Synthesis of Waste Paper-Derived Carbon Dots and Their Application in Anti-Counterfeiting

In recent decades, global paper production has continuously increased, but large amounts of the resulting waste paper have not been effectively recycled, posing a serious threat to the environment and sustainable development. Regarding the above issues, this study successfully synthesized waste paper-based carbon dots (WP-CDs) with excellent optical properties and eco-friendliness using a one-step hydrothermal method with waste paper as the carbon source. When WP-CDs are dispersed into polyvinyl alcohol (PVA) matrix and dried, the resulting WP-CDs@PVA composite exhibits not only blue fluorescence (FL) at 430 nm but also room-temperature phosphorescence (RTP) at 530 nm, with a phosphorescence lifetime of 217.7 ms. Based on this dual-mode emission characteristic, the material shows great potential for anti-counterfeiting inks and fluorescent flexible films. This study not only achieved high-value utilization of waste paper but also provided a feasible approach for developing green, low-cost anti-counterfeiting materials.