Ultrasmall NiS_(2)Nanocrystals Embedded in Ordered Macroporous Graphenic Carbon Matrix for Efficiently Pseudocapacitive Sodium Storage

Sodium-ion hybrid capacitor(SIHC)is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities,natural abundance,and low cost.However,overcoming the imbalance between slow Na^(+)reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge.Here,we propose the high-rate-performance NiS_(2)@OMGC anode material composed of monodispersed NiS_(2) nanocrystals(8.8±1.7 nm in size)and N,S-co-doped graphenic carbon(GC).The NiS_(2)@OMGC material has a three-dimensionally ordered macroporous(3DOM)morphology,and numerous NiS_(2) nanocrystals are uniformly embedded in GC,forming a core-shell structure in the local area.Ultrafine NiS_(2) nanocrystals and their nano-microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance(355.7 mAh/g at 20.0 A/g).A SIHC device fabricated using NiS_(2)@OMGC and commercial activated carbon(AC)cathode exhibits ultrahigh energy densities(197.4 Wh/kg at 398.8 W/kg)and power densities(43.9 kW/kg at 41.3 Wh/kg),together with a long life span.This outcome exemplifies the rational architecture and composition design of this type of anode material.This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications.

2D MXenes as Co-catalysts in Photocatalysis:Synthetic Methods

Since their seminal discovery in 2011,two-dimensional(2D)transition metal carbides/nitrides known as MXenes,that constitute a large family of 2D materials,have been targeted toward various applications due to their outstanding electronic properties.MXenes functioning as co-catalyst in combination with certain photocatalysts have been applied in photocatalytic systems to enhance photogenerated charge separation,suppress rapid charge recombination,and convert solar energy into chemical energy or use it in the degradation of organic compounds.The photocatalytic performance greatly depends on the composition and morphology of the photocatalyst,which,in turn,are determined by the method of preparation used.Here,we review the four different synthesis methods(mechanical mixing,self-assembly,in situ decoration,and oxidation)reported for MXenes in view of their application as co-catalyst in photocatalysis.In addition,the working mechanism for MXenes application in photocatalysis is discussed and an outlook for future research is also provided.

Advancing early warning and surveillance for zoonotic diseases under climate change:Interdisciplinary systematic perspectives

Zoonoses account for the majority of emerging infectious diseases and pose a serious threat to human and animal health.Under global warming and climate change,zoonoses are significantly affected by influencing hosts,vectors,and pathogen dynamics as well as their in-teractions.Traditional zoonoses surveillance relies on molecular or serological diagnostic methods to monitor pathogens from animal or patient samples,which may miss the early warning signs of pathogens spillover from the environment.Nowadays,new technologies such as remote sensing,environment-based screening,multi-omics,and big data science facilitate comprehensive active surveillance,offering great potential for early warning and prediction.Despite the recent technological advances,there is few reviews that explores the integration of cutting-edge technologies aimed at constructing a robust early warning system.Therefore,we discussed the opportunities,barriers,and limitations of interdisciplinary emerging technologies for exploring early warning and surveillance of zoonoses.This systematic review summarized a practical framework for early surveillance integrated with a modified SEIR model for zoonoses in the context of climate change.It also outlined challenges and future prospects in terms of data sharing,early detection of unknown zoonoses and the move towards global surveillance.

Recent development in metal halide perovskites synthesis to improve their charge-carrier mobility and photocatalytic efficiency

Over the past decade,all-inorganic metal halide perovskites(MHPs,CsPbX_(3):X=Cl,Br,I)have been widely investigated as promising materials for optoelectronic devices such as solar cells and light-emitting diodes.MHPs are defecttolerant,which allows tuning of their bandgap without altering their photophysical properties.From a fundamental point of view,MHPs are excellent candidates for photocatalytic reactions due to their light-harvesting capability,high photogenerated charge-carrier mobility,long diffusion lengths,and tunable bandgap energy.In this review,we provide an overview of various MHP engineering strategies(e.g.,surface,morphological,and structural modifications,heterojunction coupling,and encapsulation)which are directly linked to the charge-carrier mobility and lifetimes,and then to the photocatalytic efficiency.Specifically,we outline different synthetic approaches resulting in surface and morphological modifications,anion/cation substitution,metallic doping,coupling,and encapsulation that tremendously influence MHPs’stability,optical properties,and charge-carrier dynamics at variable time scales(from fs toμs).We also provide an in-depth evaluation of the MHPs for variable photoredox reactions,discussing how the optical and electronic properties help to improve their stability and efficiency.

多功能二维玻璃态石墨烯器件用于可见光-近红外光探测与挥发性液体传感

本文设计了基于二维玻璃态石墨烯的多功能器件.与本征石墨烯相比,扭曲的晶格结构打开了玻璃态石墨烯的带隙,表现出与石墨烯类似甚至更优异的光电探测与化学传感性能.由于玻璃态石墨烯与空气中的小分子间较强的相互作用,该器件受到光致脱附的影响更小,呈现出正的光响应.在405 nm的激光照射下,器件的响应率为0.22 A W^(-1),探测率为10^(10)Jones.此外,玻璃态石墨烯中的固有缺陷和应变可增强分析物的吸附,获得良好的化学传感性能.玻璃态石墨烯器件探测丙酮的信噪比为48,比石墨烯器件提高了50%以上.此外,对偏压和厚度有关的挥发性有机化合物(VOC)感测功能的分析表明,少层玻璃态石墨烯更为敏感.这项研究表明玻璃态石墨烯在集成光电探测和化学传感多功能器件方面具有巨大应用前景.

Negative permittivity derived from inductive characteristic in the percolating Cu/EP metacomposites

Recently,increasing attention has been concentrated on negative permittivity with the development of the emerging metamaterials composed of periodic array structures.However,taking facile preparation into consideration,it is important to achieve negative permittivity behavior based on materials'intrinsic properties rather than their artificially periodic structures.In this paper,we proposed to fabricate the percolating composites with copper dispersed in epoxy(EP)resin by a polymerization method to realize the negative permittivity behavior.When Cu content in the composites reached to 80 wt%,the conductivity abruptly went up by three orders of magnitudes,suggesting a percolation behavior.Below the percolation threshold,the conductivity spectra conform to Jonscher's power law;when the Cu/EP composites reached to percolating state,the conductivity gradually reduced in high frequency region due to the skin effect.It is indicated that the conductive mechanism changed from hopping conduction to electron conduction.In addition,the permittivity did not increase monotonously with the increase of Cu content in the vicinity of percolation threshold,due to the presence of leakage current.Meanwhile,the negative permittivity conforming to Drude model was observed above the percolation threshold.Further investigation revealed that there was a constitutive relationship between the permittivity and the reactance.When conductive fillers are slightly above the percolation threshold,the inductive characteristic derived from conductive percolating network leads to the negative permittivity.Such epsilon-negative materials can potentially be applied in novel electrical devices,such as high-power microwave filters,stacked capacitors,negative capacitance field effect transistors and coil-free resonators.In addition,the design strategy based on percolating composites provides an approach to epsilon-negative materials.

Supramolecular gating of guest release from cucurbit[7]uril using de novo design

Herein we computationally explore the modulation of the release kinetics of an encapsulated guest molecule from the cucurbit[7]uril(CB7)cavity by ligands binding to the host portal.We uncovered a correlation between the ligand-binding affinity with CB7 and the guest residence time,allowing us to rapidly predict the release kinetics through straightforward energy minimization calculations.These high-throughput predictions in turn enable a Monte-Carlo Tree Search(MCTS)to de novo design a series of cap-shaped ligand molecules with large binding affinities and boosting guest residence times by up to 7 orders of magnitude.Notably,halogenated aromatic compounds emerge as top-ranking ligands.Detailed modeling suggests the presence of halogen-bonding between the ligands and the CB7 portal.Meanwhile,the binding of top-ranked ligands is supported by^(1)H NMR and 2D DOSY-NMR.Our findings open up possibilities in gating of molecular transport through a nanoscale cavity with potential applications in nanopore technology and controlled drug release.