▎ 摘　　要

Graphene has been widely used in novel optoelectronic devices in decades. Nowadays, fabrication of large size monolayer graphene with spectral selectivity is highly demanded. Here, we report a simple method for synthesizing large size monolayer graphene with chemical functionalized groups in solution. The few layer nano-graphene can be exfoliated into monolayer nano-graphene under short time UV irradiation in protic solution. The exfoliated monolayer nano-graphene could experience deoxygenation during long time UV exposure. At the same time, the edge of nano-graphene could be activated under deep UV exposure and small size nano-graphene sheets further aggregate horizontally in solution. The size of aggregated rGO increase from 40nm to a maximum of 1m. This approach could be one promising cheap method for synthesizing large size monolayer reduced graphene oxide in the future.