[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

A facile process was developed to synthesize layered MoS2/graphene (MoS2/G) composites by an l-cysteine-assisted solution-phase method, in which sodium molybdate, as-prepared graphene oxide (GO), and l-cysteine were used as starting materials. As-prepared MoS2/G was then fabricated into layered MoS2/G composites after annealing in a H2/N2 atmosphere at 800 °C for 2 h. The samples were systematically investigated by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. Electrochemical performances were evaluated in two-electrode cells versus metallic lithium. It is demonstrated that the obtained MoS2/G composites show three-dimensional architecture and excellent electrochemical performances as anode materials for Li-ion batteries. The MoS2/G composite with a Mo:C molar ratio of 1:2 exhibits the highest specific capacity of ∼1100 mAh/g at a current of 100 mA/g, as well as excellent cycling stability and hig...

L-cysteine-assisted synthesis of layered MoS₂/graphene composites with excellent electrochemical performances for lithium ion batteries.

Isothermal amplification of nucleic acids is a simple process that rapidly and efficiently accumulates nucleic acid sequences at constant temperature. Since the early 1990s, various isothermal amplification techniques have been developed as alternatives to polymerase chain reaction (PCR). These isothermal amplification methods have been used for biosensing targets such as DNA, RNA, cells, proteins, small molecules, and ions. The applications of these techniques for in situ or intracellular bioimaging and sequencing have been amply demonstrated. Amplicons produced by isothermal amplification methods have also been utilized to construct versatile nucleic acid nanomaterials for promising applications in biomedicine, bioimaging, and biosensing. The integration of isothermal amplification into microsystems or portable devices improves nucleic acid-based on-site assays and confers high sensitivity. Single-cell and single-molecule analyses have also been implemented based on integrated microfluidic systems. In this review, we provide a comprehensive overview of the isothermal amplification of nucleic acids encompassing work published in the past two decades. First, different isothermal amplification techniques are classified into three types based on reaction kinetics. Then, we summarize the applications of isothermal amplification in bioanalysis, diagnostics, nanotechnology, materials science, and device integration. Finally, several challenges and perspectives in the field are discussed.

Isothermal Amplification of Nucleic Acids

Compressive surface strains have been necessary to boost oxygen reduction reaction (ORR) activity in core/shell M/platinum (Pt) catalysts (where M can be nickel, cobalt, or iron). We report on a class of platinum-lead/platinum (PtPb/Pt) core/shell nanoplate catalysts that exhibit large biaxial strains. The stable Pt (110) facets of the nanoplates have high ORR specific and mass activities that reach 7.8 milliampere (mA) per centimeter squared and 4.3 ampere per milligram of platinum at 0.9 volts versus the reversible hydrogen electrode (RHE), respectively. Density functional theory calculations reveal that the edge-Pt and top (bottom)–Pt (110) facets undergo large tensile strains that help optimize the Pt-O bond strength. The intermetallic core and uniform four layers of Pt shell of the PtPb/Pt nanoplates appear to underlie the high endurance of these catalysts, which can undergo 50,000 voltage cycles with negligible activity decay and no apparent structure and composition changes.

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Jianniao Tian

Papers

Enhanced electrocatalytic oxidation of methanol on Pd/polypyrrole-graphene in alkaline medium

Methanol electro-oxidation on Ni@Pd core-shell nanoparticles supported on multi-walled carbon nanotubes in alkaline media

Probing the Binding of Scutellarin to Human Serum Albumin by Circular Dichroism, Fluorescence Spectroscopy, FTIR, and Molecular Modeling Method

Interaction of wogonin with bovine serum albumin.

Study of the interaction of kaempferol with bovine serum albumin