Enhanced Isopropanol Sensing Performance of the CdS Nanoparticle Decorated ZnO Porous Nanosheets-Based Gas Sensors

In present work, the CdS nanoparticle decorated ZnO porous nanosheets (CdS NP/ZnO PNs) were successfully synthesized through a facile wet-chemistry method. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectrum. The results proved the porous and monocrystalline structures of the ZnO nanosheets. A huge number of tiny CdS nanoparticles evenly cover the surface of the ZnO porous nanosheets, and the average size of the CdS nanoparticles is about 5 nm. The CdS NP/ZnO PNs exhibit excellent sensing activity and selectivity towards isopropanol. The linear response range is 1-100 ppm under the optimized operation temperature of 320 °C, and the detection limit is 1 ppm. The sensing performance of the CdS NP/ZnO PNs towards isopropanol is dramatically higher than that of other VOC gases, indicating the high selectivity to isopropanol. The CdS NP/ZnO PNs based sensor even can distinguish isopropanol from the complex mixed gases. Besides, the responses of the as-prepared sample to isopropanol seldom changed within 15 days. It is believed that the CdS NP/ZnO PNs have great application potential in isopropanol detection.