Fig. 1. Graphite is effectively removed by heating at 445 ± 5 °C for 5 hours. (a) Thermogravimetric analysis shows that mass is slowly lost at a rate of –1.20(2)% per hour. NSample = 1. (b) Raman spectra show that the graphitic signal (1575 cm–1) is reduced relative to the diamond signal (1332 cm–1) under heating conditions. At 445 ± 5 °C, the area under the curve is reduced by 76 ± 9% indicating the sample has been oxidized (p = 2.2 × 10–12). NDataPoints = 16 000.
