TY - JOUR
T1 - Effects of electrolyte concentration and anion identity on photoelectrochemical degradation of phenol
T2 - Focusing on the change at the photoanode/solution interface
AU - Lee, Yonghyeon
AU - Khim, Jeehyeong
N1 - Funding Information:
This work was supported by the Basic Science Research Program through a National Research Foundation of Korea (NRF) grant funded by the Korea government (No. 2019R1A2C2087439 ).
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/12
Y1 - 2021/12
N2 - The effects of electrolytes on phenol degradation by typical photoelectrochemical cell (PEC) composed of TiO2-nanotube array (TNTA) and Pt were studied in terms of interfacial parameters; quantum efficiency, h+ generation rate, relative interfacial electron transfer rate, and equivalent resistances. Three different anions, Cl−, ClO4−, and SO42−, and 10−5 to 10−1 M of electrolyte concentrations have been covered. For all concentrations of interest, pseudo-1st-order kinetic constants for phenol degradation were 4.775 × 10−4–1.175 × 10−3, 3.974 × 10−4–8.893 × 10−3, and 3.902 × 10−4–8.810 × 10−4 min−1 for SO42−, Cl−, and ClO4−, respectively. The results of h+-generation rate, and relative electron transfer rate confirms that the rate of reactions at electrode/solution interface is in the order of SO42−, ClO4−, and Cl−; 0.038–3.552%, 0.023–2.900%, and 0.021–2.814% were obtained for the quantum efficiency of SO42−, ClO4−, and Cl−, respectively. The inconsistent trend between phenol degradation kinetic and quantum efficiency in terms of anion species shows that the phenol is mainly decomposed by the oxidant produced through the interfacial reactions, not by direct reaction between TiO2 and phenol. The difference in terms of anions would be attributed to the product of anions since the radicals other than hydroxyl radical would provide the retardation pathways to prolong the lifetime of radicals.
AB - The effects of electrolytes on phenol degradation by typical photoelectrochemical cell (PEC) composed of TiO2-nanotube array (TNTA) and Pt were studied in terms of interfacial parameters; quantum efficiency, h+ generation rate, relative interfacial electron transfer rate, and equivalent resistances. Three different anions, Cl−, ClO4−, and SO42−, and 10−5 to 10−1 M of electrolyte concentrations have been covered. For all concentrations of interest, pseudo-1st-order kinetic constants for phenol degradation were 4.775 × 10−4–1.175 × 10−3, 3.974 × 10−4–8.893 × 10−3, and 3.902 × 10−4–8.810 × 10−4 min−1 for SO42−, Cl−, and ClO4−, respectively. The results of h+-generation rate, and relative electron transfer rate confirms that the rate of reactions at electrode/solution interface is in the order of SO42−, ClO4−, and Cl−; 0.038–3.552%, 0.023–2.900%, and 0.021–2.814% were obtained for the quantum efficiency of SO42−, ClO4−, and Cl−, respectively. The inconsistent trend between phenol degradation kinetic and quantum efficiency in terms of anion species shows that the phenol is mainly decomposed by the oxidant produced through the interfacial reactions, not by direct reaction between TiO2 and phenol. The difference in terms of anions would be attributed to the product of anions since the radicals other than hydroxyl radical would provide the retardation pathways to prolong the lifetime of radicals.
KW - Anion effects
KW - Electron-hole pair generation rate
KW - Interfacial electron transfer rate
KW - Photoelectrocatalysis
KW - Quantum efficiency
UR - http://www.scopus.com/inward/record.url?scp=85119279060&partnerID=8YFLogxK
U2 - 10.1016/j.jece.2021.106717
DO - 10.1016/j.jece.2021.106717
M3 - Article
AN - SCOPUS:85119279060
SN - 2213-2929
VL - 9
JO - Journal of Environmental Chemical Engineering
JF - Journal of Environmental Chemical Engineering
IS - 6
M1 - 106717
ER -