Fabrication of graphene-based electrode in less than a minute through hybrid microwave annealing

Highly efficient and stable MoS 2 nanocrystals on graphene sheets (MoS 2 /GR) are synthesized via a hybrid microwave annealing process. Through only 45 second-irradiation using a household microwave oven equipped with a graphite susceptor, crystallization of MoS 2 and thermal reduction of graphene oxide into graphene are achieved, indicating that our synthetic method is ultrafast and energy-economic. Graphene plays a crucial role as an excellent microwave absorber as well as an ideal support material that mediates the growth of MoS 2 nanocrystals. The formed MoS 2 /GR electrocatalyst exhibits high activity of hydrogen evolution reaction with small onset overpotential of 0.1 V and Tafel slope of 50mV per decade together with an excellent stability in acid media. Thus our hybrid microwave annealing could be an efficient generic method to fabricate various graphene-based hybrid electric materials for broad applications.open2

Microwave synthesis of single-crystalline perovskite BiFeO3 nanocubes for photoelectrode and photocatalytic applications

A simple microwave synthesis procedure has been developed for the single-crystalline perovskite nanocubes composed of bismuth ferrite (BiFeO(3)). Typical nanocubes had sizes ranging from 50 to 200 nm. The single-crystalline nature of nanocubes was confirmed by high resolution transmission electron microscopy and selected area electron diffraction pattern. X-ray diffraction pattern showed the rhombohedral phase with R3c space group. The material showed photoinduced water oxidation activity in both photoelectrochemical and photocatalytic modes. It could become a useful material for photoelectrode and photocatalytic applications. (C) 2008 American Institute of Physicsclose878

Photoelectrochemical, impedance and optical data for self Sn-diffusion doped Fe2O3 photoanodes fabricated at high temperature by one and two-step annealing methods

The optical, morphological and photoelectrochemical (PEC) properties of transition metal oxide semiconductors are important to understand their influence on water oxidation performance. Herein, we provide experimental evidences for a better understanding of the factors that dictate the interactions of Sn-diffusion doping on the PEC properties of Fe2O3 photoanodes fabricated at high temperature by one- and two-step annealing methods. The synthesis, characterization methods and other experimental details are provided. Limited previous information on the PEC and electrochemical impedance spectroscopic studies has been published. This data article contains Supplementary data, figures and methods related to the research article by Shinde et al. (2015) [1]. Here, we provide a further set of the obtained experimental data results. ?? 2015 The Authors.close

Cottonseed Oilcake Extract Mediated Green Synthesis of Silver Nanoparticles and Its Antibacterial and Cytotoxic Activity

Agroindustrial byproduct mediated green synthesis of silver nanoparticles was carried out using cottonseed oilcake (CSOC) extract. The aqueous silver nitrate formed stable silver nanoparticles with CSOC extract as a reducing agent for Ag+ to Ag0. The synthesized nanoparticles were characterized using energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) techniques. The synthesized silver nanoparticles (AgNPs) (4 mM) significantly inhibited the growth of phytopathogens, Pseudomonas syringae pv. actinidiae and Ralstonia solanacearum. Further, cytotoxicity of AgNPs was evaluated using rat splenocyte cells. The splenocyte viability was decreased according to the increasing concentration of AgNPs and 90% of cell death was observed at 100 μg/mL

Indium induced band gap tailoring in AgGa(1-x)In(x)S(2) chalcopyrite structure for visible light photocatalysis

Indium was substituted at gallium site in chalcopyrite AgGaS(2) structure by using a simple solid solution method. The spectroscopic analysis using extended x-ray absorption fine structure and x-ray photoelectron spectroscopy confirmed the indium substitution in AgGaS(2) lattice. The band gap energy of AgGa(1-x)In(x)S(2) (x=0 - 1) estimated from the onset of absorption edge was found to be reduced from 2.67 eV (x=0 ) to 1.9 eV (x=1 ) by indium substitution. The theoretical and experimental studies showed that the indium s orbitals in AgGa(1-x)In(x)S(2) tailored the band gap energy, thereby modified the photocatalytic activity of the AgGa(1-x)In(x)S(2). (c) 2008 American Institute of Physicsclose217

Band gap tuning of lead-substituted BaSnO3 for visible light photocatalysis

The Pb substitution effect was investigated experimentally and theoretically on the crystal structure of BaSnO3 and on the photo-oxidation activity of H2O. The chemically doped Pb in BaSnO3 induced a concentration-dependent redshift of the experimental band gap (BG). The BaPb0.8Sn0.2O3 system produced 32 mu mol/h of O-2 under lambda >= 420 nm photons, but no O-2 for BaSnO3. The DFT calculations of BaPbxSn1-xO3 (x=0,0.5,1) by using generalized approximation, implying the BG alteration and the photocatalytic activity of BaPbxSn1-xO3, are due to the induced Pb 6s orbital in the BG of BaSnO3. Thus Pb modified the insulating nature of BaSnO3 to semiconducting and semimetallic. (c) 2007 American Institute of Physicsclose343

Is Myocardial Infarction in Patients without Significant Stenosis on a Coronary Angiogram as Benign as Believed?

The present study aimed to investigate the clinical characteristics and 1-year outcomes of acute myocardial infarction (AMI) patients without significant stenosis on a coronary angiogram comparison with the clinical characteristics and outcomes of patients with significant coronary artery stenosis. A total of 1,220 patients with AMI were retrospectively classified into Group I (≥50% diameter stenosis, n=1,120) and Group II (<50%, n=100). Group II was further divided into two subgroups according to the underlying etiology: cryptogenic (Group II-a, n=54) and those with possible causative factors (Group II-b, n=46). Patients in Group II were younger, were more likely to be women, and were less likely to smoke and to have diabetes mellitus than were patients in Group I. The levels of cardiac enzymes, LDL-cholesterol levels, and the apo-B/A1 ratio were lower in Group II. However, 1-month and 12-month rates of major adverse cardiac events (MACE) were not significantly different between the two groups. The Group II-b subgroup comprised 29 patients with vasospasm, 11 with myocardial bridge, and 6 with spontaneous thrombolysis. Left ventricular ejection fraction and creatinine clearance were lower and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) were higher in Group II-a than in Group II-b. However, outcomes including MACE and mortality at 12 months were not significantly different between the two subgroups. The 1-year outcomes of patients in Group II were similar to those of patients in Group I. The clinical outcomes in Group II-a were also similar to those of Group II-b, although the former group showed higher levels of NT-proBNP and hs-CRP

Heterojunction semiconductors: A strategy to develop efficient photocatalytic materials for visible light water splitting

Heterojunction semiconductors are discussed as a strategy to develop efficient visible light photocatalysts for water splitting. The concept has been demonstrated in photovoltaic cells and optoelectronic devices, for which junction-type semiconductors show greatly enhanced efficiency compared to the devices consisting of a single semiconductor. We applied this proven concept to fabricate photocatalysts of inorganic semiconductors. Thus heterojunction structures of Shottky junctions, p-n junctions (or p-n diode), p-n junctions with Ohmic layer, and bulk heterojunctions were fabricated and their photoactivity was tested for reduction or oxidation of water under visible light. The formation of heterojunctions results in the efficient separation of electron-hole pairs to minimize the energy-wasteful electron-hole recombination, which leads to the high photocatalytic activity. As the complexity and sophistication of the photocatalyst fabrication increased, the photoactivity also increased. Modern nanomaterial synthetic techniques were employed to bring into reality the highly engineered material configurations. (C) 2011 Elsevier B. V. All rights reservedclose494

Heterojunction photocatalyst TiO2/AgGaS2 for hydrogen production from water under visible light

A heterojunction photocatalyst TiO2/AgGaS2 consisting of bulky AgGaS2 with high crystallinity decorated with nanosized TiO2 particles was successfully fabricated by solid state reaction and sol-gel synthesis. TiO2 itself was inactive under visible light, but its combination with AgGaS2 improved greatly the rate of hydrogen production of AgGaS2 from water containing Na2S/Na2SO3 as sacrificial reagents under visible light irradiation. The fabrication method of the heterojunction photocatalysts was critical for their performance. This configuration of photocatalyst results in an efficient charge separation at the interface, followed by fast diffusion of photoelectrons generated in AgGaS2 towards surrounding TiO2 leading to high photocatalytic activity of hydrogen production. (c) 2009 Elsevier B.V. All rights reservedclose161