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41.
Constructing multifunctional interphases to suppress the rampant Zn dendrite growth and detrimental side reactions is crucial for Zn anodes. Herein, a phytic acid (PA)-ZnAl coordination compound is demonstrated as a versatile interphase layer to stabilize Zn anodes. The zincophilic PA-ZnAl layer can manipulate Zn2+ flux and promote rapid desolvation kinetics, ensuring the uniform Zn deposition with dendrite-free morphology. Moreover, the robust PA-ZnAl protective layer can effectively inhibit the hydrogen evolution reaction and formation of byproducts, further contributing to the reversible Zn plating/stripping with high Coulombic efficiency. As a result, the Zn@PA-ZnAl electrode shows a lower Zn nucleation overpotential and higher Zn2+ transference number compared with bare Zn. The Zn@PA-ZnAl symmetric cell exhibits a prolonged lifespan of 650 h tested at 5 mA cm−2 and 5 mAh cm−2. Furthermore, the assembled Zn battery full cell based on this Zn@PA-ZnAl anode also delivers decent cycling stability even under harsh conditions.  相似文献   
42.
Precise manipulation of the coordination environment of single-atom catalysts (SACs), particularly the simultaneous engineering of multiple coordination shells, is crucial to maximize their catalytic performance but remains challenging. Herein, we present a general two-step strategy to fabricate a series of hollow carbon-based SACs featuring asymmetric Zn−N2O2 moieties simultaneously modulated with S atoms in higher coordination shells of Zn centers (n≥2; designated as Zn−N2O2−S). Systematic analyses demonstrate that the synergetic effects between the N2O2 species in the first coordination shell and the S atoms in higher coordination shells lead to robust discrete Zn sites with the optimal electronic structure for selective O2 reduction to H2O2. Remarkably, the Zn−N2O2 moiety with S atoms in the second coordination shell possesses a nearly ideal Gibbs free energy for the key OOH* intermediate, which favors the formation and desorption of OOH* on Zn sites for H2O2 generation. Consequently, the Zn−N2O2−S SAC exhibits impressive electrochemical H2O2 production performance with high selectivity of 96 %. Even at a high current density of 80 mA cm−2 in the flow cell, it shows a high H2O2 production rate of 6.924 mol gcat−1 h−1 with an average Faradaic efficiency of 93.1 %, and excellent durability over 65 h.  相似文献   
43.
首先采用溶液共混法制备出石墨烯-碳纳米管(G-CNT)/聚氨酯(TPU)复合材料,然后通过拉伸实验及扫描电子显微镜(SEM)表征来考察该材料的拉伸强度和微波自修复特性,并从力学及材料与微波之间的相互作用等角度对其拉伸强度增强和微波修复机理进行研究.结果表明:在拉伸强度方面,与单一的石墨烯或CNT增强TPU相比,G-CNT之间形成的协同效应使TPU拉伸强度得到进一步提高,当石墨烯和CNT的质量比为3∶1时,G-CNT/TPU抗拉强度较纯TPU提高了67%,较G/TPU提高了18%,较CNT/TPU提高了25%;在材料裂纹的微波修复方面,石墨烯和CNT之间的协同效应使TPU材料自修复效果得到有效提高,当石墨烯和CNT的质量比为3∶1时,G-CNT/TPU修复效果达到最高值117%.  相似文献   
44.
We present an economical catalytic procedure to convert readily available 1,2‐diaminobenzenes and terminal epoxides into valuable 1,2,3,4‐tetrahydroquinoxalines in a highly enantioselective fashion. This procedure operates through relay zinc and iridium catalysis, and achieves redox‐neutral and stereoconvergent production of valuable chiral heterocycles from racemic starting materials with water as the only side product. The use of commercially available reagents and catalysts and a convenient procedure also make this catalytic method attractive for practical application.  相似文献   
45.
蒋云波  李欢欢  陶冶  陈润锋  黄维 《化学进展》2019,31(8):1116-1128
热活化延迟荧光(TADF)聚合物,不仅具有小分子TADF材料高的激子利用效率特性,而且还具备分子多样性好、可溶液加工、低成本、以及易实现大面积柔性器件等诸多优势,在近几年受到广泛的关注并展现了良好的应用前景。本文从TADF聚合物分子设计原理、器件结构及发光机理出发,依据TADF聚合物的构筑方法不同,概括了其结构设计策略,详述了各种类型TADF聚合物的分子结构和光电性能及其在有机电致发光器件领域应用的研究进展,最后探讨了TADF聚合物存在的问题,并展望了其发展前景。  相似文献   
46.
Metal sulfides have received considerable attention for efficient sodium storage owing to their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium‐ion batteries. Herein, an elegant multi‐step templating strategy has been developed to rationally synthesize hierarchical double‐shelled nanoboxes with the CoS2 nanosheet‐constructed outer shell supported on the CuS inner shell. Their structure and composition enable these hierarchical CuS@CoS2 nanoboxes to show boosted electrochemical properties with high capacity, outstanding rate capability, and long cycle life.  相似文献   
47.
Low-temperature synthesis of allyl dimethylamine (ADA) by selective heating under microwave irradiation (MI) used for water treatment is investigated. The effect of MI, ultrasound irradiation (UI) and conventional heating on yield of ADA, reaction time and the flocculation efficiency of polydiallyl dimethylammunion chloride (PDADMAC) prepared form ADA were studied. The results show that by selective heating at low temperature, MI not only increases yield of ADA and reduces reaction time, but also greatly enhances the flocculation efficiency of PDADMAC.  相似文献   
48.
通过样品处理、谱线选择、准确度和精密度测定、加标回收实验及与其他测定方法的比对实验,建立了电感耦合等离子体原子发射光谱法(ICP-AES)测定粗锑中As、Bi、Cd 、Cu、Fe、Pb、Se 7种元素的定量分析方法。实验结果表明,该方法准确度高,稳定可靠,相对标准偏差(RSD,n=6)均小于3%,方法的加标回收率在95~105%之间,分析结果与分光光度法、原子吸收光谱法(AAS)及原子荧光光谱法(AFS)分析结果相吻合,能够满足日常对粗锑中杂质元素含量测定的要求。  相似文献   
49.
High sensitive immunoassay platforms have gained intense attention due to their vital roles in early-stage disease diagnosis and therapeutic information feedback.Although random covalent-binding of antibody has been widely adopted in immunoassays due to its simplicity and effectiveness,it readily loses its activity and fails to exhibit high antigen-binding capacity.In this work,copolymer of zwitterionic sulfobetaine methacrylate (SBMA) and glycidyl methacrylate (GMA) brushes were immobilized onto inert polypropylene (PP) via surface-initiated atom transfer radical polymerization (ATRP) based on biomimetic dopamine pretreatment.Subsequently,boronic acid (BA) groups were covalently bonded via active GMA units,followed by the introduction of oriented immobilization of antibody.Owing to the oriented immobilization of antibody facilitated by BA groups in polymer brush,the bioactivity of antibody is well preserved,which endows the surface with significantly enhanced antigen-binding capacity.Moreover,the existence of SBMA segments in polymer brushes renders the surface high resistance to nonspecific protein adsorption,significantly alleviating the signal interference of antigen recognition.This strategy could find potential applications in developing high sensitive immunoassay platforms based on the different substrates.  相似文献   
50.
十二烷基甜菜碱/十二烷基硫酸钠复配体系的表面活性   总被引:29,自引:0,他引:29  
研究了两性表面活性剂十二烷基甜菜碱(C12BE)和阴离子型表面活性剂十二烷基硫酸钠(SDS)复配体系的形成胶束能力,降低表面张力效率,降低表面张力能力三种增效作用.发现C12BE和SDS摩尔比为6 :4时增效作用最显著.并考察了盐、醇对复配体系表面活性的影响,结果表明,加盐能导致表面活性的提高,加醇的机理比较复杂,乙醇对复配体系表面活性影响不大,而正丁醇影响则比较显著.  相似文献   
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