Giant graphene oxide (GGO) with radial size distribution of 30~70 μm is fabricated using the modified Hummers method, and graphene oxide ink is prepared. Through direct ink writing, the optimal printing parameters and patterning of graphene oxide ink are realized. When graphene oxide with a concentration of 15 mg/mL is printed at 70 kPa and 3 mm/s, the printing line is smooth and its morphology is fine and controllable. When the printing line is reduced by 15% hydroiodic acid for 3 h, its reduction degree is the highest and has the best electrical performance, with a conductivity up to 4.40×10⁴ S/m, which is much higher than that of the graphene patterned by the existing printing technology. Patterning of graphene oxide ink on various flexible and non-flexible substrates, such as PET, PDMS, glass and silicon wafers is alao successfully achieved. Reduced graphene oxide pattern can be used as a connecting conductor to realize the integration of LED, which is of great significance for the development of graphene based printed electronic devices.

graphene oxide ink  /  direct ink writing  /  printed electronics  /  patterning