Enhanced electrochemical oxidation of perfluorooctanoic acid on Ti/SnO2-Sb electrode by surface morphology regulation

Electrochemical oxidation is an effective method to degrade persistent organic pollutants. However, due to the limited catalytic activity of traditional thin film electrodes, the anodic oxidation process is slow and usually requires high energy consumption. Herein, Ti/SnO2-Sb electrode with regulated surface structure was reported to enhance the performance for electrochemical oxidation of persistent organic pollutants. The electrode deposited with SnO2-Sb nanoneedles (Ti/N-SnO2-Sb) showed higher oxidation activity. Its kinetic constant for perfluorooctanoic acid (PFOA) oxidation was 2.0 h−1 and the total organic carbon removal rate was 81.7% (4 h) at a relatively low current density of 6 mA/cm2. Compared with Ti/SnO2-Sb thin film and nanoparticles, Ti/N-SnO2-Sb significantly improved the electrochemical active area and •OH yield, and simultaneously reduced the electron transfer resistance, which enabled it to oxidize PFOA more rapidly even at a lower potential. This work provides a new strategy for promoting the electrochemical oxidation performance.