Ti/CoTiO3-TiO2 for Efficient Degradation of Refractory Organic Dyes: Synthesis, Characterization, and Electrocatalytic Properties

Abstract

A Ti/CoTiO3-TiO2 catalyst electrode was successfully prepared by a one-step impregnation pyrolysis method and systematically investigated through scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The electrochemical characterization results containing cyclic voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry further indicate that the as-prepared Ti/CoTiO3-TiO2 has higher oxygen evolution potential, lower resistance, higher electrochemical active surface area, and a longer lifetime than that of the pristine Ti/TiO2. A variety of dyes were selected as the target degraded pollutants for evaluating the electrocatalytic performance of Ti/CoTiO3-TiO2. Compared with those of the Ti/TiO2 and other counterparts, the Ti/CoTiO3-TiO2 shows significantly higher degradation efficiency, up to 98.5% under optimal conditions. Moreover, the Ti/CoTiO3-TiO2 displays superior stability and reusability. The higher electrochemical activity of Ti/CoTiO3-TiO2 than Ti/TiO2 may be the main reason for electrocatalytic performance enhancement, and the numerous ·OH and O2 − radicals generated on the anode surface may be the primary active species for dyes degradation. In addition, the possible degradation mechanism was inferred by analyzing the measured intermediates. Consequently, this work offers a strategy via constructing titanate composites to enhance the electrocatalytic degradation performance for the refractory organic pollutants.