Water heating and disinfection with reduced energy and CO₂ footprint demands new and efficient materials for solar-thermal conversion technologies. Here, we demonstrate nanostructured porous hard-carbon florets (NCF) as effective solar absorber coating achieving excellent photon thermalization efficiency (87%). Functional NCF coating on three-dimensionally tapered helical solar receivers generate high surface temperatures (up to 95 °C). Such ‘green-heat’ is channeled to heat water up to 82 °C that simultaneously results in water disinfection through thermal shock. Untreated lake-water with high turbidity (5 NTU), high bacterial load (10⁶ CFU mL⁻¹) and pathogenic fungi is effectively disinfected in a continuous flow process. Translating this, a fully automated SWAP prototype (solar water antimicrobial purifier), delivers bacteria free hot water at an output capacity of 42 L m⁻² day⁻¹ with the lowest CO₂ footprint (5 kg L⁻¹) in comparison to all other existing approaches (>40 kg L⁻¹).

_{减少能源和CO 2}足迹的水加热和消毒需要用于太阳能热转换技术的新型高效材料。在这里，我们展示了纳米结构多孔硬碳小花（NCF）作为有效的太阳能吸收涂层，可实现出色的光子热化效率（87％）。三维锥形螺旋太阳能接收器上的功能性 NCF 涂层会产生很高的表面温度（高达 95 °C）。这种“绿热”可将水加热至 82°C，同时通过热冲击对水进行消毒。未经处理的高浊度（5 NTU）、高细菌负荷（10 ⁶ CFU mL ^-1）和病原真菌的湖水在连续流动过程中得到有效消毒。换言之，全自动 SWAP 原型（太阳能水抗菌净化器）可提供无菌热水，输出能力为 42 L m ⁻² day ⁻¹ ，与所有产品相比， CO ₂足迹最低（5 kg L ⁻¹ ）。其他现有方法（>40 kg L ^-1）。