TY - JOUR
T1 - Persulfate activation by nanodiamond-derived carbon onions
T2 - Effect of phase transformation of the inner diamond core on reaction kinetics and mechanisms
AU - Yang, Bowen
AU - Kang, Haisu
AU - Ko, Young Jin
AU - Woo, Heesoo
AU - Gim, Geondu
AU - Choi, Jaemin
AU - Kim, Jaesung
AU - Cho, Kangwoo
AU - Kim, Eun Ju
AU - Lee, Seung Geol
AU - Lee, Hongshin
AU - Lee, Jaesang
N1 - Funding Information:
This study was supported by a National Research Foundation of Korea grant funded by the Korean government (MSIP) [grant no. NRF-2018R1A4A1022194 ] and the National Research Foundation of Korea grant funded by the Ministry of Science, ICT, and Future Planning [grant No. 2016M3A7B4909318 ].
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/9/15
Y1 - 2021/9/15
N2 - To investigate the impact of carbon phase conversion on the catalytic activity of nanodiamonds, in this study, we tested nanodiamonds subjected to graphitization at varying temperatures for persulfate activation. Temperatures beyond 1000°C (where only surface graphitization occurs) steadily enhanced the persulfate activation capability as the inner carbon underwent substantial sp3-to-sp2 transformation. Nanodiamonds annealed at 2000°C outperformed benchmark nanocarbons in terms of persulfate activation efficiency. Non-radical activation occurred primarily based on the effects of radical quenchers, oxidation product distribution, substrate-dependent reactivity, and electron paramagnetic resonance spectra. Aligned with the density functional theory calculations of the binding energies of peroxydisulfate on the slab models, built via Bernal stacking of graphitic carbon layers on the diamond plane, isothermal titration calorimetry measurements suggested that the binding affinity of peroxydisulfate decreased as the sp2/sp3 ratio increased. Therefore, the enhancing effect of graphitization arose from the electrical conductivity of nanodiamonds, which increased proportionally with graphitization extent.
AB - To investigate the impact of carbon phase conversion on the catalytic activity of nanodiamonds, in this study, we tested nanodiamonds subjected to graphitization at varying temperatures for persulfate activation. Temperatures beyond 1000°C (where only surface graphitization occurs) steadily enhanced the persulfate activation capability as the inner carbon underwent substantial sp3-to-sp2 transformation. Nanodiamonds annealed at 2000°C outperformed benchmark nanocarbons in terms of persulfate activation efficiency. Non-radical activation occurred primarily based on the effects of radical quenchers, oxidation product distribution, substrate-dependent reactivity, and electron paramagnetic resonance spectra. Aligned with the density functional theory calculations of the binding energies of peroxydisulfate on the slab models, built via Bernal stacking of graphitic carbon layers on the diamond plane, isothermal titration calorimetry measurements suggested that the binding affinity of peroxydisulfate decreased as the sp2/sp3 ratio increased. Therefore, the enhancing effect of graphitization arose from the electrical conductivity of nanodiamonds, which increased proportionally with graphitization extent.
KW - Electron transfer-mediating capacity
KW - Graphitized nanodiamonds
KW - Non-radical mechanism
KW - Peroxydisulfate activation
KW - Surface affinity
UR - http://www.scopus.com/inward/record.url?scp=85104486446&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2021.120205
DO - 10.1016/j.apcatb.2021.120205
M3 - Article
AN - SCOPUS:85104486446
SN - 0926-3373
VL - 293
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 120205
ER -