Ultrastrong SiC/LDHs biomass aerogel with exceptional fire safety behavior

• The SiC/LDHs/MOH nanocomposites was first designed. • The mechanical and flame-retardant performance of aerogel composites is greatly enhanced. • The mechanism of the enhancing fire safety behavior is proposed. Assembled Silicon Carbide/Layered Metal Hydroxides (SiC m /LDHs) in macroscopic biomass aerogels have challenges such as weak interfacial interactions, which degrade the mechanical properties. We successfully synthesized silicon carbide/cobalt-aluminum layered double hydroxide/magnesium hydroxide (MOH) ternary composites with high aspect ratios to improve the flame retardant and smoke suppression properties of polyvinyl alcohol (PVA)/sodium alginate (SA) biomass aerogel (PS). The inclusion of SiC m /LDH/MOH (2 wt%) greatly intensified the charring effect of PS, leading to a notable suppression of flame combustion and a reduction in smoke production. Specifically, the peak heat release rate (pHRR) and total smoke release (TSR) were decreased by 18.4% and 30.5%, respectively, in comparison to pure PS. The compressive characteristics of PS aerogels were notably enhanced through the incorporation of SiC m /LDH/MOH, particularly PS-S/L/M−4%, which exhibited a 220.4% increase compared to pure PS. The favorable formation of multiple hydrogen bonds and interconnected interfacial structures in ternary composites thus synergistically contributes to the achievement of superior mechanical and flame retardant properties. Our work offers a brighter future for the green manufacturing of biomass aerogels reinforced with SiC m /LDHs.