Ethanol gas sensor based on a self-supporting hierarchical SnO2 nanorods array

3D array nanostructures assembled from 0D nanoparticles, 1D nanorods, nanowires, nanotubes, and 2D nanosheets on specific substrates are an important class of architecture in nanomaterials application. SnO2 nanostructure arrays on different types of heterogeneous substrates have been reported. Here, we provide a self-supporting 3D hierarchical SnO2 nanorods array on homogeneous substrate by a one-step solvothermal route with the help of an anionic surfactant. By investigating the morphology of products using different reaction conditions, the formation mechanism of the structure is proposed. The self-supporting SnO2 nanorods array is applied as a gas sensor to a series of harmful gases. It exhibited a high response (S-r = 22.69) to ethanol gas at a low concentration of 50 ppm at 260 degrees C. Its unique structure with a large surface area and interval space accounts for its good performance in gas sensing.