title: Inherently-Forced Tensile Strain in Nanodiamond-Derived Onion-like Carbon: Consequences in Defect-Induced Electrochemical Activation.
abstract: We analyzed the nanodiamond-derived onion-like carbon (OLC) as function of synthesis temperature (1000~1400 °C), by high-resolution electron microscopy, electron energy loss spectroscopy, visible-Raman spectroscopy, ultraviolet photoemission spectroscopy, impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. The temperature dependences of the obtained properties (averaged particle size, tensile strain, defect density, density of states, electron transfer kinetics, and electrochemical oxidation current) unanimously coincided: they initially increased and saturated at 1200 °C. It was attributed to the inherent tensile strains arising from (1) the volume expansion associated with the layer-wise diamond-to-graphite transformation of the core, which caused forced dilation of the outer shells during their thermal synthesis; (2) the extreme curvature of the shells. The former origin was dominant over the latter at the outermost shell, of which the relevant evolution in defect density, DOS and electron transfer kinetics determined the electrochemical performances. In detection of dopamine (DA), uric acid (UA) and ascorbic acid (AA) using the OLC as electrode, their oxidation peak currents were enhanced by factors of 15~60 with annealing temperature. Their limit of detection and the linear range of detection, in the post-treatment-free condition, were as excellent as those of the nano-carbon electrodes post-treated by Pt-decoration, N-doping, plasma, or polymer.
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul 120-749, Republic of Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Ko
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul 120-749, Republic of Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Cho
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Inho
authors.initials: I
authors.lastname: Kim
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Doo Seok
authors.initials: DS
authors.lastname: Jeong
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Kyeong-Seok
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Jong-Keuk
authors.initials: JK
authors.lastname: Park
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Baik
authors.affiliation: Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul 120-749, Republic of Korea.
authors.forename: Heon-Jin
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Indo-Korea Science and Technology Center, Korea Institute of Science and Technology, Bangalore 560064, INDIA.
authors.forename: Seung-Cheol
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Center for Electronic Materials, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Wook-Seong
authors.initials: WS
authors.lastname: Lee