Figure 3

SEM images of extracted EHL (a) and carbon spheres at EHL concentrations of 0.04 g ml−1 (b), 0.06 g ml−1 (c) and 0.08 g ml−1 (d) (the carbonization temperature and time were 270 °C and 7 h, respectively).
SEM images of extracted EHL (a) and carbon spheres at EHL concentrations of 0.04 g ml−1 (b), 0.06 g ml−1 (c) and 0.08 g ml−1 (d) (the carbonization temperature and time were 270 °C and 7 h, respectively).