Ultrasonic-electrodeposition construction of high hydrophobic Ce-PDMS-PbO2/SS electrode for p-nitrophenol degradation: Catalytic, kinetics and mechanism

Abstract

In this work, a novel hydrophobic microsphere Ce-PDMS-PbO2 structure on stainless steel (SS) was prepared via ultrasonic-electrodeposition as an efficient anodic electrocatalyst for p-nitrophenol (PNP) degradation. Compared to PbO2/SS, such Ce-PDMS-PbO2/SS electrode exhibits obviously lower activation energy (19.20 kJ mol−1) and charge transfer resistance (3.268 Ω cm−2), tolerable stability, higher exchange current density (1.171 ×10−5 A cm−2) and electrochemical active area (202.0 cm2). The as-synthesized Ce-PDMS-PbO2/SS anode achieved drastically enhanced PNP removal efficiency of 96.9% in 120 min, and the degradation reaction-order was calculated to be 0.9123 conformed to the quasi-first-order reaction kinetics. The GC-MS results reveal the possible PNP degradation pathway under the action of both anodic and cathodic reactions. Furthermore, the DFT calculation results show that Ce doping can decrease the activation energy barrier of ·OH and promote the ·OH generation. Overall, this work offers a new strategy and comprehension to construct a high-efficiency electrode for PNP pollutants degradation.