Solar Interface Evaporation System Assisted by Mirror Reflection Heat Collection Based on Sunflower Chasing the Sun

In this study, a photothermal material, C-CP/MnO2, was prepared by compounding corrugated paper (CP) and MnO2, with excellent photothermal conversion efficiency. The porous structure and the presence of oxygen-containing functional groups enabled the material to have a good water transport function and a fast vapor escape rate. The special semihollow structure also allowed C-CP/MnO2 to have better thermal management and an evaporation rate that could reach 2.563 kg m–2 h–1 with an efficiency of 98.82% under 1 sun. The continuous arch structure inside C-CP/MnO2 was able to induce the Marangoni effect to achieve continuous desalination of high-concentration brine. The mirror heat collector achieved efficient light capture on the material surface through multiple reflections of light. This could increase the amount of radiation on the material surface by nearly 80%, and the evaporation rate could reach 4.314 kg m–2 h–1 under 1 sun. Moreover, this study demonstrated the light propagation path by simulating the light using Zemax to verify the correctness of the experimental results. Inspired by the sunflower chasing the sun, we designed a chasing heat collection system powered by solar panels to achieve efficient evaporation outdoors. This provided new ideas for further development of solar interface evaporation and also provided guidance for other industrial applications.