Growth of MoS₂–MoO₃ Hybrid Microflowers via Controlled Vapor Transport Process for Efficient Gas Sensing at Room Temperature

Abstract

Abstract A nucleation controlled one‐step process to synthesize MoS 2 –MoO 3 hybrid microflowers using vapor transport process and its application in efficient NO 2 sensing at room temperature are reported. The morphology and crystal structure of the microflowers are characterized by scanning electron microscope (SEM), Raman, X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy techniques. A cathodoluminence mapping reveals that the core of the microflower consists of MoO 3 , and the flower petals as well as nanosheet are composed of a few layers of MoS 2 . Further, the MoS 2 –MoO 3 hybrid microflower sensor exhibits a high sensitivity of ≈33.6% with a complete recovery to 10 ppm NO 2 at room temperature without any extra stimulus like optical or thermal source. Unlike many earlier reports on MoS 2 sensor, this advanced approach shows that the sensor is exhibited a low response time (≈19 s) with complete recovery at room tepmerature and excellent selectivity toward NO 2 against various other gases. The efficient conventional sensing of the sensor is attributed to a combination of high hole injection from MoO 3 to MoS 2 and modulation of a potential barrier at MoS 2 –MoO 3 interface during adsorption/desorption of NO 2 . It is believed that the modified properties of MoS 2 by such composite could be used for various advanced device applications.