Aluminum nanotubes as an efficient catalyst for hydrogen production via thermochemical water splitting: a reactive molecular dynamics simulation.

Water splitting is the process of using energy to break down water molecules into hydrogen and oxygen. The use of an aluminum catalyst in the thermochemical process can help to increase the efficiency and rate of the reaction. Furthermore, aluminum is a relatively inexpensive material that can be easily produced, making it an appealing option for use in large-scale water-splitting operations. We investigated the reaction mechanism between aluminum nanotubes and water at various temperatures using reactive molecular dynamic simulations. We found that an aluminum catalyst makes it possible to split water at temperatures higher than T > 600 K. It was also observed that the yield of H2 evolution is dependent on the diameter of the Al nanotube and decreases with increasing size. During the process of splitting water, the inner surfaces of the aluminum nanotubes are seen to be severely eroded, as shown by changes in the aspect ratio and solvent-accessible surface area. In order to compare the H2 evolution efficiency of water with other solvents, we also split a variety of solvents, including methanol, ethanol, and formic acid. We presume that our study will give researchers enough knowledge to create hydrogen through thermochemical process in the presence of an aluminum catalyst by dissociating water and other solvent molecules.

de novo transcriptome profile of two earthworms Lampito mauritii and Drawida calebi during regeneration.

Earthworms have remarkable ability to regenerate its tail and head region. However the list of genes expressed in this regeneration process has been less explored baring a few species. The current study involves the de novo transcriptome sequencing of intact tail and regenerating tail (15 day post amputation) of earthworms belonging to two different genera Lampito mauritii (Kinberg, 1867) and Drawida calebi (Gates, 1945). This study contains one de-novo and one reference based transcriptome analysis each from one genus of two earthworm genera. From a total of 119.92 million (150 × 2) reads, 112.95 million high quality adapter free reads were utilized in analysis. Assembly of high-quality reads was performed separately for Lampito mauritii (LM sample) and Drawida calebi (DC sample) that resulted in 66368 and 1,61,289 transcripts respectively. About 25.21% of transcripts were functionally annotated for DC sample and 38.27% for LM samples against Annelida sequences. A total of 239 genes were expressed exclusively in regenerated tissue compared to intact sample in DC whereas about 241 genes were exclusively expressed in regenerated tissue of LM compared to its intact sample. Majority of genes in Drawida and Lampito were dedicated to immune response, maintenance of cytoskeleton, resisting oxidative stress and promoting neuronal regeneration for cell-cell communication during tail regeneration.

Conservation of gene architecture and domains amidst sequence divergence in the hsrω lncRNA gene across the Drosophila genus: an in silico analysis.

The developmentally active and cell-stress responsive hsrω locus in Drosophila melanogaster carries two exons, one omega intron, one short translatable open reading frame (ORFω), long stretch of unique tandem repeats and an overlapping mir-4951 near its 30' end. It produces multiple long noncoding RNAs (lncRNAs) using two transcription start and four termination sites. Earlier cytogenetic studies revealed functional conservation of hsrω in several Drosophila species. However, sequence analysis in three species showed poor conservation for ORFω, tandem repeat and other regions while the 16 nt at 50 and 60 nt at 30 splice junctions of the omega intron, respectively, were found to be ultra-conserved. The present bioinformatic study using the splice-junction landmarks in D. melanogaster hsrω identified orthologues in publicly available 34 Drosophila species genomes. Each orthologue carries a short ORFω, ultra-conserved splice junctions of omega intron, repeat region, conserved 30'end located at mir-4951, and syntenic neighbours. Multiple copies of conserved nonamer motifs are seen in the tandem repeat region, despite a high variability in the repeat sequences. Intriguingly, only the omega intron sequences in different species show evolutionary relationships matching the general phylogenetic history in the genus. Search in other known insect genomes did not reveal sequence homology although a locus with similar functional properties is suggested in Chironomus and Ceratitis genera. Amidst the high sequence divergence, the conserved organization of exons, ORFω and omega intron in this gene's proximal part and tandem repeats in distal part across the Drosophila genus is remarkable and possibly reflects functional importance of higher order structure of hsrω lncRNAs and the small omega peptide.

Modulating the electronic structure of lanthanum manganite by ruthenium doping for enhanced photocatalytic water oxidation.

To the best of our knowledge this is the first report in which ruthenium doped polycrystalline lanthanum manganite, LaMn1-xRuxO3 (x = 0.0-0.4), having high efficacy for oxygen production from water without the use of any sacrificial reagent or co-catalyst and as an efficient photocatalyst for dye degradation is reported. Ruthenium doping alters the crystal structure of the parent LaMnO3 (LMO) due to the induced chemical pressure of the larger Ru4+ ion, which facilitates a bond angle of 180° in the Mn3+-O-Mn4+ plane resulting in the easy extraction of a photo-generated charge carrier population leading to enhanced photocatalytic activity. Rietveld refinements reveal that the parent compound LMO crystallizes in the rhombohedral phase, while upon an increase in the doping concentration of ruthenium, the phase of the compounds changes from the rhombohedral to the cubic phase. The percentage contribution of each phase has been estimated using the sixth-order polynomial and pseudo-Voigt function. Typically, all the compositions, LaMn1-xRuxO3 (x = 0.0-0.4), were prepared by a conventional solid state route and studied for their photocatalytic activity. The synthesized compounds were investigated by powder X-ray diffraction (PXRD), UV-visible diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. The structure-property correlation of the compound is presented based on Rietveld refinement combined with the experimental data. The as-prepared compounds show efficient photocatalytic oxygen gas production from water without the use of any co-catalyst or sacrificial reagents. Among the five compositions, LaMn0.7Ru0.3O3 shows the highest O2 production efficiency (4.73 mmol g-1 h-1) with an apparent quantum yield (AQY) of 7.43%. These ruthenium doped compositions also exhibit superior dye degradation properties, studied by taking the industrial dye methyl orange (MO) as the model compound.

Efficient anti-corrosive coating of cold-rolled steel in a seawater environment using an oil-based graphene oxide ink.

We report the production of an efficient anti-corrosive coating of cold-rolled (CR) steel in a seawater environment (∼3.5 wt% NaCl aqueous solution) using an oil-based graphene oxide ink. The graphene oxide was produced by heating Aeschynomene aspera plant as a carbon source at 1600 °C in an argon atmosphere. The ink was prepared by cup-milling the mixture of graphene oxide and sunflower oil for 10 min. The coating of ink on the CR steel was made using the dip-coating method, followed by curing at 350 °C for 10 min in air atmosphere. The results of the potentiodynamic polarization show that the corrosion rate of bare CR steel decreases nearly 10,000-fold by the ink coating. Furthermore, the salt spray test results show that the red rusting in the ink-coated CR steel is initiated after 100 h, in contrast to 24 h and 6 h in the case of oil-coated and bare CR steel, respectively. The significant decrease in the corrosion rate by the ink-coating is discussed based on the impermeability of graphene oxide to the corrosive ions.

Observation of large positive magneto-resistance in bubble decorated graphene oxide films derived from shellac biopolymer: a new carbon source and facile method for morphology-controlled properties.

We report a large positive magneto-resistance (MR) in bubble decorated graphene oxide films that are derived from shellac biopolymer as a carbon source. These films were produced on a quartz substrate by heating the biopolymer coated substrate at 900 °C in an argon atmosphere. The characterization data of the films using Raman, X-ray photoelectron spectroscopy, field emission scanning electron microscopy and transmission electron microscopy reveal that shellac can be used as a new carbon source to produce transparent bubble decorated graphene oxide films. The magneto-resistance results show a 130% change in the resistance of the films at 3 K under a perpendicular magnetic field of 15 T, and the value decreases exponentially up to 50 K. The observed MR properties of the bubble decorated graphene oxide films are explained using a weak anti-localization and quantum interference model in the low magnetic field region, while the Lorentz force accounts for the MR properties well in the high magnetic field region.

Pt-Pd alloy nanoparticle-decorated carbon nanotubes: a durable and methanol tolerant oxygen reduction electrocatalyst.

We describe the decoration of multiwalled carbon nanotubes (MCNTs) with Pt-Pd alloy nanoelectrocatalysts of three different compositions and their electrocatalytic performance toward the oxygen reduction reaction (ORR). The decoration of the MCNTs involves polymer-assisted impregnation of metal precursors PtCl(6)(2-) and PdCl(6)(2-) and the subsequent reduction of the impregnated precursors by a modified polyol route. The composition of the catalyst was controlled by tuning the molar ratio of the precursors during their impregnation. Electron probe microscopic analysis shows that the catalysts have compositions of Pt(46)Pd(54,) Pt(64)Pd(36) and Pt(28)Pd(72). The Pt(46)Pd(54) and Pt(64)Pd(36) catalysts have truncated octahedral and icosahedral shapes with a size ranging from 8 to 10 nm. On the other hand, the catalyst of Pt(28)Pd(72) composition has a spherical/quasispherical shape with a size distribution of 1-2 nm. The XPS measurement confirms the signature of metallic Pt and Pd. The Pt(46)Pd(54) catalyst has a pronounced electrocatalytic activity toward the ORR with a specific and mass activity of 378 µA cm(Pt-Pd)(-2) and 64 µA µg(Pt-Pd)(-1), respectively at 0.8 V. Moreover, the Pt(46)Pd(54) nanoelectrocatalyst is highly durable and it retains its initial catalytic activity even after 1000 extensive cycles. Interestingly, this catalyst has a very high tolerance toward methanol and it does not favor the oxidation of methanol in the potential window of 0.1-1.4 V. The electrocatalytic activity of the alloy electrocatalyst is compared with commercially available Pt black and MCNT-supported spherical Pt nanoparticles. The catalytic activity of the Pt(46)Pd(54) nanoelectrocatalyst is higher than the other catalysts. The Pt(46)Pd(54) catalyst outperforms the electrocatalytic activity of all other catalysts.

A rapid room temperature chemical route for the synthesis of graphene: metal-mediated reduction of graphene oxide.

A rapid and facile route for the synthesis of reduced graphene oxide sheets (rGOs) at room temperature by the chemical reduction of graphene oxide using Zn/acid in aqueous solution is demonstrated.

Stabilization of intrinsic defects at high temperatures in ZnO nanoparticles by Ag modification.

The stabilization of defects in ZnO at high temperatures has been investigated. The properties of unmodified and modified ZnO nanoparticles (NPs) with 2 at.% of Ag prepared by microwave assisted combustion method, have been systematically studied using X-ray diffraction (XRD), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and photocatalytic activity measurements. Though the XRD data shows a marginal shift in the ZnO peak position upon Ag addition, the amount of shift does not change with annealing temperatures. The PL data reveals that the defect mediated visible emission intensity of unmodified ZnO NPs increases with increase in the annealing temperature, whereas it remains almost unchanged in Ag-ZnO. This study clearly establishes that silver is an efficient stabilizer of intrinsic defects in ZnO at high temperatures. This is further supported by the core and valence band XPS spectra.

A facile approach for morphosynthesis of Pd nanoelectrocatalysts.

A facile approach has been developed for synthesis of highly-structured, anisotropic Pd nanostructures. The dendritic Pd nanostructures show superior performance toward oxidation of formic acid and methanol for fuel cell application.

Effect of Ru-Mn redox interactions on the hole carrier density in pulsed electron deposited La(1-x)Pb(x)Mn(0.8)Ru(0.2)O(3) (0.2≤x≤0.4) thin films.

Pulsed electron deposited thin films of Ru substituted La(1-x)Pb(x)Mn(0.8)Ru(0.2)O(3) (0.2≤x≤0.4) show an increase in the magneto-resistance ratio by ∼5-15% at the respective metal to insulator transition (T(MIT)) temperature when compared to the parent La(0.6)Pb(0.4)MnO(3) thin film. A systematic decrease in T(MIT) is observed from ∼310 to ∼260 K when the hole (Pb) concentration varies from 40 to 20% with constant 20% Ru substitution at the Mn site. The x-ray rocking curve and high-resolution transmission electron microscopy (HRTEM) images of the thin films suggest that Ru occupies the Mn site and shows epitaxial growth of the films on the LaAlO(3) (LAO) substrate. Transport and magneto-resistive properties show that Ru substitution maintains a considerable hole carrier density (due to Mn(4+):t(2g)(3)e(g)(0)/Ru(5+):t(2g)(3)e(g)(0)) even for La(0.8)Pb(0.2)Mn(0.8)Ru(0.2)O(3) (8282) composition, which influences the double exchange interactions.

Evidence for an anomalous redox ionic pair between Ru and Mn in SrRu0.5Mn0.5O3: an X-ray absorption spectroscopy approach.

X-ray absorption spectroscopy studies of the polycrystalline SrRu0.5Mn0.5O3 have been performed at Ru, Mn-L2,3 edges. The 2p-->t2g related peak at the Ru-L2 edge is more intense than the Ru-L3 edge and a shift of the 2p-->eg related peak by approximately 0.8 eV to higher energy than that of the Ru(IV) compound, SrRuO3 is observed. In combination with a crystal field multiplet calculation approach, a possible anomalous change in the spectral features is explained based on the existence of a redox ionic pair involving Ru(IV)/Ru(v)<-->Mn(III)/Mn(IV).