Directly freeze-drying porous graphene aerogel as acoustic-absorbing material

Noise pollution, which is no less harmful than air, water and soil pollution, is becoming an environmental shortcoming that cannot be ignored. Scientists are also seeking various solutions to work on reducing noise pollution. In this work, porous graphene aerogel (FD-GA) and porous graphene oxide aerogel (FD-GOA) prepared by foaming combined with freeze-drying are reported as acoustic-absorbing materials. The effects of thickness and degree of compression on the acoustic-absorbing performance of FD-GA and FD-GOA in the 1000- 6000 Hz range, where human ear hearing is sensitive, were investigated, respectively. FD-GA was found to have significantly higher acoustic absorption performance with a peak absorption of 96.7%. The present work provides a simple and straightforward strategy for the synthesis of the acoustic-absorbing material. Key words: freeze-drying, graphene aerogel, acousticabsorbing.