Preferential electrocatalytic degradation of 2,4-dichlorophenoxyacetic acid on molecular imprinted mesoporous SnO2 surface

Abstract

A molecular-imprinted mesoporous SnO2 electrode surface has been developed to achieve deep degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in complex coexisting system. Preferential electrocatalytic degradation of 2,4-D on our prepared electrode was observed in both the single component and coexisting system. The concentration of 2,4-D dropped down to 54 ppb after 6 h degradation in the coexisting sewage water system. The result reveals that our prepared electrode exhibited specific electrochemical recognition of target molecular 2,4-D. Besides, the mesoporous structure of SnO2 was proved to be great improvement of electrochemical activity with higher BET surface area (∼148.8 m2 g−1), electrochemical effective surface area (7.41 cm2 cm−2) and ·OH generation ability (66.5 μmol L−1) compared to conventional SnO2 electrode. However, the electrochemical activity influenced by the construction of MI sites was negligible. Furthermore, the preferential adsorption of 2,4-D on the surface of MI-meso SnO2 electrode was proved by both FT-IR spectra and chronocoulometry method.