Fabrication of a SnO2-Sb nano-pin array anode for efficient electrocatalytic oxidation of bisphenol A in wastewater

Electrocatalytic oxidation is a promising technology for eliminating bio-recalcitrant organic pollutants; however, the low efficiency and poor durability of the anodes hinder its practical application. Herein, a SnO2-Sb nano-pin array (NPA) was fabricated on a RuO2-based dimensionally stable anode (DSA) via a new hydrothermal-electrodeposition route to prepare a novel anode (SnO2-Sb NPA). Compared with the conventional SnO2-Sb/DSA and SnO2-Sb/Ti anodes, the new SnO2-Sb NPA anode possessed twice the electroactive surface area and a higher electron transfer efficiency for electrocatalytic reactions. The SnO2-Sb NPA anode exhibited more than twice the rate constant of bisphenol A (BPA) degradation (0.026 min-1) and a 120 times prolonged service life in comparison to the conventional SnO2-Sb/Ti anode. Moreover, the SnO2-Sb NPA anode performed well in removing BPA from actual wastewater. The mechanism of electrocatalytic degradation involves direct oxidation via electron transfer through the nano-pin surface and oxidation by in situ generated •OH radicals.