Constructing a hollow core-shell structure of RuO_(2) wrapped by hierarchical porous carbon shell with Ru NPs loading for supercapacitor

Hollow core-shell structure nanomaterials have been broadly used in energy storage, catalysis, reactor,and other fields due to their unique characteristics, including the synergy between different materials,a large specific surface area, small density, large charge carrying capacity and so on. However, their synthesis processes were mostly complicated, and few researches reported one-step encapsulation of different valence states of precious metals in carbon-based materials. Hence, a novel hollow core-shell nanostructure electrode material, RuO_(2)@Ru/HCs, with a lower mass of ruthenium to reduce costs was constructed by one-step hydrothermal method with hard template and co-assembled strategy, consisting of RuO_(2) core and ruthenium nanoparticles(Ru NPs) in carbon shell. The Ru NPs were uniformly assembled in the carbon layer, which not only improved the electronic conductivity but also provided more active centers to enhance the pseudocapacitance. The RuO_(2) core further enhanced the material’s energy storage capacity. Excellent capacitance storage(318.5 F·g^(-1)at 0.5 A·g^(-1)), rate performance(64.4%) from 0.5 A·g^(-1)to 20 A·g^(-1), and cycling stability(92.3% retention after 5000 cycles) were obtained by adjusting Ru loading to 0.92%(mass). It could be attributed to the wider pore size distribution in the micropores which increased the transfer of electrons and protons. The symmetrical supercapacitor device based on RuO_(2)@Ru/HCs could successfully light up the LED lamp. Therefore, our work verified that interfacial modification of RuO_(2) and carbon could bring attractive insights into energy density for nextgeneration supercapacitors.

促进物理化学在线教学质量的实践

在疫情特殊时期,立足以学生的学习为中心,依托物理化学国家精品MOOC、利用“慕课堂+QQ群+腾讯会议”网络技术,构建了“五步法”在线教学模式,即“导学助力→MOOC自学→在线评测→及时反馈→讨论进阶”。充分发挥教师的主导作用,采用多样化的在线教学交互策略,激励、引导学生参与教学全过程,有效保障了在线教学质量。

Polyaniline-based electrocatalysts through emulsion polymerization:Electrochemical and electrocatalytic performances

One of the major challenges associated with fuel cells is the design of highly efficient electrocatalysts to reduce the high overpotential of the oxygen reduction reaction (ORR). Here we report Polyaniline (PANI) based micro/nanomaterials with or without transition metals, prepared by the emulsion polymerization and subsequent heat treatment. PANI microspheres with the diameter of about 0.7 mu m have been prepared in basic (NH3 solution) condition, using two different types of surfactant (CTAB, SDS) as the stabilizer, ammonium persulphate (APS) as oxidant with aniline/surfactants molar ratio at 1/1 under the hydrothermal treatment. PANI nanorods, Fe-PANI, and Fe-Co-PANI have been synthesized in acidic (HCI) medium with aniline/surfactants molar ratio at 1/2 and polymerization carried out without stirring for 24 h. Products mainly Fe-Co-PANI have shown high current density with increasing sweep rate and excellent specific capacitance 1753 F/g at the scan rate of 1 mV/s. Additionally, it has shown high thermal stability by thermogravimetric analysis (TGA). Fe-PANI has been investigated for excellent performance toward ORR with four electron selectivity in the basic electrolyte. The PANI-based catalysts from emulsion polymerization demonstrate that the method is valuable for making non-precious metal heterogeneous electrocatalysts for ORR or energy storage and conversion technology. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Biomedical Applications of DNA-Nanomaterials Based on Metallic Nanoparticles and DNA Self-Assembled Nanostructures

DNA is the carrier of genetic information, and its sequence can be designed to realize many important functions, including DNAzyme, aptamer and even structurally precise nanomaterials. The development of DNA nanotechnol- ogy combined functional nucleic acids with nanomaterials for various effective biomedical applications. Here, we reviewed the application of DNA-nanomaterials in two biomedical fields： early diagnosis and drug delivery. And in each field, we mainly focused on two kinds of nanomaterials： metallic nanoparticles and DNA self-assembled na- nomaterials. DNA metallic nanomaterials showed unique optical, electronic and magnetic properties in bioanalysis, and when functioned by DNA, their specificity was improved for both biosensor development and drug delivery. More recently, many DNA self-assembled nanomaterials were introduced into biomedical application for their well-defined structure and excellent biocompatibility. We summarized the research of these two kinds of DNA- nanomaterials for biomedical purposes, and finally made some prospection about their future development.

HREELS study on coadsorption of oxygen and cyclohexanone on the Pt(111) surface

The coadsorption of cyclohexanone and oxygen on Pt(111) has been investigated by HREELS and TDS. At 205 K the presence of oxygen induces an "extra" red\|shift of the C--O stretching of coadsorbed cyclohexanone. Heating this coadsorbed surface from 205 to 250 K leads to further dehydrogenation to form intermediate species and to complete disappearance of the C--O stretching band. Above 300 K, the molecule rings of dehydrogenation species cleave to form hydrocarbon fragments and CO molecules which directly desorb into the vacuum or react with preadsorbed oxygen to produce CO\-2 which leave the surface immediately. TDS results provide further evidence that the preadsorbed oxygen promotes the decomposition of cyclohexanone.