MOF–Derived 1 D α–Fe2O3/NiFe2O4 heterojunction as efficient sensing materials of acetone vapors

Abstract

Abstract The key challenge to develop gas sensors with high performances lies in the novel design of superior functional materials for effective reactions between target gases and sensing layers. Metal–organic frameworks (MOFs) have emerged as versatile candidates for preparation of ideal nanostructured materials with controllable composition, various structures and tunable pore size. Herein, a series of Fe–based and Fe/Ni–based one–dimensional (1D) nanostructures using MOFs as templates were prepared systematically. As a result of the hollow structure and nanohybrid features, the optimized α–Fe2O3/NiFe2O4 nanotubes can exhibit high specific surface area (118.03\u2009m2\u2009g−1) and provide a mass of active sites compared to individual components (α–Fe2O3 nanowires and NiFe2O4 nanowires), which is beneficial to improve the response (Ra/Rg\u2009=\u200923) to acetone vapors. In addition, the smart design also endows the sensor based on α–Fe2O3/NiFe2O4 nanotubes with good selectivity, fast response time (4\u2009s) and long–term stability (30 days). In this work, the advantages of 1D hollow heterogeneous materials will provide a new perspective of MOF–derived nanostructures for the particular application in acetone gas sensors.