Preparation and Gas-Sensitive Properties of Square–Star-Shaped Leaf-Like BiVO4 Nanomaterials

In this study, square-star-shaped leaf-like BiVO4 nanomaterials were successfully synthesized using a conventional hydrothermal method. The microstructure, elemental composition, and gas-sensing performance of the materials were thoroughly investigated. Morphological analysis revealed that BiVO4 prepared at different reaction temperatures exhibited square-star-shaped leaf-like structures, with the most regular and dense structures formed at 150 °C, exhibiting a large specific surface area of 2.84 m2/g. The response performance of the BiVO4 gas sensors to different target gases was evaluated, and the results showed that the prepared BiVO4 gas sensor exhibited a strong response to NH3. At the optimal operating temperature of 300 °C, its sensitivity to 5 ppm NH3 reached 13.3, with a response time of 28 s and a recovery time of 16 s. Moreover, the gas sensor exhibited excellent repeatability and anti-interference performance. These findings indicate that square-star-shaped leaf-like BiVO4 holds great potential in environmental monitoring and industrial safety detection, offering new insights for the development of high-performance gas sensors.