Hanyang University

About: Hanyang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Population. The organization has 29387 authors who have published 58815 publications receiving 1190144 citations. The organization is also known as: Hanyang Taehakkyo.

Facile synthesis and the exploration of the zinc storage mechanism of β-MnO2 nanorods with exposed (101) planes as a novel cathode material for high performance eco-friendly zinc-ion batteries

Abstract: Aqueous Zn-ion batteries (ZIBs) have emerged as promising and eco-friendly next-generation energy storage systems to substitute lithium-ion batteries. Therefore, discovering new electrode materials for ZIBs with high performance and unraveling their electrochemical reactions during Zn-ion insertion/extraction are of great interest. Here, we present, for the first time, tunnel-type β-MnO2 nanorods with exposed (101) planes, prepared via a facile microwave-assisted hydrothermal synthesis within only 10 min, for use as a high performance cathode for ZIBs. In contrast to its bulk counterpart, which showed no electrochemical reactivity, the present β-MnO2 nanorod electrode exhibited a high discharge capacity of 270 mA h g−1 at 100 mA g−1, high rate capability (123 and 86 mA h g−1 at 528 and 1056 mA g−1, respectively), and long cycling stability (75% capacity retention with 100% coulombic efficiency at 200 mA g−1) over 200 cycles. The Zn-ion storage mechanism of the cathode was also unraveled using in situ synchrotron, ex situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy, and ex situ X-ray absorption spectroscopy. Our present study indicates that Zn intercalation occurred via a combination of solid solution and conversion reactions. During initial cycles, the β-MnO2 cathode was able to maintain its structure; however, after prolonged cycles, it transformed into a spinel structure. The present results challenge the common views on the β-MnO2 electrode and pave the way for the further development of ZIBs as cost-effective and environmentally friendly next-generation energy storage systems.

Indole-based macrocycles as a class of receptors for anions

Abstract: The development of synthetic receptors and chemosensors for anions has attracted much attention in recent years as the fundamental role of anions in biological and chemical processes has become increasingly understood. Biomacromolecules such as sulfate-binding proteins and a CIC chloride channel make use of hydrogen bonds as a major driving force to bind or transport anions through cell membranes. Similarly, hydrogen-bonding interactions are widely implemented for the construction of artificial receptors, and amido and ureido groups have frequently been incorporated for this purpose. 4] Furthermore, the pyrrolic NH group has also been used as a hydrogen-bond donor to an anion, as demonstrated in calixpyrroles, expanded porphyrinoids, and amidopyrroles. Herein, we describe the synthesis and binding properties of indole-based macrocycles 1 and 2, which can function as a new class of synthetic receptors for anions. The macrocycles contain a well-defined internal cavity surrounded by four indole NH hydrogen atoms, thus are capable of binding anions strongly through hydrogen-bonding interactions. More interestingly, 1 and 2 showed separate sets of H NMR signals for the free macrocycles and their complexes at room temperature in all cases and thus can serve as chemosensors for anions based on H NMR chemical shifts. The synthesis of 1 and 2 is outlined in Scheme 1. The key molecular building block 7,7’-diiodo-2,2’-biindole (4) was prepared by oxidative dimerization (Cu(OAc)2, 95%) [9]

In vivo high-throughput profiling of CRISPR-Cpf1 activity

Abstract: A lentiviral library expressing Cpf1 guide RNAs and containing target sequences allows high-throughput profiling of highly active guide RNAs and is the basis for cindel, a webtool to predict the activity at any given target sequence.