▎ 摘　　要

Graphene oxide (GO) and reduced graphene oxide (r-GO) continue to attract considerable research due to their applicability in many academic and industrial fields. Here, we report a liquid-phase plasma approach with fast reduction and high reactivity for directly converting GO to r-GO at mild temperatures. The liquid-phase plasma process is at the forefront, and it is a strong candidate for facilitating large-scale applications of GO and r-GO. In this work, using methanol as an additive rather than other hazardous reducing agents, the results demonstrated that methanol could provide more hydrogen radicals (center dot H) to improve the reduction process of the liquid-phase plasma. Meanwhile, the center dot CH2, center dot CH, center dot C, center dot C-2, center dot OH, center dot H, center dot O were formed during discharge, suggesting that the collision of energetic electrons in plasma with methanol and water, which subsequently removes oxygen-containing functional groups and restores the p-conjugated structure in GO through a radical process. The analytical results revealed that r-GO has been successfully reduced by liquid-phase plasma. In conclusion, our findings can provide underlying insights into liquid-phase plasma treatment for GO reduction.