Tribological properties of serpentine, La(OH)3 and their composite particles as lubricant additives

► We synthesized serpentine/La(OH)3 composite particles via sol-gel method. ► La(OH)3 nano-particles uniformly coat on the surface of serpentine particles. ► We test the tribological properties of La(OH)3, serpentine and their composite particles. ► The composite particles has the best friction-reducing, anti-wear and self-repairing properties. ► The lanthanum acted as catalyst to accelerate the reaction of the serpentine and the wear surface.