Rational Design of Nanoporous MoS2/VS2 Heteroarchitecture for Ultrahigh Performance Ammonia Sensors

2D transition metal dichalcogenides (TMDs) have received widespread interest by virtue of their excellent electrical, optical, and electrochemical characteristics. Recent studies on TMDs have revealed their versatile utilization as electrocatalysts, supercapacitors, battery materials, and sensors, etc. In this study, MoS2 nanosheets are successfully assembled on the porous VS2 (P-VS2) scaffold to form a MoS2/VS2 heterostructure. Their gas-sensing features, such as sensitivity and selectivity, are investigated by using a quartz crystal microbalance (QCM) technique. The QCM results and density functional theory (DFT) calculations reveal the impressive affinity of the MoS2/VS2 heterostructure sensor toward ammonia with a higher adsorption uptake than the pristine MoS2 or P-VS2 sensor. Furthermore, the adsorption kinetics of the MoS2/VS2 heterostructure sensor toward ammonia follow the pseudo-first-order kinetics model. The excellent sensing features of the MoS2/VS2 heterostructure render it attractive for high-performance ammonia sensors in diverse applications.