Synthesis of ZnO–Ag Hybrids and Their Gas-Sensing Performance toward Ethanol

Herein, we describe a facile surfactant-free method to prepare the ZnO–Ag hybrids at room temperature for improving gas-sensing performance toward ethanol. Characterizations indicate that Ag nanoparticles are well deposited on the surface of ZnO nanorods. It is interesting to note that the introduction of only 1 wt % Ag in ZnO–Ag hybrids leads to the impressive enhancement in gas-sensing properties of ZnO. Notably, the ZnO–Ag hybrids can offer a gas response value of 884.7 toward 1000 ppm of ethanol (approximately 12.6 times higher than pure ZnO nanorods). Meanwhile, the hybrids exhibit excellent stability with only ±5% fluctuation of the gas response value over a period of 480 cycles. Moreover, the above-mentioned hybrids also exhibit good selectivity (about 4.7–52.9 times greater than that of other tested vapors). The high sensitivity, good selectivity and excellent stability presented by ZnO–Ag hybrids make it a potential material for developing an excellent gas-sensing sensor toward ethanol.