In-doped SnS2 induced S-vacancies for ammonia-sensitive sensors

In this study, In-doped SnS₂ nanostructures were synthesized by a one-step hydrothermal method. Characterization results demonstrated that S vacancies were successfully constructed in the synthesized material. Samples doped with different masses of indium were prepared. Among them, the In/V_s2-SnS₂ sample with moderate sulfur vacancy content showed the best ammonia detection response (500 ppm) at room temperature, and the peak response reached 2392. Moreover, the sensor exhibited a response/recovery time of 37.5s/3.3s. The adsorption energies of ammonia on the pure phase SnS₂ surface and S vacancies sample were determined by the first principle DFT calculations. The theoretical analysis agreed well with the experimental results, suggesting that the S vacancies provided more active sites for effective adsorption, favoring the sensitive detection of ammonia molecules. The proposed study demonstrates that In-doping created S vacancies in SnS₂, which is promising for gas sensitization, laying the foundation for high-performance room-temperature gas sensors.