Boosting room-temperature NO detection via in-situ interfacial engineering on AgS/SnS heterostructures.

The effective detection of hazardous gases has become extremely necessary for the ecological environment and public health. Interfacial engineering plays an indispensable role in the development of innovative materials with exceptional properties, thus triggering a new revolution in the realization of high-performance gas sensing. Herein, the rational designed AgS/SnS heterostructures were synthesized via a facile in-situ cation-exchange method. The coshared S atoms derived from in-situ interfacial engineering enable intimate atomic-level contact and strong electron coupling between SnS and AgS, which efficiently assist interfacial charge redistribution and transport as confirmed theoretically and experimentally. Benefiting from the high-quality interface of the heterostructures, the resultant AgS/SnS sensor delivered an ultrahigh response (286%) together with short response/recovery time (17 s/38 s) to 1 ppm NO. The sensor also demonstrated superior sensing selectivity and reliable repeatability at room-temperature. Such excellent sensing performance could be synergistically ascribed to the junction effect and interfacial engineering of AgS/SnS heterostructures, which not only modulates the electronic properties of SnS but also provides abundant adsorption sites for gas sensing. This study offers guidance for engineering heterostructures with high-quality interface, which might stimulate the exploitation of other novel materials and widen their potential applications.