Superlubricity of carbon nanostructures

Superlubricity, a fantastic lubrication sate where friction or resistance to sliding nearly vanishes, has become one of the most important approaches to combat friction-induced energy consumption and devices failures. Emerging carbon nanostructures endow the research community with unprecedented opportunities to realize superlubricity across different length scales. This review provides an overview of the state-of-the-art of nanostructured carbon-based superlubricity, with a specific emphasis on unusual properties and new phenomena in representative carbon materials including layer carbon structure, diamond-like carbon, onion-like/fullerene-like carbons, ultra-nanocrystalline diamond and carbon nanotubes. The scientific fundamentals and technical routes to achieve superlow friction are highlighted for each individual carbon nanostructure. Perspectives on current challenges are put forward, and the possible future directions to guide the development of this field are suggested.