Cu₈S₅/PDA@SA Hydrogel: A Synergistic Photothermal and Photocatalytic Approach for Efficient Solar Steam Sterilization

Solar absorbers play a crucial role in interfacial solar steam generation (ISSG) technology, facilitating efficient steam generation and sterilization. Nonetheless, limitations in solar conversion efficiency and water transport effects, coupled with challenges in outdoor portability of traditional installations, have hindered the progress in steam sterilization technology. In this work, based on Cu8S5/PDA nanoparticles (NPs) and sodium alginate (SA) hydrogel, a solar steam sterilization absorber with superior photothermal conversion and antibacterial properties was developed. The Cu8S5/PDA@SA hydrogel synthesized via in situ deposition demonstrated remarkable full-spectrum absorption performance and stable photothermal conversion ability (37.56%), capable of effectively destroying bacterial structure and metabolic functions through multiple therapeutic mechanisms: photothermal therapy via thermal effect of high temperature and chemodynamic and photodynamic therapies via oxidation of reactive oxygen species and depletion of intracellular glutathione, achieving 100% steam antibacterial efficiency and presenting excellent antibacterial potential under low irradiation conditions. This study proposes a promising avenue for the development of environmentally friendly and easy-to-use solar steam sterilizers for off-grid conditions.