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In this study, novel hydrothermal ex situ synthesis was adopted to synthesize MoS2/WO3 heterostructures using two different molar ratios of 1:1 and 1:4. The "bottom-up" assembly was successfully developed to synthesize spherical and flaky-shaped heterostructures. Their structural, morphological, compositional, and bandgap characterizations were investigated through XRD, EDX, SEM, UV-Visible spectroscopy, and FTIR analysis. These analyses help to understand the agglomerated heterostructures of MoS2/WO3 for their possible photocatalytic application. Therefore, prepared heterostructures were tested for RhB photodegradation using solar light irradiation. The % efficiency of MoS2/WO3 composites for 30 min irradiation of 1:1 was 91.41% and for 1:4 was 98.16%. Similarly, the % efficiency of 1:1 MoS2/WO3 heterostructures for 60 min exposure was 92.68%; for 1:4, it was observed as 98.56%; and for 90 min exposure, the % efficiency of 1:1 was 92.41%, and 98.48% was calculated for 1:4 composites. The photocatalytic efficiency was further verified by reusability experiments (three cycles), and the characterization results afterward indicated the ensemble of crystalline planes that were responsible for the high efficiency. Moreover, these heterostructures showed stability over three cycles, indicating their future applications for other photocatalytic applications. [ABSTRACT FROM AUTHOR]

Nb 2 O 5 appeared as a promising candidate for a large number of applications. In the present work novel, 3D-hollow hierarchical Nb 2 O 5 superstructures are prepared by self-organization of mesorods. The work emphasizes on the synthesis and detailed investigation of 3D-hollow hierarchical Nb 2 O 5 superstructures, which are attained by two-step, template-free hydrothermal synthesis route. The obtained orthorhombic(T)-Nb 2 O 5 superstructures have shown a high crystallinity, with a wide band gap of 3.1 eV. Among semiconductor oxides Nb 2 O 5 with different morphologies are less explored due to complicated synthesis, growth and nucleation process. Thus, in general, factors involved for self-organized superstructures are not studied in detail. In this context, assembly of T-Nb 2 O 5 superstructures is investigated in depth by applying SEM, TEM and UV/Vis absorption measurements. Based on the realized results a formation mechanism is proposed, which is further strengthened by the time and precursor dependent experiments. In addition, asymmetric supercapacitor properties of T-Nb 2 O 5 superstructures are studied for the first time by using an inorganic electrolyte. The devised T-Nb 2 O 5 superstructures have demonstrated excellent supercapacitor performance. The supercapacitor is operated at a wide potential window of 2.5 V in Na 2 SO 4 electrolyte and exhibited high power density (650 W/Kg), energy density (86 Wh/Kg) with good cycling capability. [ABSTRACT FROM AUTHOR]

A two step, facile surfactant free hydrothermal route was adopted to synthesize Nb 3 O 7 F novel hollow microflowers (NHMF). Time dependent experiments were performed which suggested Nb 3 O 7 F-NHMF were formed due to Ostwald-ripening process. Raman spectroscopy was conducted to understand different vibrational modes of Nb 3 O 7 F-NHMF. Its characteristic band at 692 cm −1 was observed which is associated to NbO 6 octahedron sharing. The bandgap of 3.2 eV was calculated by using UV-VIS-NIR absorption spectrum. Considering importance of layered structures in energy storage applications, hydrogen storage ability of Nb 3 O 7 F-NHMF were measured for the first time. The maximum values of hydrogen absorption for Nb 3 O 7 F-NHMF at 373 K and 473 K were 0.789 wt.% and 1.08 wt.%, respectively. The hydrogen storage measurements revealed the potential of Nb 3 O 7 F-NHMF as prospective material for energy storage applications. [ABSTRACT FROM AUTHOR]

Novel nanoflowers (NNF) of Nb3O7F have been synthesized by a facile template free route without using any surfactant. The evolution of these NNF have been studied by varying different reaction parameters. Using the UV-Vis spectra absorption peak the calculated bandgap was 2.9 eV. Organic dye rhodamine B (RhB) was degraded with average photodegradation efficiency of 87.8%, 94.23% and 99.7% with higher rate constant k = 1.1559, 1.9011 and 3.8862 for 0.005 g, 0.01 g and 0.1 g respectively. The rate constant for 0.1 g was found to be larger than for Nb2O5, commercial TiO2 Degussa P25, carbon modified Nb2O5/TiO2, g-C3N4, Fe2O3/g-C3N4 composites and SnNb2O6. [ABSTRACT FROM AUTHOR]

We report here large scale synthesis of ZnV 2 O 6 nanostructures via facile, template free and cost effective method. For the first time hydrogen storage and supercapacitor properties of ZnV 2 O 6 nanostructures were measured, which were found to be 1.32wt% and 380 F/g, respectively. Electrochemical supercapacitor device was fabricated using three electrode configuration and electrochemical measurements revealed ZnV 2 O 6 nanostructures as a promising candidate for energy storage/conversion material. PL measurements on ZnV 2 O 6 showed a broad emission centered at 392 nm. Our investigation has shown that ZnV 2 O 6 nanostructures has the potential to be used as an energy storage material and in blue optoelectronic devices. [ABSTRACT FROM AUTHOR]

10.3390/catal10101196 5 Dai Y., Lu C., Liang L., Feng N., Wang J. Visible Light Electromagnetic Interaction of PM567 Chiral Dye for Asymmetric Photocatalysis, a First-Principles Investigation. Chen, Linjer, et al. [[6]], developed effective and simple synthetic approach to synthesize uniform CoO@meso-CN@MoS SB 2 sb heterostructures to study the photodegradation under a visible light for organic pollutants. Photocatalysis is a highly promising technique to address the challenges of environmental and energy aspects. [Extracted from the article]

This work focuses on the synthesis of heterostructures with compatible band positions and a favourable surface area for the efficient photocatalytic production of molecular hydrogen (H2). In particular, 3-dimensional Nb2O5/g-C3N4 heterostructures with suitable band positions and high surface area have been synthesized employing a hydrothermal method. The combination of a Nb2O5 with a low charge carrier recombination rate and a g-C3N4 exhibiting high visible light absorption resulted in remarkable photocatalytic activity under simulated solar irradiation in the presence of various hole scavengers (triethanolamine (TEOA) and methanol). The following aspects of the novel material have been studied systematically: the influence of different molar ratios of Nb2O5 to g-C3N4 on the heterostructure properties, the role of the employed hole scavengers, and the impact of the co-catalyst and the charge carrier densities affecting the band alignment. The separation/transfer efficiency of the photogenerated electron-hole pairs is found to increase significantly as compared to that of pure Nb2O5 and g-C3N4, respectively, with the highest molecular H2 production of 110 mmol/g·h being obtained for 10 wt % of g-C3N4 over Nb2O5 as compared with that of g-C3N4 (33.46 mmol/g·h) and Nb2O5 (41.20 mmol/g·h). This enhanced photocatalytic activity is attributed to a sufficient interfacial interaction thus favouring the fast photogeneration of electron-hole pairs at the Nb2O5/g-C3N4 interface through a direct Z-scheme. [ABSTRACT FROM AUTHOR]

This study investigates into the synthesis, characterization, and multifaceted analysis of a composite material comprised of copper vanadium oxide (CVO) and graphitic Carbon Nitride g-C 3 N 4 (GCN). The fabrication of the composite was achieved through wet-chemical method followed by annealing at 600 °C for 3 h, ensuring controlled composition and structure. The characterization process encompassed X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectroscopy, unveiling the composite's crystalline structure, novel nano-rod morphology with decorated flakes, and UV–visible light activation capability. The obtained band gap of approximately 2.7 eV signified the composite's optical properties. Electrochemical analysis, including cyclic voltammetry (CV), highlighted the composite's robust biosensing attributes, particularly in response to ascorbic acid. The conducting and metallic characteristics of the composite enhanced its reactivity, promising applications in biosensors and energy storage devices. This comprehensive investigation elucidates the multifaceted potential of the CVO/GCN nano-composite across diverse optoelectronic realms. [ABSTRACT FROM AUTHOR]

The hierarchical nanostructures (HNs) have engrossed immense attention due to their superior performance in catalysis, electronic and energy storage/conversion devices. The multicomponent transition metal oxides (TMOs) have been pointed out as more promising materials for advanced technological applications as compared to their counter binary oxides. Due to the advantages of hierarchical nanostructures and TMOs we have synthesized novel Zn 2 V 2 O 7 hierarchical nanostructures using template free route. The photoluminescence of the sample exhibited an emission at 553.65 nm which can be useful for light emission devices. The hydrogen storage of Zn 2 V 2 O 7 HNs were measured at 473 K and 573 K with an absorption of 1.21 wt.% and 1.81 wt.%., respectively. These studies point out a new class of nanomaterials for possible applications for energy storage and green emission optoelectronic devices. [ABSTRACT FROM AUTHOR]

Thin films of zinc doped aluminum antimonide (Zn:AlSb) have been dumped on glass substrate using chemical bath deposition method. The morphological, structural, as well as optical properties of deposited thin films are investigated using XRD, optical microscopy, and UV-V is spectroscopy along with four-point probe technique. The XRD results exhibit that Zn is doped in AlSb and maximum grain size has been obtained at 4% Zn-concentration. Optical micrographs of pure and zinc doped aluminum antimonide (AlSb) at different concentrations of Zn have been shown to confirm the doping by observing changes in morphology and it has been observed that optimized films of AlSb are obtained at 4% of Zn-content. The optical bandgap of Zn doped AlSb films at varying concentrations of 0%, 1%, 2%, 3% and 4% has been found to decrease with enhancement in Zn-concentration and values are measured as 1.8, 1.7, 1.6, 1.4, and 1.3 eV respectively. The sheet resistivity also depends on Zn-content and has been observed to decrease as AlSb is doped with Zn, indicating an increase in electrical conductivity. The explored results indicate a significant potential of these deposited thin films to be used in photonics, photocatalysis, and energy industry. [ABSTRACT FROM AUTHOR]

This study is aimed to investigate laser irradiation effects on the surface, structural, and mechanical properties of iron samples. The prepared samples have been treated for multiple exposure times using continuous-wave diode laser with a wavelength of 532 nm in a laboratory environment. The structural as well as surface modifications of laser exposed targets are explored via scanning electron microscope and X-ray diffractometer. The SEM analysis revealed micrometer grain size, exfoliational sputtering, and crater formation, while XRD patterns were used to investigate d-spacing, and grain size of laser exposed samples. The mechanical characteristics of laser-ablated materials were examined using a micro Vickers hardness-tester, and microhardness has been explored as a function of increasing laser exposure time. It has been observed that grain size reduces while hardness of polycrystalline iron increases with increase in exposure time. [ABSTRACT FROM AUTHOR]

In this study, novel hydrothermal synthesis is used to explore the impact of photocatalytic activity on H2 production using an aqueous solution of triethanolamine (TEoA) in TiO2 nanostructures designed with varying molar concentrations of HCl, and the production of molecular hydrogen is explored as a function of molar concentration. A solar simulator is utilized to assess the photocatalytic activities of methyl orange degradation under UV light irradiation and molecular H2 production. Also, XRD patterns and SEM images are explored to show agglomerated nanoparticle formation, and an EDX spectrum is employed to confirm TiO2 compositions. The band gap analysis of produced nanostructures is performed using a UV-Vis spectrometer and is found to be varying in between 2.5 and 3.0 eV, while the maximum methyl orange degradation corresponds to 1.0 M concentration of HCl, indicating an enhanced hydrogen production. To meet the foreseeable future energy crises and worsening environmental challenges, we may need sustainable energy sources, and photocatalysis molecular H2 production offers a viable alternative to fossil fuels that can be employed to tackle future difficulties. [ABSTRACT FROM AUTHOR]

Directional reconstructed CoP-Cu/Co(OH) 2 promotes the synergistic catalysis of NO 3 −RR to deliver satisfactory ammonia production rate (9.91 mmol h−1cm−2) and high Faraday efficiency (99.2 %) with appreciable economic benefits at industrial-level current densities. [Display omitted] • Self-supported CoP-Cu heterojunction is successfully prepared by a simple method. • The reconstructed CoP-Cu/Co(OH) 2 boosted the NO 3 −RR performance via synergistic catalysis. • CoP-Cu/Co(OH) 2 delivers the NH 3 yield rate of 9.91 mmol h−1cm−2 with the FE of 99.2 % at industrial-level current density. • The assembled MEA system can be operated efficiently and stably under industrial conditions. • Techno-economic analysis exhibits appreciable economic benefits of our system. The electrochemical reduction of nitrate (NO 3 −RR) represents a compelling approach for the treatment of wastewater, serving as both a sustainable substitute to the energy-intensive Haber-Bosch process and a viable alternative to direct electroreduction of N 2. However, the process involves multiple electron and proton transfer steps and a complex reaction pathway, leading to low Faraday efficiency and selectivity. Herein, we demonstrated a directional surface reconstruction to generate CoP-Cu/Co(OH) 2 heterojunction for synergistic catalysis of NO 3 −RR. Impressively, a high ammonia generation rate of 9.91 mmol h−1cm−2 and a Faraday efficiency of 99.2 % can be achieved at an industrial-relevant current density of 2 A cm−2. Moreover, the catalyst exhibited exceptional durability, maintaining the activity for 110 h under industrial current density. Such outstanding NO 3 −RR performance can be ascribed to the synergistic catalytic effect among the active sites of Cu, CoP and Co(OH) 2 , as well as the excellent stability of self-supported catalyst. Specifically, Cu and CoP sites synergistically promote the conversion of NO 3 − to NO 2 − and NO 2 − to NH 3. Meanwhile, the partial reconstructed Co(OH) 2 from CoP enhances water dissociation, thereby supplying active hydrogen (*H) essential for NO 3 −RR. When applied to a membrane electrode assembly (MEA) system, CoP-Cu/Co(OH) 2 can deliver satisfactory ammonia production rate with appreciable economic benefits at industrial-level current densities, highlighting its potential for industrial applications. [ABSTRACT FROM AUTHOR]

• Bi 4 O 5 I 2 was successfully fabricated by adding low dosage of KI. • Visible light could be efficiently utilized using Bi 4 O 5 I 2 with biomimetic nanorose structure. • Bismuth-rich can improve the reduction/oxidation ability. • Bi 4 O 5 I 2 degraded 92.3% RhB, showing 4 times higher than that of pure BiOI. A facile chemical precipitation has been successfully developed to fabricate nanoflake BiOI (1.259 g) by adding 1:1 M ratio of Bi (NO 3) 3 ·5H 2 O and 4 mM KI into the mixture of ethylene glycol and distilled water. Interestingly, with addition of 2 mM KI, bismuth-rich oxyiodide (Bi 4 O 5 I 2 , 0.848 g) with nanorose-shaped structure was obtained. In addition, after the collecting the precipitation of Bi 4 O 5 I 2 , the extra 2 mM KI was added in solution, 0.406 g of BiOI (named as BiOI-S) was produced. The quality of the obtained Bi 4 O 5 I 2 and BiOI-S with each 2 mM KI addition is similar as the one step fabrication method using 4 mM KI. The synthesized hierarchical structure Bi 4 O 5 I 2 with nanorose-shaped shows higher band gap energy (1.9 eV) than that of BiOI (1.7 eV), and higher specific surface area (36.9 m2 g−1) than that of BiOI (28.1 m2 g−1). Therefore, Bi 4 O 5 I 2 nanorose-shaped showed superior photo-catalytic performance and degraded 92.3% of rhodamine B, which was 4 times faster than that of the pure BiOI. Our work may provide a facile strategy for efficient photocatalytic activity application in the treatment of water pollution via controlled KI addition. [ABSTRACT FROM AUTHOR]

BiOI is a visible photocatalyst towards organic pollutant. In this work, biomass waste (withered typha grass) was used to fabricate nitrogen-doped hierarchical carbon (NHC) by an one-step carbonization route. Then NHC provided a good carrier to load the BiOI semiconductor materials by a green simple co-precipitation method, after adding NaOH solution, the irregular microspheres BiOI/NHC was gradually etched by OH− to form the tremella-like Bi 4 O 5 I 2 /NHC. The well-defined tremella-like Bi 4 O 5 I 2 /NHC invested adequate interface and high particular surface range (S BET : 66 m2 g−1), which is higher than pure BiOI (22 m2 g−1) and Bi 4 O 5 I 2 (17 m2 g−1). Multiple synergistic effects, such as high S BET can give more dynamic destinations, the special tremella-like structure can assimilate more reflected occurrence light of other nanosheets, low I content can increase the conduction/valence band gap of semiconductor materials and NHC can act as an electron acceptor, making as-prepared Bi 4 O 5 I 2 /NHC composite ideal candidates for photocatalysis. The degradation rate of Bi 4 O 5 I 2 /NHC reaches up to 87.4% of methyl orange in 2 h, which is about 2 times higher than BiOI and Bi 4 O 5 I 2. Therefore, this work gives a technique to link NHC derived from biomass waste to Bi 4 O 5 I 2 with highly-efficiency photocatalytic performance. • N-doped hierarchical carbon (NHC) is obtain from biowaste (cattail grass). • Bi 4 O 5 I 2 with tremella-like structure decorated on NHC. • NHC can act as an electron acceptor to enhance the photocatalytic capacity. • NaOH solution promoted the facile fabrication of Bi 4 O 5 I 2 /NHC. • An one-step, simple and green method is used for photocatalytic composites. [ABSTRACT FROM AUTHOR]

The development of green and clean synthetic techniques to overcome energy requirements have motivated the researchers for the utilization of sustainable biomass. Driven by this desire we choose rice as starting materials source. After the explosion effect, the precursor is converted into puffed rice with a honeycomb-like structures composed of thin sheets. These honeycomb-like macrostructures, effectively prevent the cross-linking tendency towards the adjacent nanosheets during activation process. Furthermore, tuneable micro/mesoporous structures with ultrahigh specific surface areas (S BET ) are successfully designed by KOH activation. The highest S BET of 3326 m 2 g −1 with optimized proportion of small-mesopores is achieved at 850 °C. The rice-derived porous N-doped carbon nanosheets (NCS-850) are used as the active electrode materials for supercapacitors. It exhibites high specific capacitance specifically of 218 F g −1 at 80 A g −1 in 6 M KOH and a high-energy density of 104 Wh kg −1 (53 Wh L −1 ) in the ionic liquid electrolytes. These are the highest values among the reported biomass-derived carbon materials for the best of our knowledge. The present work demonstrates that the combination of “puffing effect” and common chemical activation can turn natural products such as rice into functional products with prospective applications in high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

We propose a novel idea to utilize environment pollutant cigarette ash for energy storage material as electrode of supercapacitors as supercapacitors can deliver high power and reasonable energy densities as compared to batteries which deliver energy as a result of chemical reactions and suffer with low power densities. Keeping in view this advantage and research focus in this field, supercapacitors of cigarette ash were fabricated as energy storage devices. The electrode composed of ash shows specific capacitance of 183.33 F/g at current density of 1 A/g for 1st cycle and 165 F/g for 2000th cycle which indicate its remarkable long-term cyclic stability in Na 2 SO 4 electrolyte. [ABSTRACT FROM AUTHOR]

Highly efficient visible-light-driven WO3/Fe2(WO4)3·10.7H2O porous microplates have been fabricated for the first time by a simple one-step hydrothermal method using sodium tungstate and iron chloride as precursors. The photocatalyst was characterized by employing X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-VIS absorption, photoluminescence (PL), and Fourier transform infrared spectroscopy (FTIR). From the FESEM and TEM analysis, the size of as-prepared porous microplates was estimated to be ca. 2 μm. The as-prepared sample maintained a high specific surface area (96.906 m2 g−1) and showed remarkably high photocatalytic performance (k = 0.06771 min−1) for the degradation of methyl orange (MO) under visible light irradiation. The improved performance of the product was found to be 3.3 times greater than pure WO3 and about 6.7 times greater than that of P25 TiO2. The enhanced optical absorption in the visible region, large specific surface area, suitable band position and efficient separation of photogenerated electron–hole pairs at the heterojunction interface between the two materials were the key factors involved in the enhancement of the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Hierarchically structured covellite copper sulfide (CuS) microflowers composed of nanosheets have been successfully fabricated via a one-pot sonochemical process, using copper sulfate and thiourea aqueous solution as precursors in the presence of citric acid, without any prefabricated template. Large-scaled architectures are homogeneous and quite separately displaced and assembled by pure hexagonal single-crystalline CuS nanosheets, having thickness within 20 nm. The as obtained hierarchical CuS structures possess rather high surface area and unique double pore size distributions measured from N2 adsorption isotherms. Moreover, a possible growth mechanism for the CuS hierarchical architectures is proposed on the basis of temporal evolution controlled experiments. Most importantly, these hierarchically structured CuS catalysts showed highly efficient and versatile photo-catalytic activities as well as excellent recyclability in degrading highly concentrated dye aqueous solutions of methylene blue (MB), rhodamine B (RhB) and their mixed solution (MB + RhB) with the help of hydrogen peroxide (H2O2) under natural light irradiation, suggesting a promising application in wastewater purification. [ABSTRACT FROM AUTHOR]

Controlled micro/mesopores interconnected structures of three-dimensional (3D) carbon with high specific surface areas (SSA) are successfully prepared by carbonization and activation of biomass (raw rice brans) through KOH. The highest SSA of 2475 m2 g-1 with optimized pore volume of 1.21 cm3 g-1 (40% for mesopores) is achieved for KOH/RBC=4 mass ratio, than others. The as-prepared 3D porous carbon-based electrode materials for supercapacitors exhibit high specific capacitance specifically at large current densities of 10 A g-1 and 100 A g-1 i.e., 265 F g-1 and 182 F g-1 in 6 M KOH electrolyte, respectively. Moreover, a high power density ca. 1223 Wkg-1 (550 WL-1) and energy density 70 Wh kg-1 (32 Wh L-1) are achieved on the base of active material loading (~10 mg cm2) in the ionic liquid. The findings can open a new avenue to use abundant agricultural by-products as ideal materials with promising applications in high-performance energy-storage devices. [ABSTRACT FROM AUTHOR]

We firstly present a simple thermochemical method to fabricate high-quality Bi2Se3 nanoplatelets with enhanced figure of merit using elemental bismuth and selenium powders as precursors. The crystal structure of as synthesized products is characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM) measurements. Morphological and chemical synthetic parameters are investigated through a series of experiments; thickness and composition of the platelets are well controlled in large scale production. Subsequently spark plasma sintering (SPS) is performed to fabricate n-type nanostructured bulk thermoelectric materials. Raman Spectroscopy of the two selected samples with approximately of 50 and 100 nm thicknesses shows three vibrational modes. The lower thickness sample exhibits the maximum red shift of about 2.17 cm-1 and maximum broadening of about 10 cm-1 by in-plane vibrational mode E²g. The enhanced value of figure of merit ~0.41 is obtained for pure phase bismuth selenide to the best of our knowledge. We observe metallic conduction behavior while semiconducting behavior for nanostructured bismuth selenide is reported elsewhere which could be due to different synthetic techniques adopted. These results clearly suggest that our adopted synthetic technique has profound effect on the electronic and thermoelectric transport properties of this material. [ABSTRACT FROM AUTHOR]

We have developed a facile, scaled up, efficient and morphology-based novel WO3–g-C3N4 photocatalyst with different mass ratios of WO3 and g-C3N4. It was used for the photodegradation of rhodamine B (RhB) under visible light irradiation and it showed excellent enhanced photocatalytic efficiency as compared to pure g-C3N4 and WO3. The apparent performance of the composite/hybrid was 3.65 times greater than pure WO3 and 3.72 times greater than pure g-C3N4 respectively, and it was also found to be much higher than the previously reported ones. Furthermore, the optical properties of composite samples were evaluated. The bandgap of composite samples lies in the range of 2.3–2.5 eV, which was favourable for photodegradation. The possible mechanism for enhanced catalytic efficiency of the WO3–g-C3N4 photocatalyst is discussed in detail. It was found that the enhanced performance is due to the synergistic effect between the WO3 and g-C3N4 interface, improved optical absorption in the visible region and suitable band positions of WO3–g-C3N4 composites. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO 2 ) ultralong nanobelts were fabricated on silicon substrate by metal catalyzed Chemical Vapor Deposition (CVD) approach. An optical bandgap of 3.66 eV was calculated by optical absorbance data. Three Raman active modes peaks were observed at 474.4, 633 and 774.4 cm −1 . Room temperature photoluminescence (PL) exhibited an orange emission at 600 nm. A vapor–liquid–solid (VLS) process based growth mechanism for the formation of SnO 2 nanobelts was proposed and discussed briefly. Electrical transport characteristics of nanobelts were studied in dark and under ultraviolet (UV) laser. The fabricated device exhibited high photo-response properties under UV light, indicating their potential application as photo-switches and UV detectors. [ABSTRACT FROM AUTHOR]

Well controlled nanosheets-based hierarchical microspheres (NSHMS) of pure covellite phase CuS were synthesized using a facile PVP assisted solvothermal process. The reaction conditions were optimized using various amounts of PVP to develop unique hierarchical structured hollow microspheres. CuS hollow structures have a bandgap of ~1.97 eV. These mesoporous structures exhibit excellent photocatalytic activity in degradation of organic dyes (Methylene Blue) under natural light in comparison to other structures of copper sulphide. These photocatalysts show extraordinary reusability with over 96.5% degradation of organic dye after 6th cycle. A "bottom-up" assembly was successfully developed to synthesize hollow microspheres with unique and well defined architectures at large scale, which offer a good opportunity to understand the fundamental significance of unusual and complex hierarchical structures for their potential applications. [ABSTRACT FROM AUTHOR]

Abstract: We present first study on ZnV2O4 glomerulus nano/microspheres synthesize by template free route to expose its hydrogen storage potential. Besides this the evolution of nano/microspheres has been investigated in detail. To reveal possible growth mechanism of these spheres, time-dependent experiments are performed. Reitveld analysis is taken into account for calculation of lattice parameters, crystallite size and strain. From our results, a correlation between lattice parameters and crystallite size is observed. The strain decreases with the increase in reaction time. Hydrogen storage measurement reveals potential of ZnV2O4 nanospheres as a prospective material for energy storage applications. These studies can open new avenue of research for hydrogen storage in spinel oxide materials. [Copyright &y& Elsevier]

For the first time, high quality SnSe nanowires were synthesized via chemical vapour deposition (CVD). The synthesized SnSe nanowires are single crystalline. The length of the nanowires is in tens of microns with an average diameter of about 30-40 nm. Further, the optical and electrical properties reveal the potential of SnSe nanowires for photovoltaic and optical devices. These studies will enable significant advancements of the next generation photodetection and solar cell applications. [ABSTRACT FROM AUTHOR]

An easy, scalable and environmentally benign chemical method has been developed to synthesize micro strings of graphitic-C3N4 (msg-C3N4) through pre-treatment of melamine with HNO3 in alkaline solvent at low temperature. This methodology results in a unique string type morphology of msg-C3N4 with higher surface area. These msg-C3N4 micro strings were used as a photocatalyst under visible light for photodegradation of rhodamine B, methyl blue and methyl orange. The msg-C3N4 shows enhanced photodegradation efficiency due to its high surface area and favourable bandgap. The first order rate constant for msg-C3N4 was measured which confirms the higher performance of msg-C3N4 in comparison to other reported materials such as g-C3N4, Fe2O3/g-C3N4 and TiO2 nanotubes. Thus, the method developed here is favourable for the synthesis of materials with higher surface area and unique morphology, which are favourable for high photodegradation activity. [ABSTRACT FROM AUTHOR]

We report the synthesis of ZnV2O4 spinel oxide novel nanosheets via a template free route to explore its potential hydrogen storage properties for the first time. 2D layered nanostructures are excellent candidates for storage applications. This attracted our interest to synthesize novel spinel oxide nanosheets (NSNs) of ZnV2O4. The maximum value for hydrogen absorption in ZnV2O4 nanosheets at 473 K is 1.36 wt.% and 1.74 wt.% at 573 K, respectively. Our hydrogen storage measurements along ZnV2O4 reveal its superiority over previous reports on hydrogen absorption values concerning oxides, nitrides and chalcogenides. To understand the rate-limiting mechanism, various kinetics models are applied. The calculations show that kinetics is governed by 3D growth with constant interface velocity. The measurements point to ZnV2O4 spinel oxide as a promising hydrogen storage material. PL measurements demonstrate the potential for violet/blue optoelectronic devices. [ABSTRACT FROM AUTHOR]

Fabrication of SnO2nanobelts has been carried out by employing vapour liquid solid (VLS) and vapour solid (VS) mechanism. Nanobelts obtained by VLS mechanism were fabricated at relatively low temperature using Fe powders as a catalyst by means of chemical vapour deposition (CVD) technique. Direct thermal evaporation of SnO2nanobelts was carried out at 1350°C in the atmosphere of Argon gas via VS mechanism. In both cases, ramp rate was adjusted to 10°C/min. The structural, compositional and morphological characterisations of synthesised SnO2nanobelts were conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X‑ray spectroscopy (EDS). Magnetic behaviour of the nanobelts was studied by vibrating sample magnetometer (VSM). Cathodoluminescence (CL) spectra were studied using Renishaw Raman spectroscopy system. The growth of nanobelts is found to be homogeneous and dense. The nanobelts formed by VLS mechanism show ferromagnetic behaviour along with some other exciting results whereas the nanobelts formed by VS mechanism show a diamagnetic behaviour. The observed room temperature ferromagnetism in SnO2nanobelts is superior to other oxides. [ABSTRACT FROM PUBLISHER]

Abstract: The electronic, elastic, acoustic and optical properties of cubic phases TiO2 fluorite and pyrite are investigated using the first principles calculations. We have employed five different exchange–correlation functions within the local density and generalized gradient approximations using the ultrasoft plane wave pseudopotential method. The calculated band structures of cubic-TiO2 elucidate that the TiO2 fluorite and pyrite are direct and indirect semiconductors in contrast to the previous findings. From our studied properties such as bulk and shear moduli, elastic constants C44 and Debye temperature for TiO2 fluorite and pyrite, we infer that both the cubic phases are not superhard materials and the pyrite phase is harder than fluorite. The longitudinal and transversal acoustic wave speeds for both phases in the directions [100], [110] and [111] are determined using the pre-calculated elastic constants. In addition, we also calculate the optical properties such as dielectric function, absorption spectrum, refractive index and energy loss function using the pre-optimized structure. On the observation of optical properties TiO2 fluorite phase turn out to be more photocatalytic than pyrite. [Copyright &y& Elsevier]

Abstract: In this work we propose a novel idea of using thermoelectric material in lithium ion batteries. The reason behind this idea is to improve the efficiency of batteries especially when heat dissipation and exothermic reaction of cathode and anode with the electrolyte at higher temperatures restricts their continuous operation due to thermal runaway. In order to execute this idea we develop a new synthetic technique for fabrication of Bi2Se3 (thermoelectric material) and also compare it''s efficiency by preparing this material by existing synthetic technique. Charge/discharge comparison of both the samples indicate that the synthesis technique has a profound effect on electrochemical performance. Bismuth selenide (Bi2Se3) is intentionally selected for this purpose. Bi2Se3 rectangular nanosheets (BRNS) with thicknesses of 200–500 nm are synthesized by a simple thermochemical method in which we use bismuth and selenium powders as precursors. Self assembled nanosheets (SANS) in spherical shape are prepared by conventional hydrothermal technique. Charge discharge experiments show that BRNS synthesized with this technique have reasonable performance as compared to nanosheets synthesized by conventional hydrothermal technique. It shows that first discharge capacity is up to 725.6 mAh g−1 for BRNS and 419.6 mAh g−1 for SANS. [Copyright &y& Elsevier]

Abstract: Here we report the synthesis of highly pure single crystalline tin selenide (SnSe) nanospheres by pretreatment of precursors with aqueous ammonia. In this work we have demonstrated that aqueous ammonia not only controls the preferred growth orientation but also controls the morphology of SnSe. Chemical vapor deposition technique was used for the growth of SnSe nanostructures. The optical properties were studied using UV–vis–NIR spectroscopy and Photoluminescence (PL) spectrum. [Copyright &y& Elsevier]

Abstract: The ultrasoft pseudopotential technique is used to explore the elastic, electronic and optical properties of cotunnite TiO2 using LDA and GGA proposed by Perdew Wang (PW91), Perdew–Burke–Ernzerhof (PBE) functional as defined by Wu and Cohen (PBEWC) and PBE functional for solids (PBESOL). The calculated elastic constants bulk modulus, shear modulus and Young’s modulus are in agreement with the previous theoretical reports. From our investigated shear anisotropy factors (A1, A2, and A3), we infer that cotunnite TiO2 is strong anisotropy in case of A1 and A2 and less anisotropy in case of A3. The value of mean sound speed and Debye temperature are calculated using the obtained values of elastic moduli. The calculated structural parameters are in accord with the reported experiment and theoretical results. Our obtained values of direct bandgaps show an improvement over the other previous theoretical reports. The values of the dielectric constant (ε 1(ω)) of cotunnite TiO2 calculated within LDA and GGA approximations are 7.655 (LDA (CA-PZ)), 7.578 (GGA (PW91)), 7.685 (GGA (WC)) and 7.655 (GGA (PBESOL)), which are slightly higher than the experimental values of rutile (6.69) and anatase (6.55) polymorphs. The obtained values of the refractive index are consistent with rutile TiO2 and higher than anatase phase. The investigated imaginary part of dielectric constant and absorption spectrum reflect that the cotunnite TiO2 is a weak photocatalytic material as compared to anatase and similar to rutile phases. [Copyright &y& Elsevier]

This study investigates the photocatalytic degradation of nitrogen oxides over graphitic carbon nitride (g-C 3 N 4) based photocatalysts. The synthesis procedure of g-C 3 N 4 consists of two-step: in the first step, the synthesis of g-C 3 N 4 is carried out through a microwave heating method, whereas in the second step the as-synthesized product is annealed. The characterization was carried out by XRD (X-ray Diffraction), FESEM (Field Emission Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), BET (Brunauer-Emmet-Teller), and XPS (X-ray Photoelectron Spectroscopy). Photocatalytic activities for the degradation of NO x (Nitrogen Oxides) are compared with commercial TiO 2 and g-C 3 N 4 , to investigate the structural and physio-chemical features of prepared samples and their correlation with the catalytic activity. The results show that g-C 3 N 4 nanosheets have better activity and stability as compared to TiO 2. The deposition effect of 1 wt% Pt to the g-C 3 N 4 nanosheets is also observed which puts a negative effect on the degradation results. [Display omitted] • The material was synthesized by heating up the suspension at 110°C for 30 mins in microwave oven MAS-II plus at 300W. • It is observed through surface analysis the structure of g-C 3 N 4 nanosheets is porous with an estimated pore size of 20 nm. • In XPS analysis the peak at 399.6 eV shows most of the nitrogen in g-C 3 N 4 contributes to the C-N-C groups. • g-C 3 N 4 nanosheets shows better performance as compared to TiO 2 with 9.5% NO conversion and 0.33% photonic efficiency [ξ]. [ABSTRACT FROM AUTHOR]

To explore the effect of morphology on catalytic properties of graphitic carbon nitride (GCN), we have studied oxygen reduction reaction (ORR) performance of two different morphologies of GCN in alkaline media. Among both, tubular GCN react with dissolved oxygen in the ORR with an onset potential close to commercial Pt/C. Furthermore, the higher stability and excellent methanol tolerance of tubular GCN compared to Pt/C emphasizes its suitability for fuel cells. [ABSTRACT FROM AUTHOR]