NBOH Site‐Activated Graphene Quantum Dots for Boosting Electrochemical Hydrogen Peroxide Production
Mengmeng Fan, Zeming Wang, Kang Sun, Ao Wang, Yuying Zhao, Qixin Yuan, Ruibin Wang, Jithu Raj, Jingjie Wu, Jianchun Jiang, Liang Wang
Abstract
Abstract Carbon materials are considered promising 2/4 e − oxygen reduction reaction (ORR) electrocatalysts for synthesizing H 2 O 2 /H 2 O via regulating heteroatom dopants and functionalization. Here, various doped and functionalized graphene quantum dots (GQDs) are designed to reveal the crucial active sites of carbon materials for ORR to produce H 2 O 2 . Density functional theory (DFT) calculations predict that the edge structure involving edge N, B dopant pairs and further OH functionalization to the B (NBOH) is an active center for 2e − ORR. To verify the above predication, GQDs with an enriched density of NBOH (NBO‐GQDs) are designed and synthesized by the hydrothermal reaction of NH 2 edge‐functionalized GQDs with H 3 BO 3 forming six‐member heterocycle containing the NBOH structure. When dispersed on conductive carbon substrates, the NBO‐GQDs show H 2 O 2 selectivity of over 90% at 0.7 –0.8 V versus reversible hydrogen electrode in the alkaline solution in a rotating ring‐disk electrode setup. The selectivity retains 90% of the initial value after 12 h stability test. In a flow cell setup, the H 2 O 2 production rate is up to 709 mmol g catalyst −1 h −1 , superior to most reported carbon‐ and metal‐based electrocatalysts. This work provides molecular insight into the design and formulation of highly efficient carbon‐based catalysts for sustainable H 2 O 2 production.