2,859 publications from this institution
Replacement of precious Pt with earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) holds great promise for clean energy devices, but the development of low-cost and durable HER catalysts with Pt-like activity is still a huge challenge. In this communication, we report on the development of self-standing ternary Fe<sub>x</sub>Co<sub>1-x</sub>P nanowire array on carbon cloth (Fe<sub>x</sub>Co<sub>1-x</sub>P/CC) as a Pt-free HER catalyst with activities being strongly related to Fe substitution ratio. Electrochemical tests show that Fe<sub>0.5</sub>Co<sub>0.5</sub>P/CC not only possesses Pt-like activity with the need of overpotential of only 37 mV to drive 10 mA cm<sup>-2</sup>, outperforming all non-noble-metal HER catalysts reported to date, but demonstrates superior long-term durability in 0.5 M H<sub>2</sub>SO<sub>4</sub>. Density functional theory calculations further reveal that Fe substitution of Co in CoP leads to more optimal free energy of hydrogen adsorption to the catalyst surface. This study offers us a promising flexible monolithic catalyst for practical applications.
The syntheses of cationic ruthenium(II) complexes [Ru(Me<sub>2</sub>-bpy)(PPh<sub>3</sub>)<sub>2</sub>RRʹ][PF<sub>6</sub>]<sub>x</sub> {Me<sub>2</sub>-bpy = 4,4ʹ-dimethyl-2,2ʹ-bipyridine, (<b>3</b>) R = Cl, Rʹ = N≡CMe, x = 1, (<b>4</b>) R = Cl, Rʹ = N≡CPh, x = 1, (<b>5</b>) R = Rʹ = N≡CMe, x = 2} and [Ru(Me<sub>2</sub>-bpy)(<i>κ</i><sup>2</sup>-dppf)RRʹ][PF<sub>6</sub>]<sub>x</sub> {dppf = 1,1ʹ-bis(diphenylphosphino)ferrocene, (<b>6</b>) R = Cl, Rʹ = N≡CMe, x = 1, (<b>7</b>) R = Cl, Rʹ = N≡CPh, x = 1, (<b>8</b>) R = Rʹ = N≡CMe, x = 2} are reported, together with their structural confirmation by NMR (<sup>31</sup>P, <sup>1</sup>H) and IR spectroscopy and elemental analysis, and, in the case of <i>trans</i>-[Ru(Me<sub>2</sub>-bpy)(PPh<sub>3</sub>)<sub>2</sub>(N≡CCH<sub>3</sub>)Cl][PF<sub>6</sub>] (<b>3</b>), by X-ray crystallography. Electronic absorption and emission spectra of the complexes reveal that all complexes except <b>4</b> and <b>6</b> are emissive in the range 370–400 nm with <b>8</b> exhibiting an emission in the blue. Cyclic voltammetry studies of <b>3–8</b> show reversible or quasi-reversible redox processes at <i>ca.</i> 1 V, assigned to the Ru(II/III) couple.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In this work, we report the facile, environmentally friendly, room-temperature (RT) synthesis of porous CuO nanosheets and their application as a photocatalyst to degrade an organic pollutant/food dye using NaBH<sub>4</sub> as the reducing agent in an aqueous medium. Ultrahigh-resolution field effect scanning electron microscopy images of CuO displayed a broken nanosheet-like (a length of ∼160 nm, a width of ∼65 nm) morphology, and the lattice strain was estimated to be ∼1.24 × 10<sup>-3</sup> using the Williamson-Hall analysis of X-ray diffraction plots. Owing to the strong quantum size confinement effect, CuO nanosheets resulted in an optical energy band gap of ∼1.92 eV, measured using Tauc plots of the ultraviolet-visible (UV-vis) spectrum, resulting in excellent photocatalytic efficiency. The RT synthesized CuO catalyst showed a high Brunauer-Emmet-Teller surface area of 30.88 ± 0.2313 m<sup>2</sup>/g (a correlation coefficient of 0.99972) with an average Barrett-Joyner-Halenda pore size of ∼20.385 nm. The obtained porous CuO nanosheets exhibited a high crystallinity of 73.5% with a crystallite size of ∼12 nm and was applied as an efficient photocatalyst for degradation of the organic pollutant/food dye, Allura Red AC (AR) dye, as monitored by UV-vis spectrophotometric analysis and evidenced by a color change from red to colorless. From UV-vis spectra, CuO nanosheets exhibited an efficient and ultrafast photocatalytic degradation efficiency of ∼96.99% for the AR dye in an aqueous medium within 6 min at RT. According to the Langmuir-Hinshelwood model, photodegradation reaction kinetics followed a pseudo-first-order reaction with a rate constant of <i>k</i> = 0.524 min<sup>-1</sup> and a half-life (<i>t</i> <sub>1/2</sub>) of 2.5 min for AR dye degradation in the aqueous medium. The CuO nanosheets showed an outstanding recycling ability for AR degradation and would be highly favorable and an efficient catalyst due to the synergistic effect of high adsorption capability and photodegradation of the food dye.
The title mol-ecule, C(11)H(15)N(3)O(2)S, features a five-membered ring which is twisted about the middle CH(2)-CH(2) bond. The benzene ring is inclined with respect to the imine residue [C-N-N-C torsion angle = 165.4 (2)°]. Supra-molecular layers in the bc plane are formed by hydrogen bonds between the amine H atoms and sulfonamide O and imine N atoms, as well as by a weak hydrazine H-atom inter-molecular inter-action with the second sulfonamide O atom.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The title compound, 1-(2,5-dimethyl-3-thienyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (3) was synthesized in high yield by an aldol condensation reaction of 3-acetyl-2,5-dimethythiophene and 2,4,5-trimethoxybenzaldehyde in methanolic NaOH at room temperature. Its structure was fully characterized by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral data.
This work presents the fabrication and temperature sensing properties of the carbon nanotubes-silicon (CNT-Si) nanocomposites based sensors. The multi-walled carbon nanotubes used for the fabrication of sensors have diameter in the range of 10-30, while the silicon powder (1.99 μm) is obtained by the milling of p-Si crystal wafers containing impurity (boron) concentration of 1016 cm–3. For the synthesis of nanocomposites the silicone adhesive (Hero Gum) and organic polymer (GMSA) are used as an binding materials. Four different types of composites are prepared for the fabrication of sensors. Film deposition is carried out by using drop casting and doctor blade technology. In all the sensors entire thickness of composite film is equal to 100 μm. The temperature sensitivity is found in the range of 0.53 %/ °C to -0.74 %/°C. Depending on composition, ratio of components and kind of adhesive materials the initial resistance values of the sensors are in the range of 260 Ω to 34 kΩ. The simulation of experimental results is carried out by using exponential function and the simulated results are in good agreement with the experimental results.
