Highly Sensitive Room Temperature H₂S Gas Sensor Based on the Nanocomposite of MoS₂-ZnCo₂O₄

The stacking 2D materials, such as molybdenum disulfide (MoS₂), are among the most promising candidates for detecting H₂S gas. Herein, we designed a series of novel nanocomposites consisting of MoS₂ and ZnCo₂O₄. These materials were synthesized via a simple hydrothermal method. The microstructure and morphology of nanocomposites were studied by different characteristics such as X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy. These nanocomposites were used as gas sensors, and the highest response (6.6) toward 10 ppm of H₂S was detected by the gas sensor of MZCO-6 (having MoS₂ contents 0.060 g) among all other tested sensors. The response value (R_a/R_g) was almost three times that of pure ZnCo₂O₄ (R_a/R_g = 2). In addition, the sensor of MZCO-6 exposed good selectivity, short response/recovery time (12/28 s), long-term stability (28 days), and a low detection limit (0.5 ppm) toward H₂S gas at RT. The excellent performance of MZCO-6 may be attributed to some features of MoS₂, such as stack structure, higher BET and surface area and active sites, a synergistic effect, etc. This simple fabrication sensor provides a novel idea for detecting H₂S gas at RT.