UV and high-energy blue light absorbing carbon quantum dot films for preventing the fading of dyed cultural relics

Yellow-emissive carbon quantum dots were fabricated via one-pot hydrothermal method with base-catalyzed molecular fusion • YCQDs@PVA films enable strong absorption of 200–460 nm light, blocking photon energy inducing dye chromophore degradation • Elucidates the fading of dyed cultural relics and the protective mechanism of YCQDs@PVA films at the molecular level • Films exhibit high light-shielding efficiency, biocompatibility, and flexibility for non-invasive heritage protection As essential components of cultural heritage, dyed artifacts preserve valuable historical information. However, the inherent instability of natural dyes makes their long-term preservation challenging, as they are highly susceptible to photodegradation and oxidative damage, leading to fading and loss of cultural value. In this work, yellow-emissive carbon quantum dots (YCQDs) with an emission peak at 550 nm were synthesized via a one-pot hydrothermal method using a base-catalyzed molecular fusion strategy. The YCQDs exhibited strong absorption in the ultraviolet (UV, 200–400 nm) and high-energy blue light (HEBL, 400–460 nm) regions, effectively shielding dyes from light-induced damage. YCQDs were further incorporated into polyvinyl alcohol (PVA) to form YCQDs@PVA composite films, which were applied to gardenia-dyed paper colored with a representative natural dye. The films displayed excellent protection under UV, white LED and blue LED aging conditions. Ultraviolet-visible (UV–Vis) absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and liquid chromatography-mass spectrometry (LC-MS) analyses revealed the main chromophores of gardenia yellow and further elucidated that the YCQDs@PVA films effectively suppressed oxidative cleavage and cis-trans isomerization of conjugated double bonds. This study proposes a novel strategy for employing carbon quantum dots for the long-term preservation of dyed cultural relics, highlighting the promising potential of nanocomposite materials in heritage conservation. Download: Download high-res image (174KB) Download: Download full-size image