Highly efficient electrochemical production of hydrogen peroxide over nitrogen and phosphorus dual-doped carbon nanosheet in alkaline medium

Abstract

• N/P co-doped carbon nanosheet was prepared by pyrolysis of chitosan-phytic acid complex hydrogels. • High ORR activity with selective H 2 O 2 production benefits from 2D nanostructure and N/P co-doping. • High H 2 O 2 production rate of 223.4 mmol g catayst −1 h −1 with faradaic efficiency of 80% was achieved in H-cell. Electrochemical two-electron oxygen reduction reaction (ORR) is a promising green method for hydrogen peroxide (H 2 O 2 ) production, but the H 2 O 2 selectivity and productivity in alkaline medium have remained too low for economic viability of the process. In the present work, we reported the design and preparation of nitrogen and phosphorus dual-doped carbon nanosheet (NPCNS) through direct pyrolysis of supramolecular aggregates that resulted from the cross-linking reaction between nitrogen bio-functional groups of chitosan and phosphoric groups of phytic acid. The resultant NPCNS catalysts exhibited very high electrochemical ORR activity and selectivity toward H 2 O 2 production in alkaline medium due to the unique 2D nanostructure and the synergistic effect between nitrogen and phosphorus dopant. High practical H 2 O 2 production rate of 223.4 mmol g catayst −1 h −1 with high faradaic efficiency of 80% could be also achieved in home-made H-cell, indicating the potential applications of H 2 O 2 in the waste water treatment, pulp and paper industry.