Room-Temperature NH3 Sensor Based on SnO2 Quantum Dots Functionalized SnS2 Nanosheets

Traditional metal oxide semiconductor gas sensors are facing significant challenges for portable devices and integration due to large power consumption caused by high working temperature. 2D nanomaterials with large specific surface areas, rich active sites, and tunable electrical properties are proved to be promising candidates for room-temperature gas sensors. However, several disadvantages including weak response, sluggish response/recovery kinetics, and poor selectivity still need to be overcome for high-performance gas sensors. Herein, SnO2 quantum dots (QDs) with a diameter of approximate to 3 nm functionalized SnS2 nanosheets with a thickness of approximate to 17 nm are synthesized via a two-step solvothermal method, which exhibits a high response of 11.1 to 100 ppm NH3 at room temperature of 25 degrees C with fast response speed and good repeatability, high selectivity, and long-term stability. The sensing mechanism is mainly ascribed to 0D/2D heterostructure, synergistic effect, and n-n heterojunction constructed across the interfaces between SnO2 QDs and SnS2 nanosheets. The as-prepared nanomaterials may contribute to the reasonable design of heterostructure between 0D QDs and 2D nanomaterials, and offer a promising candidate for room-temperature NH3 detection.