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

In this work, Fe2O3 nanocubes doped with different amounts of transition metals (Cu, Zn) were prepared by hydrothermal synthesis and annealing method. Gas sensing performance tests show that the prepared pristine Fe2O3 exhibits the conductive property of an n-type material, while Cu&Zn doped Fe2O3 exhibit p-type conductive property. 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 of 5 at% Cu&Zn doped Fe2O3 were significantly higher than that of the pristine Fe2O3, which is the main reason for the improved gas sensing performances. Therefore, this study provides an effective way to develop low-cost and high-performance gas sensors based on transition metal-doped metal oxide.