H₂S/Butane Dual Gas Sensing Based on a Hydrothermally Synthesized MXene Ti₃C₂T_x/NiCo₂O₄ Nanocomposite

Real-time sensing of hydrogen sulfide (H₂S) at room temperature is important to ensure the safety of humans and the environment. Four kinds of different nanocomposites, such as MXene Ti₃C₂T_x, Ti₃AlC₂, WS₂, and MoSe₂/NiCo₂O₄, were synthesized using the hydrothermal method in this paper. Initially, the intrinsic properties of the synthesized nanocomposites were studied using different techniques. P-type butane and H₂S-sensing behaviors of nanocomposites were performed and analyzed deeply. Four sensor sheets were fabricated using a spin-coating method. The gas sensor was distinctly part of the chemiresistor class. The MXene Ti₃C₂T_x/NiCo₂O₄-based gas sensor detected the highest response (16) toward 10 ppm H₂S at room temperature. In comparison, the sensor detected the highest response (9.8) toward 4000 ppm butane at 90 °C compared with the other three fabricated sensors (Ti₃AlC₂, WS₂, and MoSe₂/NiCo₂O₄). The MXene Ti₃C₂T_x/NiCo₂O₄ sensor showed excellent responses, minimum limits of detection (0.1 ppm H₂S and 5 ppm butane), long-term stability, and good reproducibility compared with the other fabricated sensors. The highest sensing properties toward H₂S and butane were accredited to p-p heterojunctions, higher BET surface areas, increased oxygen species, etc. These simply synthesized nanocomposites and fabricated sensors present a novel method for tracing H₂S and butane at the lowest concentration to prevent different gas-exposure-related diseases.