Preparation and Research of a High-Performance ZnO/SnO2 Humidity Sensor

A high-performance zinc oxide/tin dioxide (ZnO/SnO2) humidity sensor was developed using a simple solvothermal method. The sensing mechanism of the ZnO/SnO2 humidity sensor was evaluated by analyzing its complex impedance spectra. The experimental results prove that the ZnO/SnO2 composite material has a larger specific surface area than pure SnO2, which allows the composite material surface to adsorb more water to enhance the response of the ZnO/SnO2 humidity sensor. ZnO can also contribute to the generation of oxygen-rich vacancies on the ZnO/SnO2 composite material surface, allowing it to adsorb a large amount of water and rapidly decompose water molecules into conductive ions to increase the response and recovery speed of the ZnO/SnO2 humidity sensor. These characteristics allowed the Z/S-2 humidity sensor to achieve a higher response (1,225,361%), better linearity, smaller hysteresis (6.6%), faster response and recovery speeds (35 and 8 s, respectively), and long-term stability at 11-95% relative humidity. The successful preparation of the ZnO/SnO2 composite material also provides a new direction for the design of SnO2-based resistance sensors with high humidity-sensing performance.

Automated summary

A high-performance ZnO/SnO2 humidity sensor was developed using a solvothermal method, and its sensing mechanism was evaluated by analyzing impedance spectra. The experimental results showed that the ZnO/SnO2 composite material had a larger specific surface area, allowing it to adsorb more water and improve the sensor's response. The presence of ZnO also contributed to the absorption and decomposition of water molecules, increasing the sensor's response and recovery speed.