In a direct comparison of the 5N load tests, ML (Ni) shows peaks consistent with a graphitic material; two distinct bands at approximately 1605 and 1350 cm -1 , attributed to the G-and Dbands of GnP. There is an additional broad peak at ~800 cm -1 which is consistent with organic-based vibrations from the dispersing agent bound to the GnP nanosheets. The intensity and shape of the peaks do not significantly alter on longer sliding tracksfeatures consistent with the formation of a robust tribofilm. In contrast, the graphitic peaks in ML (Cu)