Controlled synthesis of quasi-single-crystal lead dioxide by polyvinylpyrrolidone for enhanced electrochemical ozone production

Abstract

The crystal facet of PbO2 has been proved to be a key factor affecting its electrochemical ozone production (EOP) performance. However, PbO2 with smooth and uniform crystal surface and single-crystal nature, which is the basis and prerequisite for PbO2 crystal facet engineering, has not yet been reported. In this study, by adding polyvinylpyrrolidone (PVP) as a facet modifier during the hydrothermal synthesis, a quasi-single-crystal PbO2 (PVP:Pb(CH3COO)2·3H2O=48:100, PVP-48) with (110) and (101) exposed facets was successfully synthesized. Compared with commercial PbO2 prepared by electrochemical deposition, PVP-48 exhibits excellent electrochemical catalytic activity due to its special crystal structure, and achieves the highest current efficiency of 11.9 % at a current density of 0.83 A/cm2. Further calculations show that PVP prefers to adsorb onto the (110) facet of the lead dioxide and reduces its surface energy, thereby exposing the (110) facet more readily. This work demonstrates the importance of PbO2 facets composition and provides new ideas for further controllable synthesis of PbO2 with specific facet structure and higher EOP efficiency.