H 2 S/Butane Dual Gas Sensing Based on a Hydrothermally Synthesized MXene Ti 3 C 2 T x /NiCo 2 O 4 Nanocomposite.

Real-time sensing of hydrogen sulfide (H2 S) at room temperature is important to ensure the safety of humans and the environment. Four kinds of different nanocomposites, such as MXene Ti3 C2 Tx , Ti3 AlC2 , WS2 , and MoSe2 /NiCo2 O4 , 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 H2 S-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 Ti3 C2 Tx /NiCo2 O4 -based gas sensor detected the highest response (16) toward 10 ppm H2 S 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 (Ti3 AlC2 , WS2 , and MoSe2 /NiCo2 O4 ). The MXene Ti3 C2 Tx /NiCo2 O4 sensor showed excellent responses, minimum limits of detection (0.1 ppm H2 S and 5 ppm butane), long-term stability, and good reproducibility compared with the other fabricated sensors. The highest sensing properties toward H2 S 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 H2 S and butane at the lowest concentration to prevent different gas-exposure-related diseases.