Reganbruun3812

It is considerably rearranged in the low pressure Pnma form. Experiments at 10 GPa showed an initial formation of fcc Na3NiH5 followed by the addition of the perovskite hydride NaNiH3, in which Ni(II) attains an octahedral environment by H atoms. NaNiH3 is recoverable at ambient pressures and represents the sole product of 12 GPa experiments. DFT calculations show that the decomposition of Na3NiH5 = NaNiH3 + 2 NaH is enthalpically favored at all pressures, suggesting that Na3NiH5 is metastable and its formation is kinetically favored. Ni-H bonding in metallic NaNiH3 is considered covalent, as in electron precise Na3NiH5, but delocalized in the polyanion [NiH3]-. Copyright © 2020 American Chemical Society.A Zn(II)-based metal-organic framework (MOF) compound and MnO2 were used to prepare ZnO x -MOF@MnO2 composites for selective Sr2+ removal in aqueous solutions. The ZnO x -MOF@MnO2 composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and Brunauer-Emmett-Teller surface area analysis. IACS-13909 The functional groups, morphologies, thermal stabilities, and specific surface areas of the composites were suitable for Sr2+ adsorption. A maximum adsorption capacity of 147.094 mg g-1 was observed in batch adsorption experiments, and the sorption isotherms were fit well by the Freundlich model of multilayer adsorption. Adsorption reached equilibrium rapidly in kinetic experiments and followed the pseudo-second-order kinetic model. The adsorption capacity of the ZnO x -MOF@MnO2 composite with the highest MnO2 content was high over a wide pH range, and the composite was highly selective toward Sr2+ in solutions containing coexisting competing ions. Also, it has a good reusability for removing Sr2+. Copyright © 2020 American Chemical Society.Porphyrin-based catalytic oxidation is one of the most representative biomimetic catalysis. To mimic the biomimetic catalytic oxidation of nature, a positive charged porous membrane, quaternized polysulfone (QPSf) membrane with spongelike structure, was prepared for supporting meso-tetraphenylsulfonato porphyrin (TPPS). The influence of polymer concentration, coagulation bath, and additives on the structure of the substrate membrane was explored, and the optimized membrane with porosity of 87.1% and water flux of 371 L·m-2·h-1 at 0.1 MPa was obtained. Monolayer TPPS was adsorbed on the QPSf membrane surface by the electrostatic self-assembly approach, and the adsorption process followed the pseudo second-order kinetic model and Langmuir adsorption isotherm equation. The resulting TPPS@QPSf membrane showed excellent visible light response, and the photocatalytic performance for dyes was then enhanced dramatically after TPPS was immobilized on the membrane. The removal efficiencies for rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) were 92.1, 94.1, and 92.1% under visible light irradiation, respectively. The primary photocatalytic degradation of the dye was a zero-order reaction, and the secondary reaction of degradation followed pseudo first-order kinetics. Finally, the TPPS@QPSf membrane can be reused for photocatalytic degradation of RhB for 10 cycles with no obvious change on removal efficiency, which indicated that this membrane is a promising material for dyeing water treatment coupled with visible light irradiation. Copyright © 2020 American Chemical Society.Large-grained and well-oriented methylammonium lead tribromide (MAPbBr3) perovskite was formed from the conversion of amorphous lead bromide (PbBr2) doped with phenethylamine (PEA). The addition of PEA ions (with an optimized molar ratio of 0.008%) to the PbBr2 solution assisted the formation of a smooth PEA-doped PbBr2 layer by spin-coating. Then, the PEA-doped PbBr2 thin film would convert into large-grained and well-oriented MAPbBr3 with the help of a solid-vapor reaction under a vaporized methylammonium bromide (MABr) and choline chloride (CC) atmosphere. Furthermore, both PEA and CC would passivate the defects of perovskite to improve the crystal quality of perovskite. By applying this perovskite layer in perovskite light-emitting diodes (PeLEDs), the maximum luminance and current efficiency of PeLEDs could reach 20,869 cd/m2 and 3.99 cd/A, respectively; these values are approximately five and three times larger than those of PeLEDs without PEA. The perovskite converted from spin-coated PbBr2 with a PEA dopant remarkably improved the luminance and current efficiency of its PeLEDs. Copyright © 2020 American Chemical Society.Dye-sensitized solar cells (DSSCs) are solar energy conversion devices with high efficiency and simple fabrication procedures. Developing transparent counter electrode (CE) materials for bifacial DSSCs can address the needs of window-type building-integrated photovoltaics (BIPVs). Herein, transparent organic-inorganic hybrid composite films of molybdenum disulfide and poly(3,4-ethylenedioxythiophene) (MoS2/PEDOT) are prepared to take full advantage of the conductivity and electrocatalytic ability of the two components. MoS2 is synthesized by hydrothermal method and spin-coated to form the MoS2 layer, and then PEDOT films are electrochemically polymerized on top of the MoS2 film to form the composite CEs. The DSSC with the optimized MoS2/PEDOT composite CE shows power conversion efficiency (PCE) of 7% under front illumination and 4.82% under back illumination. Compared with the DSSC made by the PEDOT CE and the Pt CE, the DSSC fabricated by the MoS2/PEDOT composite CE improves the PCE by 10.6% and 6.4% for front illumination, respectively. It proves that the transparent MoS2/PEDOT CE owes superior conductivity and catalytic properties, and it is an excellent candidate for bifacial DSSC in the application of BIPVs. Copyright © 2020 American Chemical Society.As an attractive renewable energy source, deep geothermal energy is increasingly explored. Granite is a typical geothermal reservoir rock type with low permeability, and hydraulic fracturing is a promising reservoir stimulation method which could obviously enhance the reservoir permeability. Previous hydraulic fracturing studies were mostly conducted on artificial samples and small cylindrical granites. The fracturing pressures of artificial samples and small real rock sample were much lower than that of field operation, and it was difficult to observe morphological changes in small rocks. Hence, this paper presents a hydraulic fracturing experimental study on large-scale granite with a sample size of 300 × 300 × 300 mm under high temperatures. Besides, injection flow rate is an important parameter for on-site hydraulic fracturing; previous studies usually only focused on breakdown pressure, and there is a lack of comprehensive analysis about fracturing pressure curves and fracturing characteristics caused by different injection flow rates.