Abstract Development of earth‐abundant bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is highly desirable but still remains a great challenge. In this Communication, we demonstrate that a Ni‐P alloy nanoparticle film electrodeposited on Ni foam (Ni‐P/NF) acts as an efficient bifunctional water‐splitting electrocatalyst with strong durability in alkaline media. This electrode needs overpotentials of 80 and 309 mV to drive 10 mA cm −2 for HER and OER, respectively, in 1.0 m KOH, and its two‐electrode water electrolyzer requires voltage of 1.67 V to reach 10 mA cm −2 .
The electronic absorption spectra, ground-state geometries and electronic structures of symmetric and asymmetric squaraine dyes (SQD1-SQD4) were investigated using density functional theory (DFT) and time-dependent (TD-DFT) density functional theory at the B3LYP/6-311++G** level. The calculated ground-state geometries reveal pronounced conjugation in these dyes. Long-range corrected time dependent density functionals Perdew, Burke and Ernzerhof (PBE, PBE1PBE (PBE0)), and the exchange functional of Tao, Perdew, Staroverov, and Scuseria (TPSSh) with 6-311++G** basis set were employed to examine optical absorption properties. In an extensive comparison between the optical data and DFT benchmark calculations, the BEP functional with 6-311++G** basis set was found to be the most appropriate in describing the electronic absorption spectra. The calculated energy values of lowest unoccupied molecular orbitals (LUMO) were 3.41, 3.19, 3.38 and 3.23 eV for SQD1, SQD2, SQD3, and SQD4, respectively. These values lie above the LUMO energy (-4.26 eV) of the conduction band of TiO₂ nanoparticles indicating possible electron injection from the excited dyes to the conduction band of the TiO₂ in dye-sensitized solar cells (DSSCs). Also, aromaticity computation for these dyes are in good agreement with the data obtained optically and geometrically with SQD4 as the highest aromatic structure. Based on the optimized molecular geometries, relative positions of the frontier orbitals, and the absorption maxima, we propose that these dyes are suitable components of photovoltaic DSSC devices.
The title compound, 5-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)methylene]-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione, has been synthesized by condensation of 1,3-diethyl-2-thiobarbituric acid and 3,5-dimethyl-1-phenylpyrazole-4-carbaldehyde in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and EI-MS spectral analysis.
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.
Abstract Magnesium titanate (MgTiO 3 ) has been successfully synthesized via the sonochemical method by using TiO 2 (P25) and Magnesium nitrate (MgNO 3 ) 2 .6H 2 O as precursors without any additional phases such as MgTi 2 O 5 and Mg 2 TiO 4 . The synthesized nanoparticles were well characterized by optical methods using UV‐Vis diffuse reflectance spectroscopy (DRS) and Photoluminescence spectroscopy (PL). The morphology of MgTiO 3 nanoparticles is irregular in shape with serious agglomerations were confirmed through SEM analysis. XRD confirms crystal structure and phase purity of MgTiO 3 nanoparticles calcined at 700 °C for 2 hours. The calculated band gap energy of MgTiO 3 nanoparticles has been found to be 3.05 eV. Using the prepared MgTiO 3 nanoparticles, the photocatalytic activities were evaluated by following the degradation of Congo red dye under visible light. Moreover, the influence of various scavengers on the photocatalytic reaction were studied.
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.
Three carbazole chromophores featuring dicyano, cyano, ethyl acetate and dimethyl acetate groups as an acceptor moiety with a <TEX>${\pi}$</TEX>-conjugated spacer and <TEX>$N$</TEX>-methyl dibenzo[<TEX>$b$</TEX>]pyrole as donor were synthesized by Knovenagel condensation and characterized by IR, <TEX>$^1HNMR$</TEX>, <TEX>$^{13}CNMR$</TEX>, UV-vis, fluorescence spectroscopy, electrochemistry and theoretical B3LYP/6-<TEX>$311G^*$</TEX> level whilst NLO properties and spectroscopic quantities were calculated. Calculations showed remarkable trend with HOMO located on the donor moiety and LUMO on the acceptors dicyano methylene, cyano, ethyl acetate methylene and dimethyl acetate methylene. In agreement with the calculations, solvatochromic, behavior intramolecular charge transfer band was observed in the visible region.
The title compound, (2E)-3-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)-1-(2,5-dimethyl-3-furanyl)prop-2-en-1-one (3) was synthesized in high yield by an aldol condensation between 3-acetyl-2,5-dimethylfuran and 3,5-dimethyl-1-phenylpyrazole-4-carboxaldehyde in ethanolic NaOH at room temperature. Its structure was fully characterized by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.
