<p>The oxidation degree is the main challenge for any specific application of GO. This study aims to develop fully oxidized and non-overoxidized two-dimensional nano-graphene oxide (nano-GO) with a larger specific surface area under relatively safe and less polluting reaction conditions. An improved Hummers’ method was employed to prepare nano-GO, which involved in lowering the oxidation temperature and extending the oxidation time. The phase structure, defect degree, basal plane structure, functional group, micromorphology and surface microstructure of nano-GO were characterized, revealing that nano-GO has been successfully prepared. The results revealed that the prepared nano-GO exhibited enhanced crystallinity, purity, and a preferred growth orientation along the (001) crystal plane. The oxidation process led to the formation of oxygen-containing functional groups, which were more concentrated at the edges of lamellar structure, resulting in increased surface roughness. The prepared nano-GO achieved a certain oxidation degree while maintaining better physical stability and a lower degree of grain defects. This study provides a foundation for the research, discussion, and reference of carbon nanomaterials and paves the way for investigations into ultra-high performance composite materials.</p>