Array of nanosheets render ultrafast and high-capacity Na-ion storage by tunable pseudocapacitance

Sodium-ion batteries are a potentially low-cost and safe alternative to the prevailing lithium-ion battery technology. However, it is a great challenge to achieve fast charging and high power density for most sodium-ion electrodes because of the sluggish sodiation kinetics. Here we demonstrate a high-capacity and high-rate sodium-ion anode based on ultrathin layered tin(II) sulfide nanostructures, in which a maximized extrinsic pseudocapacitance contribution is identified and verified by kinetics analysis. The graphene foam supported tin(II) sulfide nanoarray anode delivers a high reversible capacity of ∼1,100 mAh g−1 at 30 mA g−1 and ∼420 mAh g−1 at 30 A g−1, which even outperforms its lithium-ion storage performance. The surface-dominated redox reaction rendered by our tailored ultrathin tin(II) sulfide nanostructures may also work in other layered materials for high-performance sodium-ion storage.Dongliang Chao, Changrong Zhu, Peihua Yang, Xinhui Xia, Jilei Liu, Jin Wang, Xiaofeng Fan, Serguei V. Savilov, Jianyi Lin, Hong Jin Fan, Ze Xiang She

Generation of ultra-short quasi-unipolar electromagnetic pulses from quasi-planar electron bunches

A method for the generation of quasi-unipolar pulses based on coherent synchrotron radiation from a quasi-planar electron bunch moving along a curved trajectory is proposed and theoretically studied. It is demonstrated that the experimental realization of this method at an existing installation (Terahertz to Optical Pulse Source) can result in generation of picosecond pulses with a peak power of up to 200 MW

Dehydration of Isobutyl Alcohol on Cesium-Cobalt-Containing NASICON Catalysts

Double and triple cobalt-containing phosphates Cs1–2xCoxZr2(PO4)3 (x = 0.15, 0.25, 0.50) with NASICON structure obtained by the sol–gel method were characterized using XRD, BET, XPS, and UV spectroscopy. The major isobutyl alcohol conversion reaction on these phosphates is dehydration. The triple phosphates have higher catalytic activity than the double phosphates in accord with a correlation between the yield of olefins and the concentration of acid sites on the catalyst surface. © 2017, Springer Science+Business Media New York

Dehydration of Isobutyl Alcohol on Cesium-Cobalt-Containing NASICON Catalysts

Double and triple cobalt-containing phosphates Cs1–2xCoxZr2(PO4)3 (x = 0.15, 0.25, 0.50) with NASICON structure obtained by the sol–gel method were characterized using XRD, BET, XPS, and UV spectroscopy. The major isobutyl alcohol conversion reaction on these phosphates is dehydration. The triple phosphates have higher catalytic activity than the double phosphates in accord with a correlation between the yield of olefins and the concentration of acid sites on the catalyst surface. © 2017, Springer Science+Business Media New York

Carboxylated and decarboxylated nanotubes studied by X-ray photoelectron spectroscopy

Carbon nanotubes (CNTs) of the conic and cylindrical structure were studied by X-ray photoelectron spectroscopy in the initial state and after carboxylation and decarboxylation reactions. The O=C - O and C - O groups were revealed on the surface of the chemically modified samples. It was found that both the carboxylated and decarboxylated cylindrical CNTs contain a smaller amount of oxygen than the corresponding conic CNTs apparently due to differences in their structures. © 2013 Springer Science+Business Media New York

Carboxylated and decarboxylated nanotubes studied by X-ray photoelectron spectroscopy

Carbon nanotubes (CNTs) of the conic and cylindrical structure were studied by X-ray photoelectron spectroscopy in the initial state and after carboxylation and decarboxylation reactions. The O=C - O and C - O groups were revealed on the surface of the chemically modified samples. It was found that both the carboxylated and decarboxylated cylindrical CNTs contain a smaller amount of oxygen than the corresponding conic CNTs apparently due to differences in their structures. © 2013 Springer Science+Business Media New York