Fig. 4. SEM images of the particles prepared using the initial precursor concentration of 0.05 (a and d); 0.3 (b and e); and 1.00 mol L−1 (c and f) before (a–c) and after (d–f) the annealing process. (g and h) are the TEM images of particles prepared using an initial precursor of 0.05 and 1.00 mol L−1, respectively.
