process which is a green unconventional energy source. We have investigated ecofriendly nanostructured ZnIn2S4photocatalyst to produce hydrogen from H2S using solar light. We also demonstrate the controlled synthesis of hierarchical nanostructured ZnIn2S4using a facile hydrothermal method. The morphologies obtained have been greatly influenced by the presence of triethylamine (TEA) with various concentrations during the reaction. Surprisingly, a highly crystalline hexagonal layer structured ZnIn2S4was obtained instead of cubic spinel. The hierarchical nanostructure, i.e.marigold flower-like morphology, was obtained without any surfactant. The thin and transparent petals self-assembled to form the unique nanostructured marigold flower. The highly crystalline puffy marigold flowers and nanoplates/nanostrips were obtained using TEA-assisted hydrothermal synthesis. Optical study shows the band gap in the range of 2.34–2.48 eV. Considering the band gap in the visible region, ZnIn2S4is used as photocatalyst for hydrogen production from hydrogen sulphide under solar light which is hitherto unattempted. The constant photocatalytic activity of hydrogen evolution, i.e.5287 μmol h−1, was obtained using such hierarchical nanostructured ZnIn2S4under visible light irradiation. It is noteworthy that the H2evolution rate obtained is much higher compared to earlier reported photocatalysts. Considering the significance of morphologies for photocatalytic application, the formation mechanism has also been furnished. The unique hierarchical nanostructured ZnIn2S4ternary semiconductor having hexagonal layer will have potential applications in solar cells, LEDs, charge storage, electrochemical recording, thermoelectricity and other prospective electronic and optical devices. [ABSTRACT FROM AUTHOR]

Abstract: In the present investigation, we have demonstrated the synthesis of novel photocatalyst, zinc indium vanadate (ZIV) by solid–solid state route using respective oxides of zinc, indium and vanadium. This novel photocatalyst was characterized using XRD, FESEM, UV-DRS and FTIR in order to investigate its structural, morphological and optical properties. XRD clearly shows the formation of phase pure ZIV of triclinic crystal structure with good crystallinity. FESEM micrographs showed the clustered morphology having particle size between 0.5 and 1μm. Since, optical study showed the band gap around 2.8eV, i.e. in visible region, we have performed the photocatalytic activity of phenol degradation under visible light irradiation. The photodecomposition of phenol by ZIV is studied for the first time and an excellent photocatalytic activity was obtained using this novel photocatalyst. Considering the band gap of zinc indium vanadate in visible region, it will also be the potential candidate for water splitting. [Copyright &y& Elsevier]

Abstract: The organic–inorganic hybrid nanocomposite of polyaniline–V2O5 was synthesized by microwave-assisted hydrothermal method. The nanocomposite was separated by filtration and washed with deionized water. Structural study of nanocomposite was performed using XRD. The microstructural study of nanocomposite performed using field emission scanning electron microscopy (FESEM) shows self-assembled plates with curly petal or tremella-like morphology. The nanocomposite was subjected for spectroscopic (UV–vis and FT-IR) analysis. The UV–vis spectra revealed the presence of conducting emeraldine salt phase of the polymer which was further supported by FT-IR analysis. [Copyright &y& Elsevier]