Reversible Zn2+-induced 3D self-assembled aerogel of carboxyl modified copper indium diselenide quantum dots: mechanism and application for inkjet printing anti-counterfeiting

Three-dimensional (3D) self-assembled quantum dot (QD) aerogels have attracted attention due to the combined properties of both QDs and porous materials. However, the difficulty and complexity of structural composition control limit the practical application of 3D self-assembled QDs. Hence, convenient, available and multifunction QD aerogels need to be explored to promote broader practical applications. Herein, we propose a universal and facile self-assembly method of copper indium selenium (CISe) QD aerogels based on coordination interaction between Zn²⁺ and carboxyl. Both experiments and Monte Carlo simulations indicate that QDs are aggregated into oligomers by Zn²⁺, and then the oligomers are gradually interconnected to each other to form a 3D network as the concentration of Zn²⁺ increases. Moreover, Zn²⁺-induced 3D self-assembled aerogel could be depolymerized by EDTA reversibly. In combination with CISe QDs, Zn-CISe aerogel has been successfully applied in green pollution-free environment-friendly anti-counterfeiting and encryption systems.