Metal-free graphene-based catalyst-insight into the catalytic activity: A short review

摘要

For responding to the rapidly increasing trend of research on carbocatalyst, an emerging metal-free all carbon-based catalyst, we present here a timely short review article to summarize some relevant state-ofthe-art contributions, to find the bottleneck of the research in the current stage, and to offer a guideline for rational exploration and design of a high-performance graphene-based carbocatalyst for a specific catalytic reaction. Special emphasis is brought to the aspects of what make graphene-based carbocatalysts active for many kinds of synthetic transformations, such as reduction and oxidation reactions. Due to the importance of active species identification for graphene materials in the field of carbocatalysis, the possible active sites on the surfaces of graphene and its related materials are summarized and presented schematically as a general model, which can shed light on the mechanistic study on the catalytic performance of graphene-based carbocatalysts. Moreover, the difference between oxygenated graphene and reduced graphene oxide are specially reviewed and analyzed in terms of the relationship between their respective unique structures and catalytic performances. Finally, a conclusive model map is provided for combining the respective catalytic reaction models with the corresponding probable active sites on the surfaces of graphene-based carbocatalysts. The article presented here is expected to advance research on the biocompatible, sustainable, low-cost, scalable and green graphene-based carbocatalysts as promising alternatives to the metal-based catalysts that are being under excessive exploitation despite their scarcity, high cost and relative environmental unfriendliness, especially the noble metallic materials.