Abstract
Abstract
Hydrogen sulfide (H2S) poses significant risks in industrial settings due to its high toxicity and flammability, making its efficient detection crucial for operational safety. In this study, high-performance MEMS gas sensors based on a nitrogen-doped carbon quantum dot/nickel cobaltite (N-CQD/NiCo2O4) nanocomposite were developed, achieving highly sensitive H2S detection. Characterization techniques such as XRD, XPS, SEM, and TEM confirmed the successful loading of N-CQDs onto the NiCo2O4 surface, leading to an increase in oxygen vacancy concentration. The sensor with NCQD/NCO-2 exhibited excellent H2S selectivity, good repeatability, and long-term stability over 40 days. At low-temperature heating, the response to 1000 ppm H2S was enhanced by a factor of 6.84, with a theoretical detection limit of 9.42 ppb. Beyond the material-level enhancement, this work integrates N-CQD-mediated surface/interfacial activation, a low-temperature-heated MEMS sensor array, and a lightweight temporal regression model for H2S quantification. The DCG-Net model achieved accurate concentration prediction with an R2 value of 0.9902 and was successfully deployed, offering a compact material–device–algorithm solution for intelligent H2S monitoring.