Design of NiO–ZnCo2O4 heterostructures for room temperature H2S sensing

Hydrogen sulfide (H₂S) detection with novel sensing properties such as higher response and minimum detection limit at room temperature is essential to ensure the safety of humans and the environment. A hydrothermal method was utilized to synthesize NiO–ZnCo₂O₄ heterostructures. The purpose of these materials was to fabricate gas sensors and detect different hazardous gases. The intrinsic properties of synthesized products were studied to check the microstructure and morphological properties of the heterostructures. Different gas sensors performed gas sensing properties, and the significant properties such as high response (ratio of response in gas and response in air $R_g∕R_a=290$) towards 20$$ppm H₂S, short response/recovery time (32/20 s), a low detection limit (0.5 ppm), and great selectivity were detected based on the gas sensor of NZCO-5 (5% NiO–ZnCo₂O₄) compared with other sensors NiO, NZCO-0 (0% NiO–ZnCo₂O₄) and NZCO-10 (10% NiO–ZnCo₂O₄). The significant H₂S gas sensing improvement in this study could be a potential route for saving human lives.