Unraveling the Role of F in Electrochemical Ozone Generation on the F-Doped PbO2 Electrode

Because of its metal-like conductivity, excellent catalytic activity, and acid resistance, lead dioxide (PbO 2 ) is the most used electrocatalyst for the practical electrochemical ozone production (EOP) technique. Introducing fluorine (F) into PbO 2 electrodes or electrolytes can significantly improve EOP activity. However, there is still lack of valid evidence on understanding the role of doping F in the PbO 2 electrode. In this work, we report a comprehensive study on the effect of F on EOP activity on electrochemically prepared PbO 2 electrodes. F doping suppresses the side reaction of dioxygen (O 2 ) evolution by inhibiting the formation of an α phase impurity of PbO 2 electrodes. The more hydrophobic surfaces by doping F promote O 2 adsorption as evidenced by low-temperature O 2 -temperature-programmed desorption experiments and thus are more favorable for ozone (O 3 ) generation. The in situ isotope labeling oxygen ( 18 O 2 ) experiment proves that at room temperature, O 2 can adsorb and dissociate on the operando PbO 2 electrode surface and participate in the formation of O 3 molecules. This work provides a comprehensive understanding of doping F for enhanced EOP.