Electrospun aligned self-standing SnO2/Sb carbon nanofibrous anodic membrane for sulfamethoxazole electrocatalytic degradation

Recently, sulfamethoxazole (SMX) has become an emerging refractory antibiotic pollutant due to abuse and excessive use. In this study, self-standing PAN-based SnO2/Sb/CFs anodic membrane was fabricated by innovatively incorporating SnO2/Sb nanoparticles into carbon nanofibrous (CFs) membrane to treat the typical antibiotic, SMX. The significant sulfamethoxazole (SMX) degradation capacity by the SnO2/Sb/CFs nanofibrous anodic membrane was benefit from the excellent adsorption ability of CFs and the enhanced electrooxidation capacity by SnO2/Sb. In addition, the SnO2/Sb nanoparticles can further increase the oxygen evolution side reaction potential and improve conductivity. The flow-through nano-porous construction of SnO2/Sb/CFs membrane reactor can greatly improve the mass transfer rate and further enhance the degradation rate than the plate construction of conventional electrode. The anodic electrocatalysis on sulfamethoxazole (SMX) testing proven that, the optimal electrocatalytic conditions is at the 2.5 V applied potential, pH at 6, the degradation rate reached 67 % in 1 h at the initial SMX concentration of 10 mg/L. And non-toxic smaller intermediates of SMX were identified by LC-MS/MS, suggesting the refractory and highly toxic SMX was electrochemically degraded into small non-toxic molecules. The outstanding SMX electrochemical degradation performance and anodic carbon nanofibrous membrane stability indicated the SnO2/Sb/CFs anodic membrane has enormous potential to treat the refractory antibiotics from the wastewater.

Automated summary

In this study, a self-standing PAN-based SnO2/Sb/CFs anodic membrane was fabricated by incorporating SnO2/Sb nanoparticles into carbon nanofibrous (CFs) membrane to treat sulfamethoxazole (SMX), an emerging refractory antibiotic pollutant. The SnO2/Sb/CFs nanofibrous anodic membrane showed excellent SMX degradation capacity due to the adsorption ability of CFs and the enhanced electrooxidation capacity by SnO2/Sb. It also showed improved mass transfer rate and degradation performance compared to conventional plate electrodes.