A robust synthesis route of confined carbyne

The unique mechanical,optical,and electrical properties of carbyne,a one-dimensional allotrope of carbon,make it a highly promising material for various applications.It has been demonstrated that carbon nanotubes(CNTs)can serve as an ideal host for the formation of confined carbyne(CC),with the yield being influenced by the quality of the carbon nanotubes for confinement and the carbon source for carbyne growth.In this study,a robust synthesis route of CC within CNTs is proposed.C70 was utilized as a precursor to provide an additional carbon source,based on its ability to supply more carbon atoms than C60 at the same filling ratio.Multi-step transformation processes,including defect creation,were designed to enhance the yield of CC.As a result,the yield of CC was significantly increased for the C70 encapsulated single-walled CNTs by more than an order of magnitude than the empty counterparts,which also surpasses that of the double-walled CNTs,making it the most effective route for synthesizing CC.These findings highlight the importance of the additional carbon source and the optimal pathway for CC formation,offering valuable insights for the application of materials with high yield.

Cu/Mo2C synthesized through Anderson-type polyoxometalates modulate interfacial water structure to achieve hydrogen evolution at high current density

The development of efficient non-precious metal catalysts is important for the large-scale application of alkaline hydrogen evolution reaction(HER).Here,we synthesized a composite catalyst of Cu and Mo_(2)C(Cu/Mo_(2)C)using Anderson-type polyoxometalates(POMs)synthesized by the facile soaking method as precursors.The electronic interaction between Cu and Mo_(2)C drives the positive charge of Cu,alleviating the strong adsorption of hydrogen at the Mo site by modulating the d-band center of Mo_(2)C.By studying the interfacial water structure using in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS),we determined that the positively charged Cu crystals have the function of activating water molecules and optimizing the interfacial water structure.The interfacial water of Cu/Mo_(2)C contains a large amount of free water,which could facilitate the transport of reaction intermediates.Due to activated water molecules and optimized interfacial water structure and hydrogen adsorption energy,the overpotential of Cu/Mo_(2)C is 24 mV at a current density of 10 mA·cm^(-2) and 178 mV at a current density of 1000 mA·cm^(-2).This work improves catalyst performance in terms of interfacial water structure optimization and deepens the understanding of water-mediated catalysis.

Constructing Br-Doped Li_(10)SnP_(2)S_(12)-Based All-Solid-State Batteries with Superior Performances

Ionic conductivity and electro/chemical compatibility of Li_(10)SnP_(2)S_(12) electrolytes play crucial roles in achieving superior electrochemical performances of the corresponding solid-state batteries.However,the relatively low Li-ion conductivity and poor stability of Li_(10)SnP_(2)S_(12) toward high-voltage layered oxide cathodes limit its applications.Here,a Br-substituted strategy has been applied to promote Li-ion conductivity.The optimal composition of Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) delivers high conductivity up to 6.0 mS cm^(−1).7Li static spin-lattice relaxation(T1)nuclear magnetic resonance(NMR)and density functional theory simulation are combined to unravel the improvement of Li-ion diffusion mechanism for the modified electrolytes.To mitigate the interfacial stability between the Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) electrolyte and the bare LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2) cathode,introducing Li_(2)ZrO_(3) coating layer and Li_(3)InCl_(6) isolating layer strategies has been employed to fabricate all-solid-state lithium batteries with excellent electrochemical performances.The Li_(3)InCl_(6)-LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)/Li_(3)InCl_(6)/Li_(9.9)SnP_(2)S_(11.9)Br_(0.1)/Li-In battery delivers much higher discharge capacities and fast capacity degradations at different charge/discharge C rates,while the Li_(2)ZrO_(3)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)/Li_(9.9)SnP_(2)S_(11.9)Br_(0.1)/Li-In battery shows slightly lower discharge capacities at the same C rates and superior cycling performances.Multiple characterization methods are conducted to reveal the differences of battery performance.The poor electrochemical performance of the latter battery configuration is associated with the interfacial instability between the Li_(3)InCl_(6) electrolyte and the Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) electrolyte.This work offers an effective strategy to constructing Li_(10)SnP_(2)S_(12)-based all-solid-state lithium batteries with high capacities and superior cyclabilities.

Carbon nanotube-dependent synthesis of armchair graphene nanoribbons

Sub-nanometer armchair graphene nanoribbons(GNRs)with moderate band gap have great potential towards novel nanodevices.GNRs can be synthesized in the confined tubular space of single-walled carbon nanotubes(SWCNTs),in which precursor molecules have been specifically designed to form the GNRs with certain width and edge.However,it is still unexplored how the diameter and metallicity of SWCNTs influence the synthesis of the GNRs.Herein,we applied a series of SWCNTs with different average diameters to study the diameter-dependent synthesis of GNRs.By using Raman spectroscopy and transmission electron microscopy,we found that the width of the GNRs can be tailored by the diameter of the SWCNTs.Especially,the SWCNTs with average diameter of 1.3 nm produced 6 and 7 armchair GNRs with the highest yield,which can be well explained by considering the width of the GNRs and van der Waals radius of hydrogen and carbon atoms.In addition,semiconducting and metallic SWCNTs produced GNRs with different yields,which could attribute to different diameter distributions and density of defects.These results enable the possibility of a high-yield production of certain armchair graphene nanoribbons in large scale,which would benefit future applications as semiconductor with sub-nanometer in width.

Microwave heating as a universal method to transform confined molecules into armchair graphene nanoribbons

Armchair graphene nanoribbons(AGNRs)with sub-nanometer width are potential materials for the fabrication of novel nanodevices thanks to their moderate direct band gaps.AGNRs are usually synthesized by polymerizing precursor molecules on substrate surface.However,it is time-consuming and not suitable for large-scale production.AGNRs can also be grown by transforming precursor molecules inside single-walled carbon nanotubes(SWCNTs)via furnace annealing,but the obtained AGNRs are normally twisted.In this work,microwave heating is applied for transforming precursor molecules into AGNRs.The fast heating process allows synthesizing the AGNRs in seconds.Several different molecules were successfully transformed into AGNRs,suggesting that it is a universal method.More importantly,as demonstrated by Raman spectroscopy,aberrationcorrected high-resolution transmission electron microscopy and theoretical calculations,less twisted AGNRs are synthesized by the microwave heating than the furnace annealing.Our results reveal a route for rapid production of AGNRs in large scale,which would benefit future applications in novel AGNRs-based semiconductor devices.