Large‐area phosphorus‐doped carbon nanosheets (P‐CNSs) are first obtained from carbon dots (CDs) through self‐assembly driving from thermal treatment with Na catalysis. This is the first time to realize the conversion from 0D CDs to 2D nanosheets doped with phosphorus. The sodium storage behavior of phosphorus‐doped carbon material is also investigated for the first time. As anode material for sodium‐ion batteries (SIBs), P‐CNSs exhibit superb performances for electrochemical storage of sodium. When cycled at 0.1 A g−1, the P‐CNSs electrode delivers a high reversible capacity of 328 mAh g−1, even at a high current density of 20 A g−1, a considerable capacity of 108 mAh g−1 can still be maintained. Besides, this material also shows excellent cycling stability, at a current density of 5 A g−1, the reversible capacity can still reach 149 mAh g−1 after 5000 cycles. This work will provide significant value for the development of both carbon materials and SIBs anode materials.
The coronavirus disease 19 is quickly spreading across China and globally. Pharmacy services are an important pillar in public health to prevent and contain the COVID-19 pandemic. Chinese pharmacists have acted swiftly in the public health response in China, such as drafting professional service guidance to pharmacists and pharmacies, establishing emergency drug formularies, monitoring and resolving drug shortages, establishing remote pharmacy services to prevent human-to-human infections, providing event-driven pharmaceutical care, educating the public on infection prevention and disease management, and participating in clinical trials and drug evaluation. This commentary reviews the unique needs of pharmacy services in the COVID-19 pandemic, and shares our experiences with the international pharmacy community in the response to these needs.
Discussed are the recent experimental and theoretical results on palladium-based catalysts for selective hydrogenation of alkynes obtained by a number of collaborating groups in a joint multi-method and multi-material approach. The critical modification of catalytically active Pd surfaces by incorporation of foreign species X into the sub-surface of Pd metal was observed by in situ spectroscopy for X=H, C under hydrogenation conditions. Under certain conditions (low H2 partial pressure) alkyne fragmentation leads to formation of a PdC surface phase in the reactant gas feed. The insertion of C as a modifier species in the sub-surface increases considerably the selectivity of alkyne semi-hydrogenation over Pd-based catalysts through the decoupling of bulk hydrogen from the outmost active surface layer. DFT calculations confirm that PdC hinders the diffusion of hydridic hydrogen. Its formation is dependent on the chemical potential of carbon (reactant partial pressure) and is suppressed when the hydrogen/alkyne pressure ratio is high, which leads to rather unselective hydrogenation over in situ formed bulk PdH. The beneficial effect of the modifier species X on the selectivity, however, is also present in intermetallic compounds with X=Ga. As a great advantage, such PdxGay catalysts show extended stability under in situ conditions. Metallurgical, clean samples were used to determine the intrinsic catalytic properties of PdGa and Pd3Ga7. For high performance catalysts, supported nanostructured intermetallic compounds are more preferable and partial reduction of Ga2O3, upon heating of Pd/Ga2O3 in hydrogen, was shown to lead to formation of PdGa intermetallic compounds at moderate temperatures. In this way, Pd5Ga2 and Pd2Ga are accessible in the form of supported nanoparticles, in thin film models, and realistic powder samples, respectively
Carbon dots inducing petal-like rutile TiO wrapped by ultrathin graphene-rich layers are proposed to fabricate superior anodes for sodium-ion batteries, featuring high-rate capabilities and long-term cyclelife, benefiting from promoted electron transport and a shortened Na diffusion length. High capacities of 144.4 mA h g (at 837.5 mA g ) after 1100 cycles and 74.6 mA h g (at 3350 mA g ) after 4000 cycles are delivered outstandingly.
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