In this study, Sb doped SnO2/carbon nanotube (Sb-SnO2/CNT (SS/CNT)), Ni-Sb-SnO2/CNT (Ni-SS/CNT), Co-Sb-SnO2/CNT (Co-SS/CNT) and Fe-Sb-SnO2/CNT (Fe-SS/CNT) filters were fabricated on the surfaces of CNTS via electrosorption using Sb-SnO2 with the co-dopants Ni, Co, or Fe, which are widely used as electrocatalysts. The electrochemical activities of the CNT and modified CNT filters were compared by investigating the adsorption and decomposition of phenol, and oxidation of ferrocyanide. The CNT filter and modified filters respectively exhibited 8.05% and 5.02% ~ 6.67% phenol adsorption. However, phenol decomposition increased by approximately 1.50- and 1.64-fold over the Fe-SS/CNT and Ni-SS/CNT filters compared that over the CNT filter, respectively, indicating that the electrochemical activity was increased via metal doping (Fe, Ni) of the CNT surface. Among the modified CNT filters, the Fe-SS/CNT filter displayed higher levels of phenol-based total organic carbon removal and current efficiency (19.2% and 14.9%, respectively) than those of the other CNT filters, and it exhibited the fastest ferrocyanide oxidation.