Convex polyhedral nanocrystals with high-index and low-index microfacets for electrochemical co-production of ozone and hydrogen peroxide

The co-production of electrochemical oxidation with ozone (O3) and hydrogen peroxide (H2O2) has emerged as a promising technology for degradation of organic pollutants, owing to more in situ-generated hydroxyl radicals. In this study, convex polyhedral Bi6PbnOx electrocatalysts were used in simultaneous electrochemical ozone production (EOP) and two-electron (2e−) oxygen reduction reaction (ORR) by tailoring microfaceting. The Bi6PbnOx demonstrated remarkable bifunctional electrocatalytic properties and stability, exhibiting high Faradaic efficiency of 15.3% for EOP and high selectivity of 92.8% for 2e− ORR. Theoretical calculation suggested that the high-index facet has good EOP performance due to the low oxygen vacancy formation, while the low-index facet has lower theoretical overpotential than other possible crystal facets, which played a crucial role in 2e− ORR. The results of the electrochemical degradation through the coupling reaction of O3 and H2O2 further demonstrated the potential environmental application capabilities of Bi6PbnOx bifunctional electrocatalysts.