Tailoring the Porosity of 3D Tin Oxide Nanostructures Using Urea for Sensing and Photovoltaic Applications

High yield of three-dimensional (3D) tin oxide (SnO₂) sea-urchin nanostructures have been successfully achieved via an economical hydrothermal process without the use of any physical template. The morphology of the synthesized nanostructures can be considered as one-dimensional (1D) nanorods assembled on a 3D core with a relatively high surface area (∼132 m²/g). The specific surface area and morphological structure of the SnO₂ nanostructures can be effectively tuned via the concentration of urea. The sea-urchin SnO₂ nanostructures show good sensing properties towards hydrogen gas at room temperature, where the detection limit can be as low as 50 ppm. Furthermore, the SnO₂ nanostructures can be effectively used as photoanode for dye-sensitized solar cell (DSSC). The unique hierarchical 3D structure formed by radially assembled nanorods provides an ideal platform for sensor and photovoltaic applications which specifically require high surface area and highly interconnected nanostructures for optimal device performance.