Water scarcity and waste pollution are serious global challenges due to the rapid development

of the global economy and population growth. A win-win strategy to address the water crisis

and reduce pollution is to use waste materials as low-carbon and eco-friendly photothermal

materials for solar-driven desalination. Steel slag, an abundant industrial waste product, has

excellent thermal conductivity. Enhancing its light absorption and hydrophilicity could enable

the creation of efficient and economical solar seawater desalination devices. In this study, our

research introduces a 3D desalination device using this modified slag, achieving a consistent

evaporation rate fluctuating around 29 kg m-2 h-1 at 4 m s-1 wind speed for five days. This

breakthrouogh can be attributed to the excellent light-to-heat conversion of the modified steel

slag, coupled with the synergistic interaction between the porous evaporator and wind, culminating in efficient steam evaporation and diffusion. Life Cycle Analysis (LCA) reveals

that the carbon emissions of the modified steel slag for desalinating each ton of seawater are

only 2.20 kg CO2-eq, indicating superior prospects for carbon reduction compared to the reverse osmosis (RO) and Multi-Stage Flash Desalination (MSF) processes