Carbon-Coated ZnS-FeS2 Heterostructure as an Anode Material for Lithium-Ion Battery Applications

The construction of carbon-coated heterostructures of bimetallic sulfide is an effective technique to improve the electrochemical activity of anode materials in lithium-ion batteries. In this work, the carbon-coated heterostructured ZnS-FeS₂ is prepared by a two-step hydrothermal method. The crystallinity and nature of carbon-coating are confirmed by the investigation of XRD and Raman spectroscopy techniques. The nanoparticle morphology of ZnS and plate-like morphology of FeS₂ is established by TEM images. The chemical composition of heterostructure ZnS-FeS₂@C is discovered by an XPS study. The CV results have disclosed the charge storage mechanism, which depends on the capacitive and diffusion process. The BET surface area (37.95 m²g⁻¹) and lower R_ct value (137 Ω) of ZnS-FeS₂@C are beneficial to attain higher lithium-ion storage performance. It delivered a discharge capacity of 821 mAh g⁻¹ in the 500th continuous cycle @ A g⁻¹, with a coulombic efficiency of around 100%, which is higher than the ZnS-FeS₂ heterostructure (512 mAh g⁻¹). The proposed strategy can improve the electrochemical performance and stability of lithium-ion batteries, and can be helpful in finding highly effective anode materials for energy storage devices.     

Room temperature ferromagnetism in Co doped ZnO within an optimal doping level of 5%

We report on the structural, micro-structural and magnetic properties of Zn_1?xCo_xO (0 ≤ x ≤ 0.1) system. Electron probe micro-structural analysis on 5% Co doped ZnO indicates the presence of segregated cobalt oxide which is also confirmed from the Co 2p core level X-ray photoelectron spectrum. The presence of oxygen defects in lower percentage of Co doped ZnO (≤5%) enhances the carrier mediated exchange interaction and thereby enhancing the room-temperature ferromagnetic behaviour. Higher doping percentage of cobalt (>5%) creates weak link between the grains and suppresses the carrier mediated exchange interaction. This is the reason why room temperature ferromagnetism is not observed in 7% and 10% Co doped ZnO.     

Anisotropic interface induced formation of Sb nanowires on GaSb(111)A substrates

The growth of Sb nanowires on GaSb(111)A substrates is studied by in?situ azimuthal scan reflection high-energy electron diffraction (ARHEED). Bulk and layer contributions can be distinguished in the ARHEED transmission pattern through the Sb nanowires. The three-dimensional structure of the growing Sb nanowires is identified by post-growth atomic force microscopy (AFM) and x-ray diffraction (XRD). The lattice match of the Sb crystal along the [Formula: see text] and the GaSb crystal along [Formula: see text] directions lead to a preferential orientation of the Sb nanowires. The Sb adsorption and desorption kinetics is studied by thermal desorption spectroscopy.     

Facile hydrothermal bio‐synthesis of cellulose acetate templated CuS nanorods like fibres: antibacterial,cytotoxicity effects and DNA cleavage properties against A549 lung cancer cells

In this research, the hydrothermal method was used for synthesising cellulose acetate (CA) templated nanorods like CuS fibres using vegetable extract (Brassica oleracea var. italica). These extracts act as a reducing agent in the presence of CA. Surprisingly, when the same reaction was carried out in the absence of CA and broccoli extract, structural morphology disappeared and was found as agglomerated. In the presence of cellulose templated extract mediated CuS has revealed as nanorods like fibres and was confirmed by field emission scanning electron microscope analysis. Their crystallinity property of CuS nanoparticles (NPs) and cellulose templated biosynthesised CuS NPs was analysed and compared using X‐ray diffraction technique. The biological activities of the obtained product were examined for antibacterial assessment against two bacterial strains that include two‐gram negative strains (E.Coli and S. aureus). The nanostructured product found to exhibit excellent antibacterial agent against all the strains. Biosynthesised nanostructure showed its efficacy against A549 lung cancer cells which might attribute to a larger surface to volume ratio of nanorods like fibres. The authors observation suggest that CuS nanorods like fibres can significantly reduce the cell growth with IC₅₀ value of 31.2 μg/ml.Inspec keywords: nanomedicine, copper compounds, X‐ray diffraction, nanorods, nanofabrication, antibacterial activity, DNA, toxicology, microorganisms, molecular biophysics, cancer, cellular biophysics, biomedical materials, nanoparticles, lung, field emission scanning electron microscopy, polymers, crystal growth from solutionOther keywords: A549 lung cancer cells, hydrothermal method, structural morphology, crystallinity property, CuS nanoparticles, two‐gram negative strains, CuS nanorods, cytotoxicity effects, DNA cleavage properties, cellulose acetate, Brassica oleracea var. italica, field emission scanning electron microscope, X‐ray diffraction, antibacterial agent, hydrothermal biosynthesis, CuS     

CsPbI3 nanorods as the interfacial layer for high-performance,all-solution-processed self-powered photodetectors

Heterojunction is regarded as a crucial step toward realizing high-performance devices,particularly,forming gradient energy band between heterojunctions benefits self-powered photodetectors.There-fore,in this paper,the synthesis of CsPbI3 nanorods(NRs)and its application as the interfacial layer in high-performance,all-solution-processed self-powered photodetectors are presented.For the bilayer photodetector ITO/ZnO(100 nm)/PbS-TBAI(150 nm)/Au,a responsivity of 3.6 A/W with a specific detec-tivity of 9.8×1012 Jones was obtained under 0.1 mW/cm2 white light illumination at zero bias(i.e.in self-powered mode).Meanwhile,the photocurrent was enhanced to an On/Off current ratio of 10s at zero bias with an open circuit voltage of 0.53 V for trilayer photodetector ITO/ZnO(100 nm)/PbS-TBAI(150 nm)/CsPbI3(250 nm)/Au,in which the CsPbI3 NRs layer works as the interfacial layer.As a result,a specific detectivity of 4.5×1013 Jones with a responsivity of 11.12 A/W was obtained under 0.1 mW/cm2 white light illumination,as well as the rising/decaying time of 0.57 s/0.41 s with excellent stability and reproducibility upto four weeks in air.The enhanced-performance is ascribed to the mis-match bandgap between PbS-TBAI/CsPbI3 interface,which can suppress the carrier recombination and provide efficient transport passages for charge carriers.Thus,it provides a feasible and efficient method for high-performance photodetectors.     

Chemical Composition,Amino Acid Content and Protein Quality of the Little-Known Legume Bauhinia purpurea L

Some nutritional and antinutritional characteristics and biological value of Bauhinia purpurea L seeds were studied. The mature seeds contained (g kg^-1 as is) 271·7 crude protein, 58·7 crude fibre, 124·5 crude fat, 29·3 ash and 515·3 carbohydrates. Potassium, phosphorus and iron occurred in higher concentrations when compared with commonly consumed legumes. The globulins and albumins together constituted major storage proteins (82% total protein). The essential amino acid profile of total seed proteins compared well with the FAO/WHO reference pattern except for a deficiency of sulphur-containing amino acids and tryptophan. When compared with the globulins, the albumins appeared to be a rich source of cystine, methionine, threonine, lysine and tryptophan. Seed lipids contained high levels of the unsaturated fatty acids, oleic and linoleic, which accounted for 62·6% of total fatty acids recovered. Both dry heating and autoclaving significantly reduced the antinutritional compounds. The in vitro protein digestibilities of raw, dry-heated and autoclaved seeds were 59·5, 72·3 and 78·7%, respectively. True digestibility and net protein utilisation were significantly higher in processed seed samples compared with raw seeds. Regarding utilisable protein, autoclaved samples exhibited relatively higher values than raw seeds. © 1997 SCI.     

Structural and optical properties of electron beam evaporated CdSe thin films

Thin films of cadmium selenide (CdSe) as a semiconductor is well suited for opto-electronic applications such as photo detection or solar energy conversion, due to its optical and electrical properties, as well as its good chemical and mechanical stability. In order to explore the possibility of using this in optoelectronics, a preliminary and thorough study of optical and structural properties of the host material is an important step. Based on the above view, the structural and optical properties of CdSe films have been studied thoroughly in the present work. The host material, CdSe film, has been prepared by the physical vapour deposition method of electron beam evaporation (PVD: EBE) technique under a pressure of 5 × 10⁻⁵ mbar. The structural properties have been studied by XRD technique. The hexagonal structure with a preferred orientation along the (0 0 2) direction of films has been confirmed by the X-ray diffraction analysis. The films have been analysed for optical band gap and absorbed a direct intrinsic band gap of 1·92 eV.     

Pyreno-chalcone dendrimers as an additive in the redox couple of dye-sensitized solar cells

Novel pyreno-chalcone dendrimers 1, 2, and 3 were synthesized and their ability to act as an additive in the redox couple (I⁻/I₃ ⁻) of dye-sensitized nanocrystalline TiO₂ solar cell has been tested. The redox couple doped with pyreno-chalcone dendrimer 3 gave a short circuit photocurrent density (J _sc) of 7.40 mA/cm², open circuit voltage (V _oc) of 820 mV, and a fill factor of 0.51, corresponding to an overall conversion efficiency (η) of 7.89% under 40 mW/cm² irradiation.