Graphene: a new emerging lubricant

In recent years, reducing friction and wear-related mechanical failures in moving mechanical systems has gained increased attention due to friction's adverse impacts on efficiency, durability, and environmental compatibility. Accordingly, the search continues for novel materials, coatings, and lubricants (both liquid and solid) that can potentially reduce friction and wear. Despite intense R&D efforts on graphene for a myriad of existing and future applications, its tribological potential as a lubricant remains relatively unexplored. In this review, we provide an up-to-date survey of recent tribological studies based on graphene from the nano-scale to macro-scale, in particular, its use as a self-lubricating solid or as an additive for lubricating oils.