Sang Ouk Kim

Abstract Miniaturization of electronics demands electromagnetic interference (EMI) shielding of nanoscale dimension. The authors report a systematic exploration of EMI shielding behavior of 2D Ti 3 C 2 T x MXene assembled films over a broad range of film thicknesses, monolayer by monolayer. Theoretical models are used to explain the shielding mechanism below skin depth, where multiple reflection becomes significant, along with the surface reflection and bulk absorption of electromagnetic radiati

Cost effective hydrogen evolution reaction (HER) catalyst without using precious metallic elements is a crucial demand for environment-benign energy production. Molybdenum sulfide is one of the promising candidates for such purpose, particularly in acidic condition, but its catalytic performance is inherently limited by the sparse catalytic edge sites and poor electrical conductivity. We report synthesis and HER catalysis of hybrid catalysts composed of amorphous molybdenum sulfide (MoSx) layer

Crystal clear: The liquid crystallinity of graphene oxide platelets in aqueous dispersion is demonstrated. Graphene oxide sheets are arranged around liquid-crystal disclinations (see picture). The orientation of the liquid crystals can be manipulated by a magnetic field or mechanical deformation. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by th

Stable dispersion of reduced graphene in various organic solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aqueous dispersion of reduced graphene was prepared by chemical reduction of graphene oxide in aqueous media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a solubility test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polys

Outstanding pristine properties of carbon nanotubes and graphene have limited the scope for real-life applications without precise controllability of the material structures and properties. This invited article to celebrate the 25th anniversary of Advanced Materials reviews the current research status in the chemical modification/doping of carbon nanotubes and graphene and their relevant applications with optimized structures and properties. A broad aspect of specific correlations between chemic

Substitutional heteroatom doping is a promising route to modulate the outstanding material properties of carbon nanotubes and graphene for customized applications. Recently, (nitrogen-) N-doping has been introduced to ensure tunable work-function, enhanced n-type carrier concentration, diminished surface energy, and manageable polarization. Along with the promising assessment of N-doping effects, research on the N-doped carbon based composite structures is emerging for the synergistic integratio

Hey ho, let's GO: Graphene oxide platelets can be self-assembled into highly ordered, mechanically flexible carbon films with tunable porous morphologies. Further nitrogen doping enhanced the electrical properties and supercapacitor performances of the carbon-based assemblies, and provided chemical functionalization. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made availab

Site specific electroless gelation enables straightforward solution processing of graphene gel films with ultimate scalability and three-dimensional shape engineering. Due to the synergistic combination of open porous structure and highly electro-conductivity graphene gel framework, shape engineered gel films could be exploited for high performance supercapacitor electrode and achieved large energy capacity and high power density, simultaneously. As a service to our authors and readers, this jou

Two-dimensional (2D) MXene has shown enormous potential in scientific fields, including energy storage and electromagnetic interference (EMI) shielding. Unfortunately, MXene-based material structures generally suffer from mechanical fragility and vulnerability to oxidation. Herein, mussel-inspired dopamine successfully addresses those weaknesses by improving interflake interaction and ordering in MXene assembled films. Dopamine undergoes in situ polymerization and binding at MXene flake surfaces

Graphene is a promising candidate to complement brittle and expensive transparent conducting oxides. Nevertheless, previous research efforts have paid little attention to reduced graphene, which can be of great benefit due to low-cost solution processing without substrate transfer. Here we demonstrate workfunction-tunable, highly conductive, N-doped reduced graphene film, which is obtainable from the spin-casting of graphene oxide dispersion and can be successfully employed as a transparent cath

A hybrid system with vertical carbon nanotubes (CNTs) grown on reduced graphene films composed of overlapping and reduced graphene oxide platelets is reported. Such carbon hybrid films have excellent flexibility and stretchability (see image), can be readily transferred to any substrate including nonplanar surfaces, and were found to have Ohmic electrical contacts throughout all junctions in the CNT/metal-catalyst/graphene-film system. Detailed facts of importance to specialist readers are publi

Directed self-assembly of block copolymers has received a great deal of research attention as a promising nanolithography to complement the intrinsic limitations of conventional photolithography. In this review, we highlight the recent progress in the development of the directed self-assembly process for practical utilization in semiconductor applications. Various advanced directed self-assembly approaches are examined, in which block copolymer self-assembly is synergistically integrated with co

Abstract Bifunctional catalysts can facilitate two different electrochemical reactions with conflicting characteristics. Here, a highly reversible bifunctional electrocatalyst for rechargeable zinc–air batteries (ZABs) is reported featuring a “core–shell structure” in which N‐doped graphene sheets wrap around vanadium molybdenum oxynitride nanoparticles. Single Mo atoms are released from the particle core during synthesis and anchored to electronegative N‐dopant species in the graphitic shell. T

Doping improves performance. N- or B-doped carbon nanotubes (CNTs) uniformly dispersed in the active layer of P3HT/PCMB (poly (3-hexylthiophene/[6,6]-phenyl-C61-butyric acid methyl ester) bulk-heterojunction solar cells selectively enhance electron or hole transport and eventually help carrier collection. Specifically, the incorporation of 1.0 wt% B-doped CNTs results in balanced electron and hole transport and accomplishes a power conversion efficiency improvement from 3.0% (without CNTs) to 4.