Synthesis of thermally reduced graphite oxide in sulfuric acid and its application as an efficient lubrication additive

Graphene as an efficient lubrication additive attracts more and more attentions. The structure and the properties of graphene are influenced by its synthesis process. Although thermal reduction of graphene is an excellent method, such graphene always has some defects including obvious fold and wrinkling. In this study, a new synthesis method of thermally reduced graphite oxide in sulfuric acid (SA-tRGO) is proposed for preparing a graphene additive, and it shows a lamellar structure without obvious fold and wrinkling. The SA-tRGO shows outstanding tribological properties, and even at a high load (1.86 GPa) the friction coefficient and the wear rate still can be decreased by 30% and 75%, respectively. The synthesis method is simple and has great industrialization potential. •A new synthesis method of thermally reduced graphite oxide in sulfuric acid (SA-tRGO) is proposed.•SA-tRGO has a lamellar structure without obvious fold and wrinkling.•SA-tRGO-based lubricant shows outstanding tribological properties.•The method is simple and efficient, and thus has great potential of industrialization.