2D WS2-Edge Functionalized Multi-Channel Carbon Nanofibers: Effect of WS2 Edge-Abundant Structure on Room-Temperature NO2 Sensing
Transition metal dichalcogenides (TMDs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) have been actively studied in recent years due to wide range of potential applications. As promising applications, TMD gas sensors have been developed and intensively explored. More recently, it has been reported that edge sites of TMDs can contribute to highly enhanced gas adsorption properties. Herein, superior room temperature gas sensing properties of WS2 edge functionalized carbon nanofibers (CNFs) with multiple tubular pores (WS2@MTCNFs) were firstly demonstrated. Copolymer-electrospinning route, which uses poly(styrene-acrylonitrile) as sacrificial templates and WS2 precursor contained poly(acrylonitrile) as carbon matrix, offers facile synthesis of CNFs having high gas permeability with single-layered WS2 edge-rich surface. As a result, WS2@MTCNFs based sensors exhibits noticeable gas response (15% at 1 ppm of NO2) at room temperature compared to the pristine CNFs (2% at 1 ppm of NO2), which is attributed to the synergistic effects originated from enhanced surface area and open porosity with numerous elongated pore channels of MTCNFs as well as remarkably increased active spots on the surface from WS2 edge sites.