Enhanced gas sensing performance to ethanol of ZnO based on Ag modification by a simple solid-state reaction method

In this paper, silver (Ag) nanoparticles modified zinc oxide (ZnO) nanoparticles (Ag–ZnO) were prepared by a simple solid-state reaction. Zn(NO 3 ) 2 ·6H 2 O and AgNO 3 were grinded and mixed in proportion and calcined at 500 °C for 2 h. The molar ratios of Ag to Zn in the precursors were 0, 1.0, 3.0, 5.0, 7.0 and 10.0%, respectively. The microstructure of Ag–ZnO before and after modification was observed by scanning electron microscope. The existence of Ag was proved by X-ray diffraction, energy dispersive spectrum and Raman spectra. The lattice of ZnO after modification of Ag particles was changed. Ag-modified ZnO nanoparticles showed good gas sensitivity to ethanol due to the increasing oxygen vacancy amounts. The 5.0% modified Ag–ZnO based gas sensor obtained the fastest response recovery and the highest sensitivity to ethanol. The Ag–ZnO-based gas sensor will be a promising candidate in the application of ethanol detect. Graphical abstract