Temperature Dependence of the Sensor Characteristics of Oriented Ni/NiO Networks toward Nitrogen Dioxide

Nitrogen dioxide is one of the most hazardous pollutants in urban air, which underscores the need for reliable monitoring sensors. This work presents a sensing element for NO2 detection composed of an anisotropic metallic nickel network coated with a thin nickel oxide layer. The temperature dependence of the sensor response was examined over the range 25–180°C, and the response was found to increase progressively with temperature. The influence of humidity on the response becomes negligible at temperatures above 60°C, whereas operating temperatures exceeding 160°C lead to a deterioration in sensor stability. These results define an optimal temperature window that balances high sensitivity, reduced humidity interference, and long-term operational stability. At 140°C, the sensitivity to NO2 reached 8.3 × 10–3 ppm–1. The straightforward fabrication process and the low cost of the materials used make the sensor a promising candidate for modern air-quality monitoring systems.