Highly electron-depleted ZnO/ZnFe2O4/Au hollow meshes as an advanced material for gas sensing application

Abstract

The size of sensing materials matters a lot to the performance of gas sensors. Herein, size-controlled three-component ZnO/ZnFe2O4/Au nanomeshes were elaborately prepared by combining electrospinning, atomic layer deposition and room-temperature solution reaction methods. The as-prepared ZnO/ZnFe2O4/Au is characterized by uniform ZnO nanotube skeletons (˜50 nm), ultrathin ZnFe2O4 nanosheets (˜10 nm) and well-dispersed Au nanoparticles. To demonstrate the superiority of such ultrafine ZnO/ZnFe2O4/Au nanomeshes, a comparison of sensing performance between the gas sensors fabricated by pristine ZnO, ZnO/ZnFe2O4 and ZnO/ZnFe2O4/Au was carried out. Results of the measurement evidence that the sensor based on ZnO/ZnFe2O4/Au nanomeshes exhibited the highest sensing response, significantly enhanced selectivity, and faster response/recover speed compared with the other two reference counterparts. The response of ZnO/ZnFe2O4/Au towards acetone was improved about 3-fold versus the ZnO/ZnFe2O4 composites and 5.5-fold versus pristine ZnO. The enhanced gas sensing performance was found to be closely related to the highly electron-depleted layer derived from the small material size and the interfacial heterojunctions as well as the sensitization effect endowed by the Au nanoparticles. This study shows the great potential of ZnO/ZnFe2O4/Au nanomeshes on acetone detection and provides a promising mean for the rational design of high-performance gas sensor.