Preparation of flower-like hierarchical structure SnO2/g-C3N4 and its ethanol gas-sensitive properties

The flower-like hierarchical structured SnO2/g-C3N4 nanocomposites were successfully prepared by one-step hydrothermal method with high-temperature calcination. The structure and morphology of the synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption-desorption. The gas-sensitive performance of the pure SnO2 and SnO2/g-C3N4 sensors were investigated and compared towards ethanol gas. The results showed that the response of the SnO2/g-C3N4 composites to 100 ppm ethanol gas at 200 °C was 18.88, which was 2.09 times that of pure SnO2, with response and recovery time of 2 s and 13 s. In addition, the gas sensor has excellent selectivity for ethanol gas, good repeatability, and long-term stability. These gas-sensitive properties of the flower-like graded structure SnO2/g-C3N4 to ethanol gas are attributed to the materials which have unique graded structure and n-n heterojunction. KEY WORDS: Hierarchical structure, SnO2/g-C3N4, Gas sensing property Bull. Chem. Soc. Ethiop. 2025, 39(1), 141-152. DOI: https://dx.doi.org/10.4314/bcse.v39i1.12