Table 1.

Molar ratio of Fe/Si at different heights of the composition-gradient aerogel.

Measure Plane	Height from the Bottom (mm)	Molar Ratio of Fe/Si (%)
Position A	2	18.48 ± 0.26
Position B	11	11.56 ± 0.29
Position C	20	5.06 ± 0.76
Position D	29	3.61 ± 0.09
Position E	38	2.14 ± 0.32