Table 1. General Properties and Applications of Some Aerogels and Xerogels^a.

gel type	composition	SSA (m2 g–1)	Vp (cm3 g–1)	ρ (g cm–3)	application(s)	reference(s)
aerogels	SiO2	366–1100	2.7–18	0.003–0.35	catalysis, cosmic dust capture, thermal insulation	(15, 27, 31, 34, 40)
	Al2O3	123–616	1.1–17.3	0.06–0.13	catalysis, thermal insulation	(27, 31, 39)
	Cr2O3	528–784	1.3–3.7	0.15–0.54	catalysis	(27, 33)
	Fe2O3–SiO2	690–760	NP	NP	catalysis	(41)
	Fe2O3l2O3	230–570	2.7–13	∼0.05	catalysis	(27, 42)
	Al2O3–SiO2	600–780	NP	0.1–0.2	thermal insulation	(38)
	Al2O3–SiO2	96–150	0.3–0.7	NP	iodine capture	(1, 5, 7)
	partially sintered composite silica	11–44	NP	0.39–1.49	actinide immobilization	(36)
graphene aerogels	carbon	149–1100	2–4	∼0.05	catalysis, energy storage, electrode, sensor, sorbent	(8, 17, 18, 20, 22, 24)
	carbon + TiO2	268, 323	0.1	NP	catalysis	(20, 23)
	carbon + Fe3O4–N	110	NP	NP	catalysis	(19)
	carbon + W18O49	228	0.5	0.01	catalysis	(21)
chalcogenide aerogels (chalcogels)	Co(Ni)–Mo(W)–S	340–528	0.7–1.2	0.19–0.3	catalysis	(43)
	Fe4S4	90–310	NP	NP	catalysis	(25)
	Fe–Mo–S	144	NP	NP	catalysis	(44)
	Co(Ni, Sb, Zn)–Mo(K, Sn)–S	240–490	NP	NP	sorbent	(26)
	Co-Bi(Ge, Ni)–Mo–S	127–580	0.7–3.0	NP	Tc, U, and I capture	(6)
xerogels	SiO2	141–491	∼0.1	NP	optical material, medication carrier	(45−47)
	Pt-carbon	625–660	0.8–1.1	NP	catalysis	(48)
	Ag(Cu, Pd)–SiO2	200–570	1.3–7.3	∼2.2	catalysis	(49)
	SnO2	NP	NP	NP	sensor	(50)
	ZrO2–SiO2	38–115	0.2–0.4	NP	sensor	(51)
	analine–SiO2	192	0.3	NP	sensor	(52)
	Ag–Al2O3–SiO2	240	0.7	NP	iodine capture	(47)

^aNP denotes “not provided”. Reported densities (ρ) are apparent densities. SSA and V_p denote the specific surface area and pore volume, respectively.