Controllable synthesis of porous 3D Pd loaded ZIF-67/g-C3N4 hierarchical nanostructure for efficient detection of NO2 gas at room temperature

The two-dimensional (2D) g-C3N4 nanosheets have been widely recognized for their great potential in gas sensing. However, the disadvantages brought by layer stacking of two-dimensional nanosheets also seriously affect their performance and application. In this paper, three-dimensional hydrangea-like Pd-ZIF-67/g-C3N4 was prepared for the detection of nitrogen dioxide gas at room temperature via a simple hydrothermal method. The Pd-ZIF-67/g-C3N4 gas sensor exhibited excellent sensing properties with highest sensing response (23.8–100 ppm), ultrafast response speed (0.5 s) and lowest limit of detection (10 ppb) at room temperature. Moreover, it also manifests excellent reversibility and durability, optimal stability and commendable selectivity towards NO2 gas. This excellent performance is due to the three-dimensional spatial configuration, synergistic effect and catalytic action of Pd. In general, the constructed structure and the proposed design strategy have a certain promoting role in promoting the creation of high performance gas sensors with three-dimensional heterogeneous structures based on two-dimensional nanosheets.