In situ construction of hierarchical MgAl-LDH/rGO coatings on wood fibers for synergistic flame retardancy and smoke suppression

Wood fibers are promising for green building applications due to their renewability and availability, yet their intrinsic flammability poses a critical safety limitation. Here we report a hierarchical coating strategy that integrates reduced graphene oxide (rGO) with MgAl-layered double hydroxide (LDH) to create flame-retardant wood fibers. The fabrication involves in situ hydrothermal growth of LDH on wood fibers using pre-coated graphene oxide (GO) as a template, during which GO is simultaneously reduced to rGO. The resulting LDH@rGO@WF exhibits markedly improved fire safety performance compared to unmodified fibers, including reductions of 20.0% in peak heat release rate, 28.7% in total heat release, 41.5% in total smoke production, and 26.6% in peak CO yields, together with a 75.6% increase in residue mass. These enhancements arise from a synergy between MgAl-LDH and rGO: rGO promotes uniform LDH anchoring and constructs a tortuous physical barrier to heat and mass transfer, while LDH provides endothermic cooling, catalyzes protective charring, and suppresses flammable volatiles. Additionally, the composite achieves an electrical conductivity of (2.12 ± 0.92) × 10 −3 S m −1 , meeting antistatic requirements. This work provides a scalable approach for engineering multifunctional wood fibers, enabling their future integration into advanced biocomposites with enhanced safety and functionality.