Smart Strategies for Light and Thermal Management in High-Efficiency Solar Steam Generation

Solar steam generation (SSG), a solar-driven water purification technology based on ultrablack photothermal materials (PTMs) and sunlight, has attracted wide attention around the world. That is because SSGs can obtain pure water without consuming fossil energy to alleviate the shortage of drinking water around the world. So far, scientists have made many ingenious designs to improve the comprehensive performance of evaporators. Based on the structural design of PTMs, the light and thermal management strategies involved in SSGs are comprehensively summarized and discussed herein. Light management strategies include intrinsic light absorption and enhanced light absorption through structure designs of different scales to reduce reflected energy loss. Thermal management strategies include reducing conduction, radiation, convective heat loss, and even capture heat from the warm ambient for water evaporation. Using these strategies to carry out careful structure designs, the evaporators can achieve high evaporation rates and efficiencies close to or above the theoretical values. Prospects for the development of SSGs and the urgent problems that need to be solved are discussed. It is expected that this review guides researchers in exploring the fundamentals and design strategies of SSG and further guides device optimization.