Inverse‐L Shaped Evaporator Based on La _1−x Sr _x MnO ₃ Perovskite with Efficient Salt Collection via Localized Salt Gradient

Abstract Solar desalination offers a sustainable solution for freshwater production with minimal carbon emissions by utilizing solar energy. However, the efficiency of solar‐vapor generation is often limited due to its high energy demands, resulting in low water evaporation rates under natural sunlight. To overcome this challenge, La _0.7 Sr _0.3 MnO ₃ , an oxide perovskite is introduced that acts as a highly efficient photothermal material. It effectively converts solar energy into heat by forming intra‐band trap states, which facilitate non‐radiative recombination of photoexcited electrons and holes, thereby enhancing heat release through thermalization. A key obstacle in solar desalination is salt accumulation, which can degrade material performance over time. To mitigate this, a novel device design is developed that enables one‐directional fluid flow, establishing a salt gradient that pushes salt to the edges of the photothermal material, significantly reducing fouling and light shielding. By combining La _0.7 Sr _0.3 MnO ₃ with this innovative design, an impressive solar evaporation rate of 3.40 kg m⁻ ² h⁻¹ under one sun is achieved, while ensuring strong antifouling capabilities in complex environments. This work demonstrates a breakthrough approach to enhancing the efficiency and durability of solar desalination through advanced material engineering and smart design.