“…After entering the 21st century, aerogel category was booming. Lots of novel non-silica oxide aerogels [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], chalcogenide aerogels [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ], gradient aerogels (from 90 s) and other aerogel composites sprang up one after another [ 36 , 37 , 38 , 39 ]. Recently, novel aerogels such as carbon nanotube (CNT) aerogel [ 40 , 41 , 42 , 43 ], graphene aerogel [ 44 , 45 , 46 , 47 , 48 , 49 , 50 ], silicon aerogel and carbide (or carbonitride) aerogel were added into the aerogel community continually [ 51 , 52 , 53 , 54 , 55 ].…”