Unique synergistic effects of ternary multi-dimensional CNT/g-C3N4/MoS2 hybrid as a paraffin oil additive for improved tribological properties

Graphitic carbon nitride (g-C 3 N 4 ) nanomaterials have drawn much interest in the lubrication and friction fields owing to their excellent self-lubrication and mechanical performances. However, the easy agglomeration and poor dispersion stability of single g-C 3 N 4 (CN) have always been a headache. In the work, multi-dimensional ternary carbon nanotube, graphite carbon nitride, and molybdenum disulfide (CNT, CN, and MoS 2 ) hybrids were fabricated by hydrothermal method. The microstructure and its reinforcement impact on the tribological properties of the corresponding paraffin oil were systematically studied. The results showed that the zero-dimensional spherical MoS 2 , one-dimensional tubular CNT, and two-dimensional lamellar CN are uniformly compounded. The tribological test results display that average friction coefficient and wear rate of the 0.2   wt% CNT/CN/MoS 2 are decreased by 39.23% and 91.97% lower than those of pure paraffin oil, CNT and CN/MoS 2 with the same concentration, respectively. The significantly improved tribological properties of lubricating oil is ascribed to even dispersion of CNT, CN, MoS 2 in CNT/CN/MoS 2 hybrids, self-lubricating effect of MoS 2 and CN, and load-bearing ability of CNT and CN nanosheets, and also the generation of lubricating film between friction pairs during the wear process.