Assembling a high-performance acetone sensor based on MOFs-derived porous bi-phase α-/γ-Fe2O3 nanoparticles combined with Ti3C2Tx nanosheets.

[Display omitted] • The porous bi-phase α-/γ-Fe 2 O 3 nanoparticles are derived from MIL-53(Fe) for the first time. • The assembling of porous bi-phase α-/γ-Fe 2 O 3 nanoparticles in exfoliated Ti 3 C 2 T x nanosheets generates high-performance α-/γ-FT-X acetone sensing material. • Improved sensitivity due to multiple heterojunction interfaces, surface defects, and porosities. • Novel sensing mechanism is proposed and investigated. Acetone is one of the volatile organic compounds (VOCs), which is found in precarious both human health and the environment. For efficient detection of acetone gas concentration and leakage, we have successfully synthesized stable α-/γ-Fe 2 O 3 /ex-Ti 3 C 2 T x -X gas sensing material via in-situ solvothermal and calcination method, in which MIL-53(Fe)-derived porous bi-phase α-/γ-Fe 2 O 3 nanoparticles uniformly growing on the surface and interlayers of exfoliated Ti 3 C 2 T x nanosheets (α-/γ-FT-X). The numerous heterojunction interfaces, surface defects, and porosities of α-/γ-FT-X composites can simultaneously facilitate the diffusion process and contact interaction between acetone molecules and active sites. Strikingly, the optimal α-/γ-FT-4 composite possesses the superior sensitivity (R = 215.2) towards 100 ppm acetone at 255 ℃, which is nearly 8 times higher than that of α-/γ-Fe 2 O 3 (R = 26.2) and much higher than exfoliated Ti 3 C 2 T x nanosheets (R = 3.8), respectively. Moreover, fast response (13 s) and recovery (8 s) properties are achieved, as well as outstanding repeatability and remarkable selectivity. An enhancement mechanism for α-/γ-FT-4 composite is proposed and investigated. It is expected for us to open an effective avenue for fabricating efficient acetone sensing materials. [ABSTRACT FROM AUTHOR]