| 3 | Rapid synthesis of transition metal dichalcogenide-carbon aerogel composites for supercapacitor electrodes显示文摘Transition metal dichalcogenide(TMD)materials have recently demonstrated exceptional supercapacitor properties after conversion to a metallic phase,which increases the conductivity of the network.However,freestanding,exfoliated transition metal dichalcogenide films exhibit surface areas far below their theoretical maximum(1.2%),can fail during electrochemical operation due to poor mechanical properties,and often require pyrophoric chemicals to process.On the other hand,pyrolyzed carbon aerogels exhibit extraordinary specific surface areas for double layer capacitance,high conductivity,and a strong mechanical network of covalent chemical bonds.In this paper,we demonstrate the scalable,rapid nanomanufacturing of TMD(MoS2 and WS2)and carbon aerogel composites,favoring liquid-phase exfoliation to avoid pyrophoric chemicals.The aerogel matrix support enhances conductivity of the composite and the synthesis can complete in 30 min.We find that the addition of transition metal dichalcogenides does not impact the structure of the aerogel,which maintains a high specific surface area up to 620 m^(2) g−1 with peak pore radii of 10 nm.While supercapacitor tests of the aerogels yield capacitances around 80 F g^(−1) at the lowest applied currents,the aerogels loaded with TMD’s exhibit volumetric capacitances up to 127% greater than the unloaded aerogels.In addition,the WS2 aerogels show excellent cycling stability with no capacitance loss over 2000 cycles,as well as markedly better rate capability and lower charge transfer resistance compared to their MoS2-loaded counterparts.We hypothesize that these differences in performance stem from differences in contact resistance and in the favorability of ion adsorption on the chalcogenides. | Matthew J.Crane Matthew B.Lim Xuezhe Zhou Peter J.Pauzauskie | 2017 | Microsystems & Nanoengineering2017，3，1： | 0 |
| 4 | Tbit/s line-rate satellite feeder links enabled by coherent modulation and full-adaptive optics显示文摘Free-space optical(FSO)communication technologies constitute a solution to cope with the bandwidth demand of future satellite-ground networks.They may overcome the RF bottleneck and attain data rates in the order of Tbit/s with only a handful of ground stations.Here,we demonstrate single-carrier Tbit/s line-rate transmission over a free-space channel of 53.42 km between the Jungfraujoch mountain top(3700 m)in the Swiss Alps and the Zimmerwald Observatory(895 m)near the city of Bern,achieving net-rates of up to 0.94 Tbit/s.With this scenario a satellite-ground feeder link is mimicked under turbulent conditions.Despite adverse conditions high throughput was achieved by employing a full adaptive optics system to correct the distorted wavefront of the channel and by using polarization-multiplexed high-order complex modulation formats.It was found that adaptive optics does not distort the reception of coherent modulation formats.Also,we introduce constellation modulation–a new four-dimensional BPSK(4D-BPSK)modulation format as a technique to transmit high data rates under lowest SNR.This way we show 53 km FSO transmission of 13.3 Gbit/s and 210 Gbit/s with as little as 4.3 and 7.8 photons per bit,respectively,at a bit-error ratio of 1∙10−3.The experiments show that advanced coherent modulation coding in combination with full adaptive optical filtering are proper means to make next-generation Tbit/s satellite communications practical. | Yannik Horst Bertold Ian Bitachon Laurenz Kulmer Jannik Brun Tobias Blatter Jean-Marc Conan Aurélie Montmerle-Bonnefois Joseph Montri Béatrice Sorrente Caroline B.Lim Nicolas Védrenne Daniel Matter Loann Pommarel Benedikt Baeuerle Juerg Leuthold | 2023 | Light(Science & Applications)2023，12，9： | 0 |
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