title: Nanohole-Structured and Palladium-Embedded 3D Porous Graphene for Ultrahigh Hydrogen Storage and CO Oxidation Multifunctionalities.
abstract: Atomic-scale defects on carbon nanostructures have been considered as detrimental factors and critical problems to be eliminated in order to fully utilize their intrinsic material properties such as ultrahigh mechanical stiffness and electrical conductivity. However, defects that can be intentionally controlled through chemical and physical treatments are reasonably expected to bring benefits in various practical engineering applications such as desalination thin membranes, photochemical catalysts, and energy storage materials. Herein, we report a defect-engineered self-assembly procedure to produce a three-dimensionally nanohole-structured and palladium-embedded porous graphene hetero-nanostructure having ultrahigh hydrogen storage and CO oxidation multifunctionalities. Under multistep microwave reactions, agglomerated palladium nanoparticles having diameters of ∼10 nm produce physical nanoholes in the basal-plane structure of graphene sheets, while much smaller palladium nanoparticles are readily impregnated inside graphene layers and bonded on graphene surfaces. The present results show that the defect-engineered hetero-nanostructure has a ∼5.4 wt % hydrogen storage capacity under 7.5 MPa and CO oxidation catalytic activity at 190 °C. The defect-laden graphene can be highly functionalized for multipurpose applications such as molecule absorption, electrochemical energy storage, and catalytic activity, resulting in a pathway to nanoengineering based on underlying atomic scale and physical defects.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Oh
authors.forename: Hyun-Jun
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Jung
authors.forename: Chan-Ho
authors.initials: CH
authors.lastname: Jung
authors.affiliation: ∥Nano-Bio Electron Microscopy Research Group, Korea Basic Science Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea.
authors.forename: Won G
authors.initials: WG
authors.lastname: Hong
authors.affiliation: ∥Nano-Bio Electron Microscopy Research Group, Korea Basic Science Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea.
authors.forename: Hae-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jeong-Young
authors.initials: JY
authors.lastname: Park
authors.forename: Il-Kwon
authors.initials: IK
authors.lastname: Oh
keywords: CO oxidation; catalyst; defect-laden graphene; hydrogen storage; nanoholes