Understanding the high chemi-catalytic reactivity of graphene quantum dots to rapidly generate reactive oxygen species

Abstract

Graphene quantum dots (GQDs) have garnered favorable consideration as an advanced metal-free base material for generating reactive oxygen species (ROS). Recently, it is of great interest to develop new catalytic reactions for the GQDs. However, a rapid and simultaneous generation of large amounts of multiple ROS through GQDs is still challenging. Herein, we firstly prepare N-GQDs (nitrogen-doped GQDs) with abundant irregular structure defects and rich reactive functional groups (CO, CO, OCO, and CN) in a mechanochemical method, which can simultaneously generate a large number of ROS including 1O2, O2−, and OH in the presence of in the presence of acid (either inorganic or organic acid) without oxygen in dark. At the same time, the N-GQDs were reduced to N-rGQDs (nitrogen-doped reduced GQDs) accompanied by CO2 release. The process and mechanism of ROS generation of the N-GQDs was extensively discussed. The obtained N-GQDs can efficiently catalyze the hydrothermal synthesis of MIL-101, a well-known metal-organic framework, which suggested the N-GQDs can be widely applied in different area to generate ROS.