SnS2/Ti3C2Tx hybrids for conductometric triethylamine detection at room temperature

Transition metal carbides/nitrides (MXenes) and transition metal dichalcogenides (TMDs) have received much attention for gas sensors due to their large surface area, versatile surface chemistry, and unique gas detection capability. With distinct electrical conductivity and abundant surface chemical groups, titanium carbide (Ti3C2Tx) displays great potential in detecting volatile organic compounds (VOCs) at room-temperature. As a TMD with large electronegativity, tin disulfide (SnS2) is advantageous to outstanding sensing performance. Still, the poor intrinsic conductivity and slow response/recovery speeds impede their applications in room-temperature (RT) gas sensors. Herein, SnS2 nanoflakes were integrated with Ti3C2Tx skeleton platforms as the sensitive channels for VOC detection. The normalized response of the SnS2/Ti3C2Tx sensor was 38% to 50 ppm triethylamine (TEA) at RT, and the sensitivity at 2-20 ppm TEA was 1.2% ppm-1. Moreover, SnS2/Ti3C2Tx sensor exhibited fast response/recovery times of 12/8.5 s, a theoretical LOD of 0.49 ppm, excellent selectivity, and reliable long-term stability. The superior sensing performance is attributed to the formed heterojunctions and the unique microstructures of SnS2/Ti3C2Tx hybrids. These achievements of the heterostructured SnS2/Ti3C2Tx sensors demonstrate a novel strategy to realize effective VOC detection at RT.