The co-enhanced effect of Zn-doping and Ag-loading on the selectivity of a p-type Fe2O3 toward acetone

The sensitivity and selectivity of semiconductor metal oxides can be effectively improved by transition metal doping and noble metal loading. In this work, Ag-loaded p-type Zn-doped Fe2O3 (Ag@Zn–Fe2O3) nanoparticles were synthesized by a combination of a one-step hydrothermal route and a co-precipitation method. The prepared Ag@Zn–Fe2O3 nanoparticles show a peanut-like structure with a size of about 50–150 nm. The Zn doping and the Ag loading can synergistically improve the response of the Fe2O3 nanoparticles to acetone. At the optimum operating temperature (150 °C), the response of the Ag@Zn–Fe2O3 sensor to 100 ppm acetone is 50.2, which is significantly higher than 8.9 and 25.8 corresponding to Fe2O3 and Zn–Fe2O3, respectively. In addition, the Ag@Zn–Fe2O3 sensor exhibits excellent selectivity, good moisture resistance, and long-term stability to acetone. Meanwhile, the possible mechanism of the improved acetone sensing properties is also discussed.