Tailoring crystal facet microenvironments for simultaneous electrochemical ozone and hydrogen peroxide production

Developing a bifunctional electrocatalyst that can effectively produce O-3 and H2O2 is significant for the electrochemical synthesis of O-3 and H2O2 for the synergistic oxidative degradation of organic pollutants. In this study, SnO with various exposed facets was synthesized by tailoring the crystal facet microenvironment for oxygen intermediates adsorption for electrochemical ozone production (EOP) and two-electron oxygen reduction reaction (2e(-) ORR). The Faraday efficiency of SnO-1 with a high (110) facet ratio for O-3 was 22.0%, while SnO-4 with a high (002) facet ratio achieved a selectivity of 93.6% for H2O2. The theoretical calculation indicates that their excellent performances originated from the strong adsorption of the (110) facet on O* and O-2* and the suitable adsorption and desorption strength of the (002) facet on OOH*, respectively. This study provides an attractive strategy for the development of a bifunctional electrocatalyst for advanced electrochemical oxidation by tailoring the crystal facet microenvironment.