조은선 교수

Interest in hydrogen fuel is growing for automotive applications; however, safe, dense, solid-state hydrogen storage remains a formidable scientific challenge. Metal hydrides offer ample storage capacity and do not require cryogens or exceedingly high pressures for operation. However, hydrides have largely been abandoned because of oxidative instability and sluggish kinetics. We report a new, environmentally stable hydrogen storage material constructed of Mg nanocrystals encapsulated by atomical

Abstract Demand for pragmatic alternatives to carbon‐intensive fossil fuels is growing more strident. Hydrogen represents an ideal zero‐carbon clean energy carrier with high energy density. For hydrogen fuel to compete with alternatives, safe and high capacity storage materials that are readily cycled are imperative. Here, development of such a material, comprised of nickel‐doped Mg nanocrystals encapsulated by molecular‐sieving reduced graphene oxide (rGO) layers, is reported. While most work o

Abstract Ordered mesoporous carbon materials offer robust network of organized pores for energy storage and catalysis applications, but suffer from time‐consuming and intricate preparations hindering their widespread use. Here we report a new and rapid synthetic route for a N‐doped ordered mesoporous carbon structure through a preferential heating of iron oxide nanoparticles by microwaves. A nanoporous covalent organic polymer is first formed in situ covering the hard templates of assembled nano

Reverse electrodialysis (RED) directly harvests renewable energy from salinity gradients, and the achievable potential power heavily relies on the ion exchange membranes. Graphene oxides (GOs) are considered a solid candidate for the RED membrane because the laminated GO nanochannels with charged functional groups provide an excellent ionic selectivity and conductivity. Yet, a high internal resistance and poor stability in aqueous solutions limit the RED performance. Here, we develop a RED membr

Nanoencapsulation using graphene derivatives enables the facile fabrication of two-dimensional (2D) nanocomposites with unique microstructures and has been generally applied to many fields of energy materials. Particularly, metal hydrides such as MgH₂ encapsulated by graphene derivatives have emerged as a promising hybrid material for overcoming the disadvantageous properties of Mg-based hydrogen storage. Although the behavior of the graphene-Mg nanoencapsulation interface has been st

With global efforts to relieve the formidable impact of climate change, hydrogen is considered a viable replacement for fossil fuels without intermittency concerns of other renewable sources. Hydrogen storage plays a pivotal role in the implementation of hydrogen economy, coupling hydrogen production with fuel cell technologies. Storing hydrogen in the form of solid-state hydride materials has been studied as a future hydrogen storage technology for enabling a safe, energy-efficient, and high-en

A general problem when designing functional nanomaterials for energy storage is the lack of control over the stability and reactivity of metastable phases. Using the high-capacity hydrogen storage candidate LiAlH₄ as an exemplar, we demonstrate an alternative approach to the thermodynamic stabilization of metastable metal hydrides by coordination to nitrogen binding sites within the nanopores of N-doped CMK-3 carbon (NCMK-3). The resulting LiAlH₄@NCMK-3 material releases H<

The roles of graphene oxide scaffolds in the nucleation and growth of Mg nanocrystals and the consequent hydrogen storage properties are revealed. This work lays the foundation for design guidelines towards more optimized hydrogen storage composites.

An emerging class of materials that are hybrid in nature is propelling a technological revolution in energy, touching many fundamental aspects of energy-generation, storage, and conservation. Hybrid materials combine classical inorganic and organic components to yield materials that manifest new functionalities unattainable in traditional composites or other related multicomponent materials, which have additive function only. This Research News article highlights the exciting materials design in

Hydrogen is a long-term clean energy carrier that enables completely carbon-free energy production. However, practical implementation of hydrogen fuel technologies is restricted because of lack of safe and high-performing storage materials. Here, we report Mg nanocrystals encapsulated by narrow, bottom-up synthesized graphene nanoribbons (GNRs) as environmentally stable and high-capacity hydrogen storage materials. As an encapsulation medium, GNRs offer similar functionalities as reduced graphen

Abstract A new pH sensor based on carbon nanotubes (CNTs), which consist of a fluorescent molecule and a CNT attached to each chain end of a pH sensitive polysulfonamide, respectively, is synthesized, and its pH sensitivity is examined in terms of the fluorescent quenching efficiency of the CNT. The pH sensitive polymeric linker shows an abrupt conformational change between an expanded coil structure and a collapsed globule structure, which results in the drastic on‐and‐off fluorescent quenching

Hydrogen is regarded as an attractive substitute for fossil fuel, but stable and safe storage of hydrogen remains a formidable challenge. In this work, a nanometer-thickness Mg nanosheet is synthesized in a one-pot system for the first time and it enables expedited hydrogen sorption through its large surface area and shortened transport paths. The Mg nanosheets absorb about 6 wt % hydrogen within 1 h without any catalyst. Also, it is demonstrated that upon adding one-dimensional carbon materials

Selective bond cleavage using a photoredox reaction is a powerful technique in the chemical conversion of biomass such as lignin since it enables us to produce value-added aromatic compounds by controlling the activation of certain chemical bonds. Also, a water-based environment would be preferred for the sake of an eco-friendly reaction, additionally having the advantage of utilizing water-originated species such as • OH and H 2 O 2 . However, a direct cleavage of the C–C bond is still challeng