Hydrogen sulfide (H₂S), even in trace amounts, poses serious risks in industrial and environmental settings. However, current detection methods struggle with sensitivity and selectivity. To address these challenges, in this work, metal-organic framework (MOF)-derived N-doped graphitic carbon sensors have been explored for trace H₂S detection. Through temperature-controlled post-processing, the sensors exhibit a detection limit of 56.9 ppb, faster response and recovery time (18s and 29s), and high selectivity with 20 folds response difference than other interfering gases. The expected stability with stable multiple consecutive responses, and a strong response towards 1 ppm H2S after 4 months was reached. Key to this performance is the pyridinic and pyrrolic nitrogen groups within the N-doped carbon, which create reactive sites for H₂S interaction. These interactions drive dual mechanisms for gas detection, with further optimization of pyrolysis revealing a switching behavior between Schottky and ohmic contacts, which enhances sensor sensitivity at low temperatures. Our work demonstrates that MOF-based sensors provide a promising solution for highly sensitive, selective, and durable H₂S detection, contributing to more effective monitoring systems in both industrial and environmental contexts.