High-sensitivity and flexible H2S gas sensor based on PVA/PEO–CoO/MoO3 nanocomposite films

• A novel PVA/PEO–CoO/MoO 3 nanocomposite film was fabricated for H 2 S detection at room temperature. • Sample S4 (15 wt% oxide) showed a high response of ∼ 98.9 % at 50 ppm H 2 S with fast kinetics. • The sensor exhibited high selectivity over common interfering gases like CO, NH 3 , NO 2 , and SO 2 . • Excellent repeatability and stability were confirmed over eight cycles and 30 days. A novel PVA/PEO–CoO/MoO 3 nanocomposite was successfully fabricated and evaluated as a high-performance chemiresistive gas sensor for H 2 S detection at room temperature. Structural and morphological analyses confirmed the successful incorporation of uniformly dispersed CoO and MoO 3 nanoparticles into the polymer matrix, while electrical characterization demonstrated enhanced conductivity with increasing oxide content. Among the compositions tested, the film with 15 wt% metal oxide loading (Sample S4) showed optimal sensing performance, delivering a high response of ∼ 98.9 % to 50 ppm H 2 S, with fast and reversible dynamics and minimal signal drift. The sensor also exhibited excellent selectivity toward H 2 S over other interfering gases and maintained stable performance over repeated cycles and 30 days of storage. Compared with similar systems in the literature, the proposed sensor outperforms in terms of sensitivity, selectivity, and room-temperature functionality, without requiring external heating or complex fabrication methods. These findings highlight the potential of oxide–polymer hybrid systems for the development of low-cost, flexible, and scalable gas sensors for real-world applications.