Fig. 2
SEM images of the synthesized ultramarine pigment and the corresponding elemental mapping of Al, Si, O, S, Na (The different Na2CO3/S mass ratios of 0.25, 0.5, 1, 1.5, 2, 2.5 used for ultramarine pigments synthesis were denoted as U1-U6).
Fig. 2 | Scientific Reports
