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Designing highly active, low-cost, and bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts is urgent for the development of metal–air batteries. Herein, by density functional theory (DFT) calculations, we systematically reported a series of dual-metal atom adsorbed novel two-dimensional (2D) MBenes as efficient bifunctional catalysts for the OER/ORR (namely 2TM/TM1TM2–Mo2B2O2, TM = Mn, Fe, Co, Ni). Our theoretical results show that 2Ni–Mo2B2O2, FeCo–Mo2B2O2 and CoNi–Mo2B2O2 exhibit outstanding OER/ORR catalytic activity with overpotentials of 0.49/0.27 V, 0.38/0.50 V and 0.25/0.51 V, respectively, exceeding those of IrO2(110) for the OER and Pt(111) for the ORR. Additionally, these highly active bifunctional catalysts can effectively suppress the hydrogen evolution reaction (HER), ensuring the absolute preference for the OER/ORR. More importantly, the Bader charge (QTM) of adsorbed dual-metal atoms is used as a descriptor of OER/ORR catalytic activity, which is linearly related to ηORR and volcanically related to −ηOER. Our work not only provides new theoretical guidance for developing noble metal-free bifunctional electrocatalysts but also enriches the application of MBenes in electrocatalysis. [ABSTRACT FROM AUTHOR]

Random copolymerization of trimethylene carbonate (TMC) with L -lactide (LA) under mild conditions is a challenging task in polymer synthesis. Two amino-bridged bis(phenolate) neodymium complexes were synthesized and employed as efficient initiators for the copolymerization of TMC and L -LA under mild conditions to give random copolymers. NMR monitoring experiments of the chain microstructure versus polymerization time confirmed that a TMC/LA random copolymer was generated by a random copolymerization. [ABSTRACT FROM AUTHOR]

Designing heterostructured anode materials has been rendered supremely appealing to large-scale energy storage systems and storage device researchers. Recently, black phosphorene has experienced explosive development and been sought for widespread application in various domains including anode materials for electrochemistry. Hence, in this work, the black phosphorene/NP heterostructure (black P/NP) as a novel anode material for Li/Na batteries was systematically studied on the basis of first-principle calculations. Our simulations disclose that black P/NP is dynamically stable at room temperature and exhibits metallic properties. Charge density difference calculations and work function analysis demonstrate that electron charge transfer between the pristine single-layer components leads to enhanced Li/Na ion adsorption on the interlayer. To be specific, the calculated adsorption energies for Li/Na are −2.27 and −2.13 eV, respectively, which are sufficient to prevent metal aggregation during cycling. Besides, it is predicated that black P/NP has a positive and low open-circuit voltage. Excitingly, the diffusion barriers for Li and Na ions on black P/NP are 0.17 and 0.04 eV, respectively, which are superior to other typical heterostructures. Our results may be a new paradigm and reference for phosphorene-based heterostructures used as electrode materials of metal-ion batteries. [ABSTRACT FROM AUTHOR]

The development of cost-effective and highly efficient electrocatalysts for water splitting is highly desirable but remains an ongoing challenge. Numerous single-atom catalysts (SACs) have achieved satisfactory performances in this area; however, non-carbon metal-free substrates have been rarely explored. Herein, we report a series of single-metal atoms supported on a novel two-dimensional NP monolayer as promising electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) by theoretical calculations. Our results disclose that Ti@NP, V@NP and Ir@NP exhibit desirable catalytic activity for the HER with extremely low of −0.004, −0.051, and 0.017 eV, respectively. More importantly, the calculated activation barriers for the Tafel reactions of these SACs are much lower than those for the benchmark Pt catalysts. In addition, Pt@NP shows the lowest ηOER of 0.495 V, followed by Rh@NP (ηOER = 0.548 V), which are even superior to that of state-of-the-art IrO2. This work highlights the potential application of metal-free supports in SACs, which also further enriches the application of a NP monolayer in other related electrochemical processes. [ABSTRACT FROM AUTHOR]

Developing ranking anode materials with sufficient electrical conductivity, ultrafast ion diffusion ability and considerable storage capacity is of great importance for rechargeable ion batteries but still challenging. Herein, using first-principles calculations, the potential of monolayer Nb2N as an anode material for alkali metal (e.g., Li, Na, K and Ca) ion batteries (LIBs, SIBs, PIBs and CIBs) has been explored. The calculated results indicate that the Nb2N monolayer is dynamically and thermally stable with excellent electronic conductivity. To be specific, the Li, Na, K and Ca atoms can be steadily adsorbed on the Nb2N monolayer with a low adsorption energy of −0.996, −1.263, −1.568, and −1.401 eV, respectively. Impressively, the calculated low diffusion barriers for Li, Na, K and Ca on the Nb2N monolayer are 0.047, 0.029, 0.015 and 0.051 eV, respectively, implying its high performance for the ultrafast charge and discharge processes. More importantly, the maximum storage capacities are 536 mA h g−1 for LIBs and 1072 mA h g−1 for CIBs, which are much larger than those of common anode materials. This work not only demonstrates that the Nb2N monolayer can be used as a promising anode material but also inspires the future rational design of other nitride MXenes in energy conversion and storage devices. [ABSTRACT FROM AUTHOR]

Photocatalytic technology is a potential technology to meet energy and environmental requirements. Herein, the solvothermal method was used for the first time to synthesize a Bi2O2CO3/TiO2 hybrid with 0D/1D nanostructure, and the obtained materials were characterized systematically. In the architecture of the composite, Bi2O2CO3 quantum dots (QDs) (1.40–1.50 nm) uniformly grew on the surface of TiO2 nanobelts (NBs). The degradation efficiency of Rhodamine B under visible light irradiation was applied to evaluate the photocatalytic performance of the obtained materials. Of them, TB-3 exhibited the best photocatalytic performance, and more than 95.43% RhB was degraded under visible light. The reaction rate constant is 18.51 × 10−3 min−1, which is nine times larger than that of TiO2 NBs. Moreover, it exhibited remarkable stability and recyclability in a recycling experiment. According to the photoelectric characterization, the excellent performance may be attributed to the construction of a heterojunction and hybrid structure with 0D Bi2O2CO3 QDs and 1D TiO2 NBs, which endows the catalyst with faster migration of photo-generated carriers and less recombination of electron/hole pairs. Our work provides a promising method to build novel visible light-driven photocatalysts with a 0D/1D hybrid structure. [ABSTRACT FROM AUTHOR]

The transition-metal-catalyzed carboxylation of aryl and vinyl chlorides with CO2 is rarely studied, and has been achieved only with a Ni catalyst or combination of palladium and photoredox. In this work, the cobalt-catalyzed carboxylation of aryl and vinyl chlorides and bromides with CO2 has been developed. These transformations proceed under mild conditions and exhibit a broad substrate scope, affording the corresponding carboxylic acids in good to high yields. [ABSTRACT FROM AUTHOR]

The transition-metal-catalyzed carboxylation of aryl and vinyl chlorides with CO2 is rarely studied, and has been achieved only with a Ni catalyst or combination of palladium and photoredox. In this work, the cobalt-catalyzed carboxylation of aryl and vinyl chlorides and bromides with CO2 has been developed. These transformations proceed under mild conditions and exhibit a broad substrate scope, affording the corresponding carboxylic acids in good to high yields. [ABSTRACT FROM AUTHOR]

Proton-exchange membrane fuel cells have been reported as one of the most promising substitutes for fossil fuels. However, limited oxygen reduction reaction (ORR) kinetics on the cathode still remains the main bottleneck for commercialization. We report the synthesis of size-controllable monodisperse PtP2 nanoparticles (NPs) on nitrogen- and phosphorus-doped carbon (NPC) with initial ORR mass and specific activities of 0.466 A mgPt−1 and 0.438 mA cm−2 at 0.9 V in 0.1 M HClO4 solution, via a combined template and pyrolysis method. The activities increase to 0.724 A mgPt−1 and 0.508 mA cm−2 after 3000 potential cycles and remain stable for a further 20 000 cycles, exhibiting an obvious improvement over the commercial Pt benchmark (0.142 mA cm−2 and 0.098 A mgPt−1 at 0.9 V). The facilitated ORR activity of PtP2@NPC after incipient cycles of the stability test is due to the self-conversion process from PtP2 to core–shell Pt/PtP2 with a thin (≈1 nm) Pt shell and the consequential geometric and strain effects of the Pt skin which contribute to both the robustness and catalytic efficiency of the catalysts. Meanwhile, a four-electron pathway towards the ORR also indicates the high selectivity of our catalyst. Combined computational analysis indicates that the core–shell structure intensifies ORR activity by a more feasible rate-determining step and lower d-band center value. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting is a promising strategy for green and renewable energy development by transforming electrical energy into hydrogen energy. Herein, we report a series of flower-like electrocatalysts with cation-tunable (NixFe1−x)2P nanoparticles encapsulated by porous graphitized carbon films (GCs) via the combination of morphology control and component adjustment. By progressively tailoring the atomic ratios of Ni/Fe, the electronic structure and electrocatalytic activities of (NixFe1−x)2P can be intriguingly modified to achieve versatile catalytic behavior for both the HER and the OER. DFT calculations also validate that the (NixFe1−x)2P with an optimal atomic ratio of Ni/Fe can support the ‖ΔGH*‖ to be close to the optimum and decrease the adsorption energy for water, which can boost the water splitting. Meanwhile, anchoring the adjustable (NixFe1−x)2P nanoparticles into GC interlayers can endow these composites with more available active sites, excellent conductivity and enhanced stability. In fact, the combined synergistic effect of cation-tuned (NixFe1−x)2P nanoparticles and porous conductive GCs is the reason that these composites exhibit enhanced electrocatalytic activities, as illustrated by a low overpotential of 206 mV at j = 10 mA cm−2 (256 mV at j = 50 mA cm−2) for the OER. Meanwhile, the bifunctional (Ni0.75Fe0.25)2P@GCs, as both the cathode and anode of an electrolyzer, effectuates an ultra-small cell potential of 1.541 V at j = 10 mA cm−2 (1.573 V at j = 20 mA cm−2) for 30 h during electrolysis of water, rivaling commercial IrO2 and Pt/C catalysts. More importantly, this work can provide a way of fabricating cost-saving, component-tunable and high-efficiency bimetallic electrocatalysts for water splitting. [ABSTRACT FROM AUTHOR]

A hexapeptide derived from an enzyme inhibitor was used as an affinity ligand for the conjugation of a hydrophilic polymer to the enzyme. The peptide targeted the polymer to the “berth” of the inhibitor in the enzyme, affording the enzyme resistance to the inhibitor without affecting the enzymatic activity. [ABSTRACT FROM AUTHOR]

Devices that function in contact with blood are ubiquitous in clinical medicine and biotechnology. These devices include vascular grafts, coronary stents, heart valves, catheters, hemodialysers, heart-lung bypass systems and many others. Blood contact generally leads to thrombosis (among other adverse outcomes), and no material has yet been developed which remains thrombus-free indefinitely and in all situations: extracorporeally, in the venous circulation and in the arterial circulation. In this article knowledge on blood-material interactions and "thromboresistant" materials is reviewed. Current approaches to the development of thromboresistant materials are discussed including surface passivation; incorporation and/or release of anticoagulants, antiplatelet agents and thrombolytic agents; and mimicry of the vascular endothelium. [ABSTRACT FROM AUTHOR]

Agarose-derived agaro-oligosaccharides (AgaroS) have been extensively studied in terms of structures and bioactivities; they reportedly possess antioxidant and anti-inflammatory activities that maintain intestinal homeostasis and host health. However, the protective effects of AgaroS on deoxynivalenol (DON)-induced intestinal dysfunction remain unclear. We investigated the effects of AgaroS on DON-induced intestinal dysfunction in mice and explored the underlying protective mechanisms. In total, 32 mice were randomly allocated to four treatments ( n = 8 each) for 28 days. From day 1 to day 21, the control (CON) and DON groups received oral phosphate-buffered saline (200 μL per day); the AgaroS and AgaroS + DON groups received 200 mg AgaroS per kg body weight once daily by orogastric gavage. Experimental intestinal injury was induced by adding DON (4.8 mg per kg body weight) via gavage from day 21 to day 28. Phosphate-buffered saline was administered once daily by gavage in the CON and AgaroS groups. Herein, AgaroS supplementation led to a higher final body weight and smaller body weight loss and a lower concentration of plasma inflammatory cytokines, compared with the DON group. The DON group showed a significantly reduced ileal villus height and villus height/crypt depth, compared with the CON and AgaroS + DON groups. However, AgaroS supplementation improved DON-induced intestinal injury in mice. Compared with the DON group, ileal and colonic protein expression levels of claudin, occludin, Ki67, and mucin2 were significantly higher in the AgaroS supplementation group. Colonic levels of the anti-inflammatory cytokine IL-1β tended to be higher in the DON group than in the AgaroS + DON group. AgaroS altered the gut microbiota composition, accompanied by increased production of short-chain fatty acids in mice. In conclusion, our findings highlight a promising anti-mycotoxin approach whereby AgaroS alleviate DON-induced intestinal inflammation by modulating intestinal barrier functional integrity and gut microbiota in mice.

Developing ranking anode materials with sufficient electrical conductivity, ultrafast ion diffusion ability and considerable storage capacity is of great importance for rechargeable ion batteries but still challenging. Herein, using first-principles calculations, the potential of monolayer Nb2N as an anode material for alkali metal (e.g., Li, Na, K and Ca) ion batteries (LIBs, SIBs, PIBs and CIBs) has been explored. The calculated results indicate that the Nb2N monolayer is dynamically and thermally stable with excellent electronic conductivity. To be specific, the Li, Na, K and Ca atoms can be steadily adsorbed on the Nb2N monolayer with a low adsorption energy of -0.996, -1.263, -1.568, and -1.401 eV, respectively. Impressively, the calculated low diffusion barriers for Li, Na, K and Ca on the Nb2N monolayer are 0.047, 0.029, 0.015 and 0.051 eV, respectively, implying its high performance for the ultrafast charge and discharge processes. More importantly, the maximum storage capacities are 536 mA h g-1 for LIBs and 1072 mA h g-1 for CIBs, which are much larger than those of common anode materials. This work not only demonstrates that the Nb2N monolayer can be used as a promising anode material but also inspires the future rational design of other nitride MXenes in energy conversion and storage devices.

The transition-metal-catalyzed carboxylation of aryl and vinyl chlorides with CO2 is rarely studied, and has been achieved only with a Ni catalyst or combination of palladium and photoredox. In this work, the cobalt-catalyzed carboxylation of aryl and vinyl chlorides and bromides with CO2 has been developed. These transformations proceed under mild conditions and exhibit a broad substrate scope, affording the corresponding carboxylic acids in good to high yields.