Facile synthesis of halloysite nanotubes-based nanocomposite with room-temperature phosphorescence properties

The development of new nanocomposites with room-temperature phosphorescence properties is a hot issue in diverse fields. Halloysite nanotubes (HNTs), a natural product, have the advantages of low cost, low toxicity and easy surface modification, making them an ideal substrate for constructing new functional nanocomposites. In this study, polyacrylamide-grafted halloysite nanotubes (HNTs-Poly) and 2,4,6-tris(4-bromophenyl)-1,3,5-triazine (TBPT) were used as the starting materials to prepare a composite carbon dot material (HNTs-TBPT) via an in-situ solvent-free reaction. The reaction was carried out via solid-phase synthesis with simple operation. Characterizations including Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) confirmed that the product structure was consistent with the expected design. HNTs-TBPT exhibited a fluorescence emission peak at 500 nm with a visible yellow fluorescence, and its phosphorescence lifetime reached 266 ms. The synthesis of these carbon dots provides a new idea for the design and preparation of inorganic-organic composite luminescent materials, and is expected to have promising applications in encrypted storage, anti-counterfeiting marking, encrypted thermal printing, flexible optoelectronic devices and other fields.