Dual-Functional Paper with Anti-Photodegradation and Acidification Resistance Enabled by Carbon Quantum Dots@Mg(OH) ₂ Nanocomposite

Paper-based cultural relics possess great historical and cultural value but are vulnerable to irreversible degradation from high-energy ultraviolet (UV) light exposure and acidification, threatening their long-term preservation. Current paper protection predominantly relies on exogenous materials with single functions, which not only provide limited protective effects but also pose a risk of secondary damage. In this study, we developed a Dual-Functional paper by directly integrating a carbon quantum dot–magnesium hydroxide (CQDs@Mg(OH)2) nanocomposite into the papermaking process, thereby endowing the paper with intrinsic resistance to both acidification and UV-induced photodegradation, which reduces the reliance on subsequent protective treatments and fundamentally enhances the paper’s longevity. The results demonstrate that the functional paper integrated with CQDs@Mg(OH)2 nanocomposites shows good structural compatibility and strong resistance to degradation. Under the conditions of both UV exposure and dry-heat aging, the functional paper demonstrates excellent resistance to photooxidative and acid-induced degradation, indicating its strong potential for extending the longevity of paper-based materials. Additionally, the fluorescent properties of CQDs reveal promising potential as optical anticounterfeiting markers. This work opens an avenue for the design of long-lasting functional paper enabled by carbon-based materials, with promising applications in the preservation of paper-based cultural heritage.