Activation of peroxymonosulfate using metal-free in situ N-doped carbonized polypyrrole: A non-radical process.
Environ Res
; 193: 110537, 2021 02.
Article
em En
| MEDLINE
| ID: mdl-33264594
ABSTRACT
Metal-free catalysts are widely considered as promising alternatives to traditional metal-based catalysts, which can effectively activate peroxymonosulfate (PMS). In this study, a novel metal-free catalyst, carbonized polypyrrole (CPPy) was synthesized through high-temperature carbonization of PPy, easily achieving the in situ N doping without the addition of nitrogen sources. Tetracycline (TC) was selected as the target contaminant to assess the catalytic activity of the CPPy/PMS system. Enhanced catalytic activity was observed in CPPy/PMS over a wide pH range (3.0-9.0), and the removal rate of TC by CPPy-3/PMS reached 91.3% after 10 min. After regenerating the used catalyst, the catalytic activity was refreshed, implying its stability and recyclability. The catalytic degradation of TC by CPPy/PMS was mainly attributed to a non-radical process. CPPy, as an intermediary, grabbed electrons from the electron-donating groups of TC and transferred them to the PMS molecule. Thereafter, TC that lost electrons was oxidized and degraded, and the O-O bonds of PMS were destroyed by the transferred electrons to form SO42- and OH-. Moreover, Oâ
2- and 1O2 were involved in TC degradation. TC degradation pathway was investigated through HPLC-MS analysis. These findings provide a promising strategy for the construction of catalysts for PMS and environmental remediation.
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MEDLINE
Assunto principal:
Polímeros
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Pirróis
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article