Significantly energy-efficient ethanol sensor based on bougainvillea-like Au/ZnO hierarchical nanostructured materials

Abstract

The energy consumption of MOS (metal oxide semiconductor) sensors has always been a challenge in improving their performance. In this study, bougainvillea-like Au/ZnO nanostructures were successfully synthesized using the hydrothermal method and the sol fixation technique. The composition, crystallinity, crystal structure, and morphology of the materials were characterized using X-ray diffraction, energy-dispersive spectroscopy, and field emission scanning electron microscopy. The experimental results confirm the successful synthesis of a substantial quantity of bougainvillea-like Au/ZnO nanostructures through nanoparticle self-assembly. The sensitive performance of the bougainvillea-like Au/ZnO sensor was evaluated using a CGS-8 intelligent gas-sensitive analysis system. Results demonstrate that modification of ZnO with Au in a bougainvillea-like nanostructure significantly enhances sensitivity to ethanol vapor compared to those of unmodified material sensors. Specifically, the optimal work temperature was greatly reduced by 64%, whereas the sensitivity increased approximately 12 times and the response time decreased nearly 5 times. The significantly enhanced ethanol sensitivity can be attributed to the precious metal modification and unique three-dimensional morphology. It provides the necessary experimental exploration for reducing energy consumption and improving the performance of MOS gas sensors.