Figure 4.

(a) Derivative (DTG) curve of the weight loss observed during the samples burn off process shifts to higher temperatures as the amounts of nitrogen introduced in the structures increase; (b) Corresponding mass spectroscopy data recorded during burn-off (mass 30). The measured ion current was normalized to the sample weight to account for differences in sample mass; (c) Variation in surface area values as the mass ratio of urea/GO increase. The same mass of sample for diverse formulations show a significant difference in mass volume.