COF-assisted construction of steric mass-charge channels to boost activity for high-performance fuel cells.

The two-dimensional lamellar materials disperse platinum sites and minimize noble-metal usage for fuel cells, while mass transport resistance at the stacked layers spurs device failure with a significant performance decline in membrane electrode assembly (MEA). Herein, we implant porous and rigid sulfonated covalent organic frameworks (COF) into the graphene-based catalytic layer for the construction of steric mass-charge channels, which highly facilitates the activity of oxygen reduction reactions in both the rotating disk electrode (RDE) measurements and MEA device tests. Specifically, the normalized mass activity is remarkably boosted by 3.

Nitrogen-doped carbon nanotubes coated with zinc oxide nanoparticles as sulfur encapsulator for high-performance lithium/sulfur batteries.

Nitrogen-doped carbon nanotubes coated with zinc oxide nanoparticles (ZnO@NCNT) were prepared via a sol-gel route as sulfur encapsulator for lithium/sulfur (Li/S) batteries. The electrochemical properties of the S/ZnO@NCNT composite cathode were evaluated in Li/S batteries. It delivered an initial capacity of 1032 mAh·g at a charge/discharge rate of 0.

Three-Dimensionally Hierarchical Graphene Based Aerogel Encapsulated Sulfur as Cathode for Lithium/Sulfur Batteries.

A simple and effective method was developed to obtain the electrode for lithium/sulfur (Li/S) batteries with high specific capacity and cycling durability via adopting an interconnected sulfur/activated carbon/graphene (reduced graphene oxide) aerogel (S/AC/GA) cathode architecture. The AC/GA composite with a well-defined interconnected conductive network was prepared by a reduction-induced self-assembly process, which allows for obtaining compact and porous structures. During this process, reduced graphene oxide (RGO) was formed, and due to the presence of oxygen-containing functional groups on its surface, it not only improves the electronic conductivity of the cathode but also effectively inhibits the polysulfides dissolution and shuttle.

Effects of mismatches and insertions on discrimination accuracy of nucleic acid probes.

Effective discrimination of non-complementary nucleotides is an important factor to ensure the accuracy of hybridization-based nucleic acid analyses. The current study investigates the effects of the chemical nature, the positions, the numbers, and the cooperative behavior of mismatches as well as insertions on 20-mer and 30-mer duplexes. We observed the hybridization stability trend affected by mismatches: G:T approximately G:G > G:A > A:A approximately T:T > A:C approximately T:C > C:C.