Bright green phosphorescent carbon dots prepared from natural vitamins for information encryption

Materials with room temperature phosphorescence (RTP) have long lifetimes and large Stokes shifts, making them excellent candidates for bioimaging, anticounterfeiting, and encryption applications. As a metal-free RTP material, carbon dots (CDs), have received considerable attention. Using vitamin B9 (V) and ethylenediamine (EDA) as raw materials, blue fluorescent VCDs are synthesized by a one-step hydrothermal process in our study. A boric acid (BA) matrix is then used to embed the CDs, and VCDs@BA is prepared as an environmentally friendly and economical RTP material. Bright blue fluorescence and vivid green phosphorescence are released by VCDs@BA. The phosphorescence may last up to 6.0 s and has a lifespan of 311 ms. The photoluminescence quantum yield of the material is as high as 11.03%. VCDs@BA has been utilized effectively in applications for information security and anti-counterfeiting because of its optic property. This research offers a sustainable method for the synthesis of RTP materials, which is a feasible way to create room-temperature phosphorescent materials with excellent efficacy and prolonged afterglow durations.