New boron nitride porous monoliths with high efficiency and excellent adsorption applications were successfully fabricated by a brand-new and template-free method.

The separation of acetylene and carbon dioxide is an essential but challenging process owing to the similar molecular sizes and physical properties of the two gas molecules. Notably, these molecules usually exhibit different orientations in the pore channel. We report an adsorption site selective occupation strategy by taking advantage of differences in orientation to sieve the C2H2 from CO2 in a judiciously designed amine‐functionalized metal–organic framework, termed CPL‐1‐NH2. In this material, the incorporation of amino groups not only occupies the adsorption sites of CO2 molecules and shields the interaction of uncoordinated oxygen atom and CO2 molecules resulting in a negligible adsorption amount and a decrease in enthalpy of adsorption but also strengthened the binding affinity toward C2H2 molecules. This material thus shows an extremely high amount of C2H2 at low pressure and a remarkably high C2H2/CO2 IAST selectivity (119) at 1 bar and 298 K.

As a material candidate for solar-energy-conversion applications of the next generation, Si nanowires (SiNWs) are easy to prepare, [1][2][3] more tolerant to impurities than planar Si, [4,5] and have attracted significant research attention. Prototype devices such as solid-junction solar cells [6,7] and photoelectrochemical (PEC) cells [8][9][10][11][12] have been developed. As the conduction band edge of Si (ca. 4.05 V vs. vacuum) [13] is more negative than the water reduction potential (ca. 4

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Hardening of an Al 0.3 CoCrFeNi High entropy alloy via High-pressure torsion and thermal annealing, Materials Letters, http://dx. AbstractHigh-pressure torsion (HPT) and thermal annealing were applied to a face-centered cubic as-cast Al 0.3 CoCrFeNi high entropy alloy. Processing by HPT produced a nanostructure with a higher incremental hardness than in most HPT single-phase materials and subsequent annealing at appropriate temperatures gave an ordered body-centered cubic secondary phase with an additional increase in hardness. The highest hardness after HPT and annealing was approximately four times higher than for the as-cast alloy.

Previous studies have reported that high carbon contents in FeCoCrNiMn high-entropy alloys lead to carbides precipitating from the alloys. Typically, carbides are used to improve the strength of alloys but also lead to decreased ductility. However, the strength and ductility of alloys can be improved when carbides shape, size and distribution are carefully controlled. Therefore, a carbide-containing FeCoCrNiMn alloy with 2 at.-% carbon was prepared by arc melting, and its microstructure and mechanical properties were further tuned by cold rolling with subsequent annealing treatment. The yield strength and uniform elongation of the resultant alloy were excellent, reaching 581 MPa and 25%, respectively, due to the additive combination of various strengthening mechanisms, such as solid-solution hardening, grain-boundary hardening and precipitation hardening.

Micro/nano-motors (MNMs) that combine attributes of miniaturization and self-propelled swimming mobility have been explored for efficient environmental remediation in the past decades. However, their progresses in practical applications are now subject to several critical issues including a complicated fabrication process, low production yield, and high material cost. Herein, we propose a biotemplated catalytic tubular micromotor consisting of a kapok fiber (KF, abundant in nature) matrix and manganese dioxide nanoparticles (MnO2 NPs) deposited on the outer and inner walls of the KF and demonstrate its applications for rapid removal of methylene blue (MB) in real-world wastewater. The fabrication is straightforward via dipping the KF into a potassium permanganate (KMnO4) solution, featured with high yield and low cost. The distribution and amount of MnO2 can be easily controlled by varying the dipping time. The obtained motors are actuated and propelled by oxygen (O2) bubbles generated from MnO2-triggered catalytic decomposition of hydrogen peroxide (H2O2), with the highest speed at 615 μm/s (i.e., 6 body length per second). To enhance decontamination efficacy and also enable magnetic navigation/recycling, magnetite nanoparticles (Fe3O4 NPs) are adsorbed onto such motors via an electrostatic effect. Both the Fe3O4-induced Fenton reaction and hydroxyl radicals from MnO2-catalyzed H2O2 decomposition can account for the MB removal (or degradation). Results of this study, taken together, provide a cost-effective approach to achieve high-yield production of the MNMs, suggesting an automatous microcleaner able to perform practical wastewater treatment.

Whereas wide-bandgap metal oxides have been extensively studied for the photooxidation of water, their utilization for photoreduction is relatively limited. An important reason is the inability to achieve meaningful photovoltages with these materials. Using Cu 2 O as a prototypical photocathode material, it is now shown that the photovoltage barrier can be readily broken by replacing the semiconductor/water interface with a semiconductor/semiconductor one. A thin ZnS layer (ca. 5 nm) was found to form high-quality interfaces with Cu 2 O to increase the achievable photovoltage from 0.60 V to 0.72 V. Measurements under no net exchange current conditions confirmed that the change was induced by a thermodynamic shift of the flatband potentials rather than by kinetic factors. The strategy is compatible with efforts aimed at stabilizing the cathode that otherwise easily decomposes and with surface catalyst decorations for faster hydrogen evolution reactions. A combination of NiMo and CoMo dual-layer alloy catalysts was found to be effective in promoting hydrogen production under simulated solar radiation.