Multi-modal resonance of topological hybrid graphene foam for enhanced acoustic absorption

Utilizing the resonance of atomically thin graphene sheets has been proved as an efficient strategy to enhance the acoustic absorption. However, it still remains a great challenge to modulate the two-dimensional resonance modal for enhanced acoustic absorption. Here, we present a topologically hybrid graphene foam that integrates ultra-thin graphene drums with inorganic nanoparticles, achieving multi-modal resonance across 200 Hz to 2000 Hz by mass loading. The hybrid graphene foam shows a noise reduction coefficient of 0.34 and average sound absorption of 0.20, outperforming commercial counterparts. Moreover, the hybrid acoustic foam exhibits superior mechanical recoverability (∼100 cycles), high humidity resistance (∼98 % relative humidity) and excellent inflaming retarding (∼40 % limit oxygen index). In practical noise absorption applications, the foam's noise attenuation efficiency is 500-fold greater than commercial melamine foam. This work not only demonstrates a facile strategy to modulate the resonance modal of graphene nanowalls, but also provides opportunities to the large-scale application of graphene in acoustic engineering applications.