Synchronous generation of green oxidants H2O2 and O3 by using a heterojunction bifunctional ZnO/ZnS@C electrocatalyst

H2O2 and O3 production through electrochemical synthesis is a promising approach to replace anthraquinone processes and corona discharge. However, the simultaneous generation of H2O2 and O3 and the use of their synergistic oxidation to degrade organic contaminants remains a challenge. Herein, heterojunction bifunctional ZnO/ZnS@C electrocatalysts were prepared by a one-step pyrolysis method. ZnO/ZnS@C-750 can achieve 90% selectivity for H2O2 and 11% Faraday efficiency for gaseous O3. The primary contributor to such a performance was exploited to accelerate the electron transfer on the heterogeneous interface and generate more reaction sites. H2O2 and O3 can also be simultaneously generated in the electrolyzer and the synergistic effect of H2O2 and O3 can be utilized to completely degrade organic pollutants, such as phenol and tetracycline. This work provided new insights into the design of the 2e− ORR (oxygen reduction reaction) and EOP (electrochemical ozone production) bifunctional electrocatalysts for pollutant degradation.