Cerium-doped zinc oxide anchored halloysite nanoclays as skin management system for photoprotection and radiative cooling

Sunscreens are crucial for skin health by protecting against the harmful effects of ultraviolet (UV) radiation. To overcome persistent limitations of irritation and discomfort in existing formulations, a high-performance radiative cooling sunscreen, CZHR, has been strategically designed. This formulation synergistically integrates cerium-doped zinc oxide (Ce-ZnO) and halloysite nanotubes (HNTs) to achieve dual UV protection and skin cooling. As a nanocarrier, HNTs effectively regulate the particle size, morphology, and oxygen vacancies of Ce-ZnO, significantly enhancing UV protection and catalytic activity. Resveratrol is further incorporated to improve UV resistance and pathogen inhibition. The resulting CZHR-based Pickering emulsion exhibits excellent UV shielding, high solar reflectance (0.73), and infrared emissivity (0.87). In vitro and in vivo tests show efficacy in alleviating UV-induced cellular damage and inhibiting biofilm formation. Notably, compared to commercial products, the CZHR sunscreen reduces skin temperature by an additional 1.7–2.9 °C. Biosafety evaluation confirms non-irritating property and negligible skin penetration. This thermal management system represents a promising platform for advanced photoprotection and radiative cooling.