超级电容器石墨烯-聚苯胺复合材料的研究进展

超级电容器具有功率密度高、充放电速度快、循环寿命长和维护成本低的特点,在电动车动力电池领域具有潜在的应用前景。超级电容器性能主要由其电极材料所决定。聚苯胺易合成、理论比容量高,而且导电性能优异,作为超级电容器电极材料有很高的应用价值。但是,在长期使用过程中,它的体积容易发生膨胀或收缩,循环寿命差。为了解决这个问题,将聚苯胺与石墨烯复合可以扬长避短,充分利用两者之间的协同效应,赋予复合材料优异电化学电容性能。本文综述了超级电容器用石墨烯-聚苯胺复合材料的制备方法,包括原位聚合法、油水界面合成法、电化学合成法、层层自组装法等;提出了三维网状石墨烯和对石墨烯-聚苯胺复合材料进行改性来提高复合材料的电化学电容性能的思路。     

玉米醇溶蛋白高分子材料的制备与应用进展

作为一种天然高分子,玉米醇溶蛋白(Zein)具有疏水性、可降解性、抗菌性等特点。本文在介绍Zein结构、组成及性质的基础上,首先介绍了Zein的提取与脱色方法;然后,总结了通过小分子与高分子改性制备Zein基高分子材料的方法;最后,综述了基于Zein的高分子材料在食品、生物医药、纤维、粘合剂以及其他行业的应用研究进展。作为一类生物相容与生物可降解的天然高分子材料,Zein基材料在药物载体、食品包装、粘合剂等领域将具有更广泛的发展前景。     

新型锌铝水滑石紫外吸收剂的制备及其紫外吸收性能

以有机紫外吸收剂2-苯基苯并咪唑-5-磺酸(PBSA)、N,N-二甲氨基苯甲酸(DABA)为有机原料,采用共沉淀法,合成了有机紫外吸收剂插层水滑石Zn2Al-LDH/PBSA和Zn2Al-LDH/DABA,并测定了所得到的样品的XRD、FT IR、薄膜紫外吸收性质和氧化催化活性。结果表明,当有机紫外吸收剂以阴离子的形式进入水滑石层间后,仍有良好的紫外吸收性能并在可见光区有很好的透光性;通过测定插层水滑石的氧化催化活性,与纯有机物相比,Zn2Al-LDH/PBSA和Zn2Al-LDH/DABA的氧化催化活性明显降低。合成的新型的插层水滑石有望在防晒产品中得到应用。     

锰催化的C?C键生成反应研究进展

迄今为止,贵金属(铑、钯、钌等)在过渡金属催化的碳碳键生成反应中发挥着主导作用,然而使用廉价金属催化剂更符合可持续发展的要求。锰是地壳中含量排第三位的过渡金属,价格便宜,环境危害性小,有潜力成为贵金属催化剂的替代品并发挥其自身独特的反应性。尽管锰参与的当量反应有大量文献报道,目前锰催化的反应尤其是碳碳键生成反应的发展还不成熟,如何实现高效的催化循环是锰催化领域面临的主要难题之一。本文对锰催化的付-克烷基化反应、格氏试剂的酰化反应、偶联反应、碳金属化反应、自由基反应和碳氢键活化反应进行了综述。     

离子液体在锂离子电池中的应用研究进展

离子液体具有蒸汽压低、热稳定性好、不易挥发、溶解能力强、环境友好、电化学稳定窗口和液程范围宽等优点,在锂离子电池领域应用前景广泛。本文按照离子液体作为电解质溶剂、与传统电解质复配或与聚合物电解质结合的应用方式,总结其对电池的安全性和热稳定性的影响,并综述了近年来离子液体在锂离子电池电解质中的应用研究进展。     

Enzyme-Instructed Assemblies Enable Mitochondria Localization of Histone H2B in Cancer Cells

Presently, little is known of how the inter-organelle crosstalk impacts cancer cells owing to the lack of approaches that can manipulate inter-organelle communication in cancer cells. We found that a negatively charged, enzyme cleavable peptide (MitoFlag) enables the trafficking of histone protein H2B, a nuclear protein, to the mitochondria in cancer cells. MitoFlag interacts with the nuclear location sequence of H2B to block it from entering the nucleus. A protease on the mitochondria cleaves the Flag from the MitoFlag/H2B complex to form assemblies that retain H2B on the mitochondria and facilitate H2B entering the mitochondria. Adding NLS, replacing aspartic acid by glutamic acid residues, or changing the l - to d -aspartic acid residue on MitoFlag abolishes the trafficking of H2B into mitochondria of HeLa cells. As the first example of the enzyme-instructed self-assembly of a synthetic peptide for trafficking endogenous proteins, this work provides insights for understanding and manipulating inter-organelle communication in cells.     

Constructing a Super-Saturated Electrolyte Front Surface for Stable Rechargeable Aqueous Zinc Batteries

Rechargeable aqueous zinc batteries (RAZB) have been re-evaluated because of the superiority in addressing safety and cost concerns. Nonetheless, the limited lifespan arising from dendritic electrodeposition of metallic Zn hinders their further development. Herein, a metal–organic framework (MOF) was constructed as front surface layer to maintain a super-saturated electrolyte layer on the Zn anode. Raman spectroscopy indicated that the highly coordinated ion complexes migrating through the MOF channels were different from the solvation structure in bulk electrolyte. Benefiting from the unique super-saturated front surface, symmetric Zn cells survived up to 3000 hours at 0.5 mA cm⁻², near 55-times that of bare Zn anodes. Moreover, aqueous MnO₂–Zn batteries delivered a reversible capacity of 180.3 mAh g⁻¹ and maintained a high capacity retention of 88.9 % after 600 cycles with MnO₂ mass loading up to 4.2 mg cm⁻².     

CF3SO2Na as a Bifunctional Reagent: Electrochemical Trifluoromethylation of Alkenes Accompanied by SO2 Insertion to Access Trifluoromethylated Cyclic N-Sulfonylimines

An unprecedented electrochemical trifluoromethylation/SO₂ insertion/cyclization process has been achieved in an undivided cell in an atom-economic fashion. The protocol relies on tandem cyclization of N-cyanamide alkenes by using Langlois’ reagent as a source of both CF₃ and SO₂ under direct anodically oxidative conditions, in which two C−C bonds, two C−X bonds (N−S and S−C), and two rings were formed in a single operation. This transformation enabled efficient construction of various trifluoromethylated cyclic N-sulfonylimines from readily accessible materials.     

A Non-Conjugated Polymer Acceptor for Efficient and Thermally Stable All-Polymer Solar Cells

A non-conjugated polymer acceptor PF1-TS4 was firstly synthesized by embedding a thioalkyl segment in the mainchain, which shows excellent photophysical properties on par with a fully conjugated polymer, with a low optical band gap of 1.58 eV and a high absorption coefficient >10⁵ cm⁻¹, a high LUMO level of −3.89 eV, and suitable crystallinity. Matched with the polymer donor PM6, the PF1-TS4-based all-PSC achieved a power conversion efficiency (PCE) of 8.63 %, which is ≈45 % higher than that of a device based on the small molecule acceptor counterpart IDIC16. Moreover, the PF1-TS4-based all-PSC has good thermal stability with ≈70 % of its initial PCE retained after being stored at 85 °C for 180 h, while the IDIC16-based device only retained ≈50 % of its initial PCE when stored at 85 °C for only 18 h. Our work provides a new strategy to develop efficient polymer acceptor materials by linkage of conjugated units with non-conjugated thioalkyl segments.     

Facile Synthesis of Sub-Nanometric Copper Clusters by Double Confinement Enables Selective Reduction of Carbon Dioxide to Methane

Previous density-functional theory (DFT) calculations show that sub-nanometric Cu clusters (i.e., 13 atoms) favorably generate CH₄ from the CO₂ reduction reaction (CO₂RR), but experimental evidence is lacking. Herein, a facile impregnation-calcination route towards Cu clusters, having a diameter of about 1.0 nm with about 10 atoms, was developed by double confinement of carbon defects and micropores. These Cu clusters enable high selectivity for the CO₂RR with a maximum Faraday efficiency of 81.7 % for CH₄. Calculations and experimental results show that the Cu clusters enhance the adsorption of *H and *CO intermediates, thus promoting generation of CH₄ rather than H₂ and CO. The strong interactions between the Cu clusters and defective carbon optimize the electronic structure of the Cu clusters for selectivity and stability towards generation of CH₄. Provided here is the first experimental evidence that sub-nanometric Cu clusters facilitate the production of CH₄ from the CO₂RR.