Characterization and tribological properties of rice husk carbon nanoparticles Co-doped with sulfur and nitrogen

Abstract

A novel carbon nanoparticle co-doped with sulfur and nitrogen (S, NCN) was prepared from rice husk powder through a hydrothermal reaction. A series of modern analysis techniques was utilized to characterize the morphology, structure, and components of the S, NCN nanoparticles. Their tribological properties as a lubricating additive to polyethylene glycol (PEG200) base oil were investigated using a UMT-2 sliding tribometer. Results showed that the average diameter of nanoparticles were approximately 16 nm. The nanoparticles mainly included C, O, N, and S. The ID/IG value of S, NCN was 2.63. PEG200 that included different contents of S, NCN displayed remarkable lubricating performance compared with pure PEG200 under different loads (8, 20, 40, and 100 N). When 0.1 wt% S, NCN was dispersed in base oil, the friction coefficient and wear rate decreased by 16.6% and 75.9%, respectively. The friction and wear mechanisms were attributed to robust tribo-films that had developed as a result of tribo-chemical reactions induced by the S, NCN particles, comprising nitrides, sulfides, and metal oxides to promote wear resistance and friction reduction properties of PEG200.