Graphitic carbon nitrogen supporting h-BN nanosheets as lubricating additive: Enhancing mechanism on epoxy composite coating

Creating high-quality and highly adaptable self-lubricating surfaces at the interface of mechanical components is significant in extending the lifespan of equipment. Due to the limitations of the performance of a single nanofiller, its enhanced polymer-based coatings often struggle to meet the requirements of harsh working environments. In this study, the 2D/2D nanohybrid of graphitic carbon-nitrogen (g-C 3 N 4 ) supporting h-BN nanosheets (BNNSs) was prepared using the facile calcination method. Furthermore, its tribological enhancement on epoxy (EP) composite coating was evaluated by sliding against 440 C steel ball. The “soft phase” of g-C 3 N 4 and “hard phase” of BNNSs in 2D/2D BNNSs/g-C 3 N 4 nanohybrid could integrate the multiple advantages and provide synergistic enhancement for epoxy self-lubricating composite coating. The BNNSs/g-C 3 N 4 demonstrated the optimal lubricating properties for EP compared to single BNNSs or g-C 3 N 4 . Compared with the pure EP coating, the friction coefficient and wear rate of the 0.5 wt% BNNSs/g-C 3 N 4 /EP coating were reduced by approximately 74.5 % and 80.9 %, respectively. The outstanding tribological properties of BNNSs/g-C 3 N 4 /EP were mainly due to the synergistic enhancement of BNNSs and g-C 3 N 4 nanosheets and the lubricating effect of high-quality transfer film.