Conversion of Fe2O3 from n to p type via transition metal (Cu, Zn) doping for the preparation of high-performance acetone sensors

Abstract

In this work, Fe₂O₃ nanocubes doped with different amounts of transition metals (Cu and Zn) were prepared by a hydrothermal synthesis and annealing method. Gas sensing performance tests show that the prepared pristine Fe₂O₃ exhibits the conductive properties of an n-type material, while Cu&Zn doped Fe₂O₃ exhibits p-type conductive properties. The sensors based on 5 at% Cu&Zn doped Fe₂O₃ showed significantly improved response, selectivity, long-term stability, and moisture resistance to acetone compared to the pristine Fe₂O₃ nanocubes. X-ray photoelectron spectroscopy (XPS) results confirmed that the adsorbed oxygen on 5 at% Cu&Zn doped Fe₂O₃ was significantly higher than that on pristine Fe₂O₃, which is the main reason for the improved gas sensing performance. Therefore, this study provides an effective way to develop low-cost and high-performance gas sensors based on transition metal-doped metal oxides.