Transition metal single atom-optimized g-C3N4 for the highly selective electrosynthesis of H2O2 under neutral electrolytes†
Abstract
Neutral electrosynthesis of H2O2via the 2e− ORR is attractive for numerous applications, but the low activity and high cost of electrocatalysts have become important constraints. Therefore, the development of cheap and efficient electrocatalysts for the 2e− ORR is necessary. Herein, we report the embedding of transition metal single atoms (TM SAs) in g-C3N4 nanosheets (CNNS). The introduction of TM SAs increases the N–CN content and reduces the C–C/C
C content in CNNS, which contributes to the increased selectivity of TM SA/CNNS for the 2e− ORR. TM SA is the main reason for the enhanced activity of the 2e− ORR. Based on the results obtained by replacing a series of TM SA, the Ni0.10 SA/CNNS with optimal N–C
N content exhibited the best selectivity (∼98%) and highest yield of H2O2 (∼503 mmol gcat−1 h−1), which is ∼14.6 times higher than that of CNNS (∼34.4 mmol gcat−1 h−1). Other TM SA/CNNS also exhibited high activity and selectivity. This study demonstrates the ability of TM SA to modulate the selectivity and activity of CNNS, making it a promising candidate for the 2e− ORR and providing more reference ideas for the preparation of H2O2.