Raspberry-Like Zn-Doped SnS Nanostructure for Ammonia Sensing at Room Temperature

Abstract

The raspberry-like Zn-doped SnS was achieved by a facile solvothermal method. The characteristics of its structure and morphology were determined by XRD, SEM and XPS. And the sensing properties to ammonia gas were tested at room temperature (22°C) and 40% relative humidity. The result demonstrated that the Zn-doped SnS exhibited better gas sensing properties for ammonia (567% - 50 ppm), which was 4.02 times higher than that of pure SnS. Also, the selectivity of the sensor was improved. For theoretical understanding of this sensing behavior, we carried out first-principles calculations based on density functional theory (DFT). The adsorption of gas molecules on pure SnS and Zn-doped SnS surfaces was simulated, the corresponding properties were calculated, and the sensing mechanism in the context of energy and electron density differences was further explored. This work validates that the synthesis of raspberry-like Zn-doped SnS presents a novel channel for the production of ammonia sensors with high-quality detection properties at room temperature, and the ammonia sensing mechanism is also investigated from the perspective of energy and electronics.