ZnO:SiO2 films are prepared by sol-gel technique on Si substrates. The effect of annealing temperatures (T-a) on the structure, surface morphology, and optical and photoluminescence (PL) properties of these films is studied. The X-ray diffraction analysis revealed that the c-axis orientation and the grain size of ZnO: SiO2 films increased at high Ta. High-resolution transmission electron microscopy results showed that the ZnO nanoparticles are spherical in shape with their size increasing from 5 to 15nm with T-a while PL spectroscopy showed few separated PL bands. In addition, two optical band gaps located at 3.0 eV and 4.2 eV are observed and showed a redshift with Ta up to 600 C, and then a blueshift is observed at 800 C. ZnO: SiO2 film was tested as sensors for the detection and quantification of phenyl hydrazine. It is found that ZnO: SiO2 films showed good sensitivity of 390 mu A mM(-1) cm(-2) and a lower limit of detection of 3 mM with linear dynamic range of 0.05 mM to 3 mM and rapid reaction kinetics (in the order of seconds). The cycling tests indicated that the ZnO: SiO2 films are quite stable since no significant decrease in sensitivity was observed even after being used repetitively for 3 times, showing a good potential for practical applications. (C) 2014 Elsevier B. V. All rights reserved.