Simple synthesis of hydrangea-like CuO structure constructed by porous nanosheets for rapid detection of NO2 at low temperature

[Display omitted] •CuO hydrangea-like material has the porous structure.•CuO hydrangea-like material has the large specific surface area (42.45 m2·g−1).•The CuO hydrangea-like flower sensor to 10 ppm NO2 has fast response (4 s) at 50 ℃.•The synthesis method of CuO hydrangea-like material can meet large-scale production.•CuO hydrangea-like flower sensor exhibits excellent gas sensing performance to NO2. It is of great significance to develop gas sensors with fast and high response under low energy consumption for practical monitoring of harmful gases in industrial production and environment. In this work, hydrangea-like CuO material constructed by porous nanosheets with a specific surface area of 42.45 m2 · g−1 was synthesized by a simple one-step solution method without the addition of surfactant. It has good sensing performance to 10 ppm NO2 (S = 133.6) and short response time (4 s) at near room temperature (50 ℃), which is significantly superior to most CuO based NO2 gas sensors reported so far. The good gas sensing properties may be attributed to the synergistic effect of large specific surface area and two-dimensional porous structure. Therefore, hydrangea-like CuO may become a popular sensitive material capable of rapid detection of NO2, and the synthesis method of this material can also meet large-scale production.