Enhancement of Triboactivity of Nanolamellar Graphitic-C3N4by N-Doped ZnO Nanorods

Abstract

The tribological activity of the synthesized nanosheets of a polymeric graphitic carbon nitride, g-C3N4, was upgraded by introducing hydrothermally synthesized N-doped zinc oxide nanorods. The high-resolution scanning electron microscopy, TEM, and HR-TEM studies of the hybrid (N-ZnO/g-C3N4) reveal that N-doped ZnO nanorods were spread over g-C3N4 nanosheets. The tribological activity of well-characterized nanomaterials was graded in paraffin oil (PO) at an optimized concentration, 0.20% w/v, on a four-ball tester conducting ASTM D4172 and ASTM D5183 tests. According to the observed tribological data, mean wear scar diameter, friction coefficient (COF), and seizure load, nanorods performed much better than the nanosheets. The hybrid exhibited highly advanced activity because of the synergy between noncovalently interacting nanorods and nanosheets. The SEM and AFM analyses of the wear pathway corroborated the tribological results. The energy-dispersive X-ray and X-ray photoelectron spectroscopy studies of the tribofilm confirmed the elemental composition and chemical states of all the elements, respectively. A possible mechanism of lubrication has been presented. © 2021 American Chemical Society.