Preparation of Ti/SnO2-Sb electrodes modified by carbon nanotube for anodic oxidation of dye wastewater and combination with nanofiltration

• Ti/SnO2-Sb-CNT electrodes were prepared by pulse electrodeposition technology.
• The characteristics of Ti/SnO2-Sb-CNT was compared with Ti/SnO2-Sb.
• We combined electro-catalytic oxidation with NF to treat dye wastewater.

A new type of Ti/SnO2-Sb electrode modified with carbon nanotube (CNT) has been fabricated using a pulse electrodeposition method. The electrode modified with CNT versus without CNT has larger surface area and smaller crystallite particles (41.9 nm versus 46.8 nm) as seen by scanning electron microscopy (SEM), and calculated through X-ray diffraction (XRD), respectively. It means that the CNT-modified electrode can provide more active sites for electrochemical oxidation of organic pollutants. Oxygen evolution potential of the CNT-modified electrode has 0.07 V higher overpotential in the Linear sweep voltammetry (LSV) curve. The service lifetime of Ti/SnO2-Sb-CNT electrode is 4.8 times longer than that of the Ti/SnO2-Sb electrode without CNT modifying. The Ti/SnO2-Sb-CNT electrode is demonstrated to have a superior electrochemical oxidation and degradation abilities using Acid Red 73 (AR 73) as a model organic pollutant. The CNT-modified electrode has higher kinetic rate constant, chemical oxygen demand (COD) and total organic carbon (TOC) removals, and mineralization current efficiency, which is 1.93, 1.27, 1.26, and 1.38 times those of the Ti/SnO2-Sb electrode, respectively. The repeated experiments prove the reproducibility of the data. Ti/SnO2-Sb-CNT electrode is 1.15 times more effective in permeation flux than the Ti/SnO2-Sb electrode when combining electro-catalytic oxidation and nanofiltration for treating dye wastewater.