Solar steam generation has been emerged as one of efficient and green technologies for harvesting solar energy for seawater desalination and wastewater treatment. Herein, we demonstrate a facile approach for scalable fabrication of phenolic aldehyde foams (PAFs), which were synthesized by polymerization of formaldehyde with phenol and hydroquinone through one-step hydrothermal method, as double layered photothermal materials for efficient solar steam generation. The resulting PAFs show high porosity of higher than 93.6%, low apparent density (0.152–0.167 g cm⁻³), low thermal conductivity (0.034–0.054 W m⁻¹ k⁻¹) and a good mechanical strength (0.07 MPa under 30% strain). The presence of close-packed open channels, by combination with their surface superhydrophilicity (water contact angle ~ 0°), ensure the PAFs a rapid transportation of water molecules. After facile coating a thin layer of carbon soot on PAFs, a double layered photothermal materials with enhanced light absorption (~90%) was fabricated (named as CPAFs). Under 1 sun irradiation, the CPAFs possess a high water evaporation rate of 1.4922 kg m⁻² h⁻¹ and a solar conversion efficiency of 87.86%, making it promising candidate as solar generators for efficient solar desalination. By combining with their simple, scalable and cost-efficient manufacture process, it is suggested that such CPAFs may have great potentials for real applications.

太阳能蒸汽发电已经成为一种有效的绿色技术，用于收集太阳能以进行海水淡化和废水处理。本文中，我们展示了一种可扩展制造酚醛泡沫（PAFs）的简便方法，该酚醛泡沫是通过甲醛与苯酚和对苯二酚通过一步水热法聚合而合成的，作为双层光热材料，可有效地产生太阳能蒸汽。生成的PAF的孔隙率高于93.6％，表观密度低（0.152-0.167 g cm ^-3），导热系数低（0.034-0.054 W m ^-1  k ^-1）和良好的机械强度（在30％应变下为0.07 MPa）。紧密堆积的明渠的存在，加上其表面的超亲水性（水接触角约为0°），可确保PAFs快速运输水分子。在PAF上轻松涂上一层薄薄的碳烟之后，就制成了具有增强的光吸收率（〜90％）的双层光热材料（称为CPAF）。在1次阳光照射下，CPAF具有高达1.4922 kg m ^-2  h ^-1的高水分蒸发速率太阳能转换效率高达87.86％，使其有望成为高效太阳能脱盐的太阳能发电设备。通过结合其简单，可扩展且具有成本效益的制造过程，建议此类CPAF在实际应用中可能具有巨大潜力。