Preparation of Three-Dimensional NiO Gas Sensor for Monitoring the Indoor Air of Car Cabs

A novel three-dimensional NiO was synthesized by a simple hydrothermal reaction. Characterization and gas-sensing performance of NiO with flower like spheres were tested. Owing to its three-dimensional structure, the NiO obtained large specific surface area and abundant active sites. Furthermore, the gas sensors showed the enhanced formaldehyde sensing performance obtained a gas response of 26.3 to 200 ppm formaldehyde at 350 °C, short response/recovery time as 6 and 11 s, and excellent stability. These results indicate that the three-dimensional NiO flower-like spheres play an important role on the VOCs sensing performance for practical detectors.