Oxygen Reduction Reaction for Generating H 2 O 2 through a Piezo‐Catalytic Process over Bismuth Oxychloride

Oxygen reduction reaction (ORR) for generating H 2 O 2 through green pathways have gained much attention in recent years. Herein, we introduce a piezo‐catalytic approach to obtain H 2 O 2 over bismuth oxychloride (BiOCl) through an ORR pathway. The piezoelectric response of BiOCl was directly characterized by piezoresponse force microscopy (PFM). The BiOCl exhibits efficient catalytic performance for generating H 2 O 2 (28 μmol h −1 ) only from O 2 and H 2 O, which is above the average level of H 2 O 2 produced by solar‐to‐chemical processes. A piezo‐catalytic mechanism was proposed: with ultrasonic waves, an alternating electric field will be generated over BiOCl, which can drive charge carriers (electrons) to interact with O 2 and H 2 O, then to form H 2 O 2 .