Ecofriendly chitosan-derived carbon aerogels based eutectic hydrated salts for good solar thermal energy storage and corrosion mitigation effect

• Good solar thermal energy storage and corrosion mitigation effect are integrated. • The supercooling can be efficiently decreased without additional nucleating agents. • Excellent photothermal conversion and thermal reliability is practical. Emerging integrated latent heat storage and photothermal conversion have great potential to efficiently capture solar light and facilitate energy management. However, the energy conversion performances and application prospects are limited by poor solar absorption and corrosion effects of phase change materials (PCMs), especially hydrated salts. Here, eutectic hydrated salt is proposed for integration of practical solar thermal energy storage and corrosion mitigation effect. We design a facile method to formulate porous chitosan-based carbon aerogels with robust structure and orientated network by freeze-drying and carbonization processes. After impregnation with MgCl 2 ·6H 2 O-NH 4 Al(SO 4 ) 2 ·12H 2 O eutectics, effective corrosion mitigation effect, enhanced thermal conductivity of 0.77 W/mK, and high energy storage density of up to 214.8 J/g are demonstrated simultaneously. The eutectic PCMs show photothermal conversion efficiency as high as 89.5 %, attributing to the synergistic effect of the molecular thermal vibrations of carbon nanomaterials and the local surface plasmon resonance (LSPR) effect of ZrC nanomaterials. This work creates a new avenue for high-efficiency solar energy storage and mitigating corrosion effect based on eutectic hydrated salts.