Au/ZnO/In₂O₃ nanoparticles for enhanced isopropanol gas sensing performance

In this paper, a series of Au/ZnO/In2O3 nanoparticles are synthesized by a facile one-step hydrothermal method. The gas sensing properties of Au/ZnO/In2O3 materials are investigated in detail. The response of 2%Au/1%ZnO/In2O3 material to isopropanol increases to six times that of pure In2O3 materials. In contrast to a pure In2O3 sensor, the optimal working temperature of the 2%Au/1%ZnO/In2O3 sensor decreases to 40 C-degrees. The sensing mechanism of Au/ZnO/In2O3 nanoparticles is mainly explained through the influence of the n-n heterojunction formed by In2O3 and ZnO. In addition, the introduction of Au contributes to an increase in the gas response. A possible reason is that the introduction of Au produces smaller sized particles on the sensor surface, creating a larger surface area, enhancing the response.