MOF-on-MOF nanoarchitecturing of Fe₂O₃@ZnFe₂O₄ radial-heterospindles towards multifaceted superiorities for acetone detection

Rational integration of multifunctions is an emerging strategy to develop novel chemiresistor nano platforms with superior sensing properties. Herein, a stepwise synthesis strategy is developed to assemble two MOFs with huge mismatch into MOF-on-MOF heterojunction, which was nanoarchitectured into Fe₂O₃@ZnFe₂O₄ radial-heterospindles. The Fe₂O₃@ZnFe₂O₄ heterospindles exhibited outstanding selective acetone detection with multifaceted superiorities, such as high response, low limit of detection, fast response and recovery time, and good linearity in responses with a wide concentration window. An in-depth discussion revealed that such multifaceted sensing characters can be attributed to the distinct radial-heterostructure which proffer synergetic effects in the unimpeded gas diffusion with mesoporous sensing nanoarchitecture, favored interfacial charge transport in radial heterojunction, abundant active adsorption/reaction sites by rich oxygen vacancies, and exponential/efficient tuning of sensor resistance with barrier height. This synthetic strategy here may offer a new opportunity for fabricating dual-to-multi MOFs-based advanced nanostructures towards practical chemiresistor nanoplatforms with favorable multifaceted superiorities.