Enhanced Acetone-Sensing Performance of Au/Y-ZnO Composite Prepared Using a Facile Wet Chemical Method

Au/Y-ZnO composite with excellent acetone sensing was successfully prepared by a facile wet chemical method. X-ray diffraction analysis, field-emission scanning microscopy, and transmission electron microscopy investigation revealed that the obtained Au/Y-ZnO was mainly composed of ZnO wurtzite phase and Au nanoparticles with a face-centered structure in diameter of 10 nm, and Y atom replaced Zn lattice sites to form yttria phase. Compared with the pure ZnO and Y-doped ZnO, the Au/Y-ZnO-based sensor shows significantly enhanced acetone gas sensing. Its response to 100 ppm acetone is 27.6, which is about 2.3 and 5.5 times that of the Y-ZnO and the pure ZnO, respectively. The Au/Y-ZnO-based sensor has a low detection limit (1 ppm), and fast response (3 s) and recovery (9 s). Au modification can obviously decrease the operating temperature (275°C). The enhanced gas-sensing of Au/Y-ZnO towards acetone can be ascribed to Y Zn and V − Zn defects, the Schottky barrier between Au nanoparticles and Y-doped ZnO, and the catalytic activity of the Au nanoparticles.