Large‐Scale Synthesis of Flexible, Stable, and Transparent MoS₂ Quantum Dots‐Polyvinyl Alcohol Sensing Film

Abstract The transparent light emitting molybdenum disulfide quantum dots‐polyvinyl alcohol (MoS₂ QDs‐PVA) polymer composite film with high optical performance is fabricated through a drop‐coating method. Particularly, the functional composite film possesses good transparency and flexibility, and it can be easily rolled into any shape. Moreover, the film shows mechanical stability, stretchability, and high thermal and storage stability. Importantly, the values of pH can be imparted directly by the fluorescence color changes of the MoS₂ QDs‐PVA film without the further complex instruments, and the MoS₂ QDs‐PVA film has a good reproducibility of pHs. The pH test paper is also utilized for visual sensing of pH in the bacterial culture solution, and satisfactory results are obtained. It is believed that the transparency and foldable light‐emitting MoS₂ QDs‐PVA polymer composite film can bring a bright prospect in the field of development of functional films emitting various fluorescent colors, and they have great potential applications in the sensing area.