Graphene-Enhanced Cobalt-Doped ZnO Nanoparticles for Highly Sensitive Acetylacetone Detection at Low Concentrations

Acetylacetone is a highly volatile, flammable, and toxic compound that emits an irritating odor and poses significant threats to human survival and safety. Consequently, rigorous monitoring of acetylacetone concentrations is essential. Herein, we successfully synthesized GO-modified Co-doped ZnO (8-ZOC, 8 wt % Co/Zn) nanoparticles (NPs) with different GO contents (0.01-0.03 g) using a secondary hydrothermal method for the first time, achieving excellent performance in detecting low concentrations of acetylacetone gas. Among all samples, the sensor with a GO content of 0.02 g exhibits the highest response (598.22) to 5 ppm of acetylacetone at 250 °C, with a value 9.28 times higher than the response of 8-ZOC (64.50). Meanwhile, GO/8-ZOC-2 exhibits a rapid response, requiring only 3 s, which is 50% faster than 8-ZOC, and also features a recovery time that is 74 s shorter. Additionally, it presents outstanding selectivity and reproducibility and excellent long-term stability. The enhanced gas sensing performance of GO/8-ZOC-2 results from the combined effect of multiple factors, including the abundant oxygen vacancies created by GO modification, the relatively high specific surface area, and the synergistic effect of the p-n heterostructure. The excellent sensing performance exhibited by GO/8-ZOC materials endows them with significant potential for practical applications in the field of acetylacetone gas sensors.