关键词：
Batteries;Green chemistry;Electrochemical energy storage;Electrode materials;Nanomaterials
摘要：
A simple strategy which combines the treatment of industrial wastewater with the preparation of electrode materials was proposed in this work. And the industrial wastewater is the only iron source for the material preparation. The preparation method in this work is facile, economical and environment-friendly which includes two simple steps of low-temperature aqueous solution and one-step calcination. Moreover two kinds of high performance Fe2O3 anode materials (alpha-/gamma-Fe2O3 nano spheres, respectively) with isomerism can be obtained by simply adjusting calcination temperatures. Both of the alpha-Fe2O3 and gamma-Fe2O3 nanospheres show good lithium storing reversibility when used as anode materials in LIBs. Furthermore the as-prepared alpha-Fe2O3 nano-electrode with lower electrochemical impedance exhibit a far better electrochemical performance (about 74.1% capacity retention (calculated based on the lithiation) from the 1st to 5th cycle) than the gamma-one (only 39.0% capacity retention from the 1st to 5th cycle). The results here provide economical yet environment-friendly strategies for developing advanced anode material demanding both high energy and long lifespan for full-cell lithium battery. (C) 2018 Elsevier Ltd. All rights reserved.
摘要：
Recent advances in the preparation and application of perovskite-type oxides as bifunctional electrocatalysts for oxygen reaction and oxygen evolution reaction in rechargeable metal-air batteries are presented in this review. Various fabrication methods of these oxides are introduced in detail, and their advantages and disadvantages are analyzed. Different preparation methods adopted have great influence on the morphologies and physicochemical properties of perovskite-type oxides. As a bifunctional electrocatalyst, perovskite-type oxides are widely used in rechargeable metal-air batteries. The relationship between the preparation methods and the performances of oxygen/air electrodes are summarized. This work is concentrated on the structural stability, the phase compositions, and catalytic performance of perovskite-type oxides in oxygen/air electrodes. The main problems existing in the practical application of perovskite-type oxides as bifunctional electrocatalysts are pointed out and possible research directions in the future are recommended.
摘要：
In this work, highly N/P co-doped porous carbons (NPCs) have been synthesized by an ultra facile, self-activation green strategy, only used L-histidine and phytic acid as precursors. With the benefit of the self-activation strategy of the precursors, no extra traditional activators are needed for porous structures of NPCs. The as-prepared NPC-0.5-800 sample displays high contents and uniform heteroatom doping (N: 5.4%, P: 6.3%, O: 12.14%), high specific surface area (787 m(2)/g) and large pore volume (0.43 cm(3)/g). These characteristics enable the NPC-0.5-800 sample to exhibit a good specific capacitance of 290.2 F g(-1) and a good cycling stability (95.0%) in a three-electrode system. Furthermore, the NPC-0.5-800-based symmetric supercapacitor in 1M NaSO4 electrolyte shows a high energy density (20.8Wh kg(-1)) at the current density of 1 A g(-1). Importantly, it exhibits excellent cycling performance (97.1% of capacitance retention after 5000 cycles). The work not only provides the self-activation green method to fabricate NPCs with good electrochemical performances, but also designs materials of different N/P content and pore size distribution for further supercapacitor applications. (C) 2019 The Electrochemical Society.
作者机构：
[Luo, S. N.; Tang, M. X.; Li, Y. X.; Zhang, Y. Y.; Tang, MX; Luo, SN; Fan, D.; Chen, S.; Zeng, X. L.; Zhang, N. B.; Huang, J. W.; Zhong, T.; Ye, S. J.] Peac Inst Multiscale Sci, Chengdu 610031, Sichuan, Peoples R China.;[Luo, S. N.; Lu, L.; Hou, H. M.] Southwest Jiaotong Univ, Minist Educ, Key Lab Adv Technol Mat, Chengdu 610031, Sichuan, Peoples R China.;[Luo, S. N.; Lu, L.; Hou, H. M.] Southwest Jiaotong Univ, Inst Mat Dynam, Chengdu 610031, Sichuan, Peoples R China.;[Wang, L.] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Sun, T.; Fezzaa, K.] Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA.
通讯机构：
[Zhang, YY; Tang, MX; Luo, SN] P;[Luo, S. N.] S;Peac Inst Multiscale Sci, Chengdu 610031, Sichuan, Peoples R China.;Southwest Jiaotong Univ, Minist Educ, Key Lab Adv Technol Mat, Chengdu 610031, Sichuan, Peoples R China.;Southwest Jiaotong Univ, Inst Mat Dynam, Chengdu 610031, Sichuan, Peoples R China.
摘要：
Deformation twinning plays a vital role in accommodating plastic deformation of hexagonal-close-packed (hcp) metals, but its mechanisms are still unsettled under high strain rate shock compression. Here we investigate deformation twinning in shock-compressed Mg as a typical hcp metal with in situ, ultrafast synchrotron x-ray diffraction. Extension twinning occurs upon shock compression along ⟨112¯0⟩ and ⟨101¯0⟩, but only upon release for loading along ⟨0001⟩. Such deformation mechanisms are a result of the polarity of deformation twinning, which depends on directionality and relative magnitude of resolved shear stress and may be common for Mg and its alloys in a wide range of strain rates.
摘要：
A widely applicably method is described for fluorometric determination of targets such as microRNA and viral DNA. It is making use of a Mg(II)-dependent DNAzyme and a G-quadruplex. In the absence of analyte, an inactive DNAzyme is formed by the hybridization of split DNAzymes and substrate. On addition of target analyte, the end of each strand of the split DNAzymes bind the analyte. This leads to the generation of an active DNAzyme. In the presence of Mg(II), the activated DNAzyme is formed and can cleave the substrate strand. Hence, the caged G-quadruplex sequences will be released. These released G-quadruplexes combine with thioflavin T to generate a G-quadruplex/thioflavin T complex and thereby cause amplified fluorescence. The method shows a 70 pM detection limit for H5N1 and works over a wide linear range 1 nM to 400 nM. Conceivably, this detection scheme has a wide scope in that it may be applied to other assays for microRNAs and DNAs by variation of the type of DNAzyme. Graphical abstractSchematic presentation of target detection: the DNAzyme cannot cleave the substrate strand when target is absent. Once the target is added, the active DNAzyme can cleave the substrate strand in the presence of Mg²⁺, resulting in significant fluorescence enhancement when the release of the caged G-quadruplex sequences binding with 2-[4-(dimethylamino)phenyl]-3,6-dimethylbenzothiazolium chloride (ThT).
作者：
Mao Xia;Li Yi-ran;Xiang Xiong;Wang Hu;Tang, Yi-wei;...
期刊：
Journal of Alloys and Compounds,2019年800:116-124 ISSN：0925-8388
通讯作者：
Zhi Zhou;Zhang, Hong-bo
作者机构：
[Nan Zhou; Li Yi-ran; Zhi Zhou; Tang, Yi-wei; Mao Xia] Hunan Agr Univ, Coll Sci, Hunan Prov Engn Technol Res Ctr Opt Agr, 1 Nongda Rd, Changsha 410128, Hunan, Peoples R China.;[Xiang Xiong; Mao Xia; Wang Hu; Zhang, Hong-bo] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Zhi Zhou] H;[Zhang, Hong-bo] C;Hunan Agr Univ, Coll Sci, Hunan Prov Engn Technol Res Ctr Opt Agr, 1 Nongda Rd, Changsha 410128, Hunan, Peoples R China.;Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Li-ion mobility;Piezoelectric material BaTiO3;Local electric potential;Silicon monoxide anode;Large volume expansion
摘要：
Silicon monoxide (SiO)-based negative materials have attracted widespread attention due to the low working potential and high specific capacity. However, the large volume dilation (about 200%) is adverse to the electrochemical performance of battery during the charge-discharge process. To overcome the disadvantage of volume change, much effort has been paid to minimize the volume expansion. Unfortunately, the volume change is inescapable no matter how to modify the SiO-based materials. Therefore, utilizing the characteristics of volume expansion to improve the electrochemical properties of SiO-based material is the most desirable method. Piezoelectric materials can generate local piezoelectric field when suffer from the mechanical stress, which serves as a driving force to accelerate the transmission speed of Li ion, result in the improve of electrochemistry performance. In this work, SiO@C/BaTiO3/Carbon nanotubes composites are successfully synthesized and served as anode materials for lithium ion batteries (LIBs). The SiO and BaTiO3 are dispersed uniformly in amorphous carbon matrix, the large volume expansion of SiO can transfer to the BaTiO3 via the carbon matrix. When the BaTiO3 nanoparticles poled, the piezoelectric potential is generated, which can promote the mobility of Li ion. Carbon nanotubes provides the transmission channel to accelerate the diffusion of Li ion, which is benefited to the constitution and structure of composite, the SiO@C/BaTiO3/Carbon nanotubes exhibit excellent electrochemical performance with a high charge capacity of 711.7 mAh g(-1) and a high capacity retention of 92.4% after 200 cycles at 100 mA g(-1). Experimental results suggest that the piezoelectric material BaTiO3 can enhance the electrochemical properties of SiO-based materials. (C) 2019 Elsevier B.V. All rights reserved.
通讯机构：
[Xiao, FH; Huang, HW] X;Xiangtan Univ, Coll Chem, Key Lab Environm Friendly Chem & Applicat, Minist Educ,Key Lab Green Organ Synth & Applicat, Xiangtan 411105, Peoples R China.
摘要：
A copper-catalyzed oxidative cyclization of oxime, arylthiol, and trifluoroacetic anhydride for the construction of trisubstituted oxazoles has been developed. This transformation combines N–O bond cleavage, C–H functionalization, and intramolecular annulation, providing a practical protocol for the introduction of a trifluoromethyl (−CF3) group at oxazole rings.
摘要：
Rechargeable lithium-sulfur (Li-S) batteries are a significant energy-storage device owing to their eco-friendliness and high theoretical energy density. However, the shuttle effect of soluble polysulfides as well as the slow redox kinetics constrains the development of Li-S batteries. Herein, carbon nanodots-decorated alveolate N, O, S tridoped hierarchical porous carbon (a-NOSPC) material is synthesized via facile pyrolysis of tobacco stem. The coexistence of micropores, mesopores, and macropore in the hierarchical porous carbon are beneficial for physical accommodating/immobilizing active materials sulfur and rapid charge/ion transfer. Meanwhile, the N, O, S dopants provide rich electrocatalytic active site in chemical binding of polysulfides and their accelerated redox kinetics, thus guaranteeing high utilization on active materials. The resultant a-NOSPC/S cathode with an 2.7 mg cm(-2) areal sulfur loading delivers a high reversible areal capacity of 2.90mAh cm(-2) at 0.1 C, maintaining 2.01mAh cm(-2) over 100 cycles, which is obviously superior to the most reported biochar-based electrodes. Our results provide an appealing avenue to the design of multifunctional sulfur host for advanced Li-S batteries. (C) 2019 Elsevier Ltd. All rights reserved.
