Significance of g-C3N4 nanosheets for enhancing tribological performance of epoxy subjected to starved lubrication

It is of great interest to realize controllable tribo-designs of a large variety of motion components operating under starved lubrication conditions. In this work, g-C3N4 nanosheets were prepared and uniformly dispersed into pure epoxy (EP) matrix. Especially for sliding with only 5 μL oil supply. In comparison to neat EP, friction coefficient and wear rate are reduced by up to 27% and 83% with addition of only 1% g-C3N4. Research illustrates a small amount of two-dimensional g-C3N4 nanosheets promote the growth of robust tribofilm on oil starved interface. The carbonous top layer of tribofilm benefits the boundary lubrication effect of the sliding pair, whereas the beneath layer confers a high load-bearing ability to tribofilm. It is anticipated that this work will pave a route for designing new polymer nanocomposites serving under oil starved conditions. •g-C3N4 nanosheets were synthesized and uniformly dispersed into EP matrix.•g-C3N4 reinforced EP nanocomposites exhibit better tribological performance with lowering lubricant oil supply.•Adding 1% g-C3N4 nanosheets into EP lowered friction and wear by 27% and 83% under 5 μL oil supply lubrication.•A protective tribofilm grew on steel surface slid against EP reinforced with g-C3N4 nanosheets.