Synthesis and enhanced gas-sensing properties of mesoporous hierarchical α-Fe2O3 architectures from an eggshell membrane

Mesoporous hierarchical α-Fe₂O₃ was prepared by a simple soakage process and followed by calcination, using eggshell membrane (ESM) as a biotemplate. The hierarchical architectures composed of interconnected hollow nanotubes replicated from ESM and showed a large surface area (45.57 m² g^-1). A possible formation mechanism of the hierarchical α-Fe₂O₃ was proposed. Benefiting from the mesoporous hierarchical structures and high surface area, the ESM-morphic α-Fe₂O₃ sensor exhibits enhanced gas-sensing performance. The results demonstrated that the sensor showed the highest selectivity and sensitivity to acetic acid among the tested gases, and rapid response and recovery times (18 and 4 s to 50 ppm of acetic acid).