ABSTRACT Efficient and scalable solar evaporation systems are critical for sustainable seawater desalination and brine resource recovery. However, conventional strategies face material integration constraints: materials must simultaneously perform solar absorption, fluid transport, and evaporation functions. This coupling struggles to balance high evaporation rates with continuous salt harvesting, limiting long‐term stability, and overlooks the potential of sidewall evaporation in 3D architectures. Here, we introduce a bottom‐heated 3D solar convective evaporator (SCE) that spatially decouples the heating and evaporation processes. This design leverages bottom photothermal heating to induce natural convection, thereby enhancing sidewall heating and promoting efficient vapor removal. Through this synergy, the SCE achieves an 82.8% higher evaporation rate than 2D designs under the same solar‐heated area at a pillar height of only 3× the radius and outperforms conventional 3D systems in lab conditions once the heating radius exceeds 2× the pillar radius. Importantly, this decoupled architecture also confines salt precipitation to the base rather than the evaporation surface, enabling continuous operation in seawater and hypersaline brines up to 17.5 wt.%. This work demonstrates a simple and scalable approach to high‐efficiency solar desalination and hypersaline brine management.
Ma et al. (Mon,) studied this question.