TY - JOUR
T1 - Oxidation of organic pollutants by peroxymonosulfate activated with low-temperature-modified nanodiamonds
T2 - Understanding the reaction kinetics and mechanism
AU - Yun, Eun Tae
AU - Moon, Gun Hee
AU - Lee, Hongshin
AU - Jeon, Tae Hwa
AU - Lee, Changha
AU - Choi, Wonyong
AU - Lee, Jaesang
N1 - Funding Information:
This study was supported by the Basic Science Research Program ( NRF-2017R1A2B4002235 ) and a grant from the National Research Foundation of Korea , funded by the Ministry of Science, ICT, and Future Planning (No. 2016M3A7B4909318 );
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/12/5
Y1 - 2018/12/5
N2 - Changes in surface carbon hybridization through high-temperature annealing (>1000 °C) of nanodiamond (ND), i.e., surface graphitization, enable peroxymonosulfate (PMS) activation by ND. Alternatively, this study suggests low-temperature surface modification (500 °C) of ND as an effective strategy for allowing ND to activate PMS. ND calcination in the presence of poly(diallydimethylammonium chloride) (PDDA) and graphene oxide (GO) in an NH3 atmosphere produced binary and ternary nitrogen-doped ND composites (i.e., N-ND/PDDA and N-ND/PDDA/GO). Compared with bare ND, theses surface-modified NDs markedly enhanced organic oxidation associated with PMS activation. In particular, N-ND/PDDA/GO outperformed graphitized ND in terms of PMS activation capacity. Spectroscopic characterization implied that the content of pyridinic N and the N doping level increased with further modification of ND. Oxidation by PMS activated with ND-based materials did not involve radical attack, as methanol did not exhibit a quenching effect, formaldehyde yield was insignificant, conversion of bromide into bromate was negligible, the substrate specificity contradicted sulfate radical (SO4[rad]−) reactivity, and no electron paramagnetic resonance spectral features were assignable to SO4[rad]− adducts. Impedance spectroscopic analysis indicated a high correlation between PMS activation efficacy and electrical conductivity. Chronoamperometric measurements showed that sequential injection of PMS and 4-chlorophenol caused current generation at electrodes coated with ND-based activators, and the increase in current intensity correlated well with PMS activation capacity. These findings suggest that ND-derived materials facilitated the electron transfer from organics to PMS, resulting in a degradative reaction route not reliant on radical species.
AB - Changes in surface carbon hybridization through high-temperature annealing (>1000 °C) of nanodiamond (ND), i.e., surface graphitization, enable peroxymonosulfate (PMS) activation by ND. Alternatively, this study suggests low-temperature surface modification (500 °C) of ND as an effective strategy for allowing ND to activate PMS. ND calcination in the presence of poly(diallydimethylammonium chloride) (PDDA) and graphene oxide (GO) in an NH3 atmosphere produced binary and ternary nitrogen-doped ND composites (i.e., N-ND/PDDA and N-ND/PDDA/GO). Compared with bare ND, theses surface-modified NDs markedly enhanced organic oxidation associated with PMS activation. In particular, N-ND/PDDA/GO outperformed graphitized ND in terms of PMS activation capacity. Spectroscopic characterization implied that the content of pyridinic N and the N doping level increased with further modification of ND. Oxidation by PMS activated with ND-based materials did not involve radical attack, as methanol did not exhibit a quenching effect, formaldehyde yield was insignificant, conversion of bromide into bromate was negligible, the substrate specificity contradicted sulfate radical (SO4[rad]−) reactivity, and no electron paramagnetic resonance spectral features were assignable to SO4[rad]− adducts. Impedance spectroscopic analysis indicated a high correlation between PMS activation efficacy and electrical conductivity. Chronoamperometric measurements showed that sequential injection of PMS and 4-chlorophenol caused current generation at electrodes coated with ND-based activators, and the increase in current intensity correlated well with PMS activation capacity. These findings suggest that ND-derived materials facilitated the electron transfer from organics to PMS, resulting in a degradative reaction route not reliant on radical species.
KW - Electron transfer
KW - Low-temperature modification
KW - Nanodiamond
KW - Non-radical mechanism
KW - Peroxymonosulfate activation
UR - http://www.scopus.com/inward/record.url?scp=85048265740&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2018.04.067
DO - 10.1016/j.apcatb.2018.04.067
M3 - Article
AN - SCOPUS:85048265740
VL - 237
SP - 432
EP - 441
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
ER -