To meet challenges of the global energy crisis and the freshwater resources shortage, the interfacial solar-to-steam conversion (ISSC) system was developed quickly in recent years. The photothermal materials play an important role in the ISSC system. We are devoted to developing a unique photothermal material integrating multiple 3D design philosophy both at macroscopic and microscopic levels by employing the cost-effective and widespread resources like straw, rose and coffee grounds, for carbonization as solar absorbers. The biomass-based carbonized particles (CPs) possess three major advantages: (1) wide size-distribution is accessible to form 3D porous rough surface of absorber layer to enhance ability of light absorption; (2) the pristine hierarchical microstructure could absorb nearly all the incident light; (3) the intrinsic vascular bundles with pores on their lumen walls provide a rapid and omnidirectional transport for water and steam escape. A high-efficient solar steam device was fabricated based on the absorber material with its internal 3D micro textures and external 3D architectures. Under the illumination of 1 sun, the photothermal conversion efficiency of straw, rose and coffee CPs can reach 93.4 %, 92.8 % and 76 %, respectively. Simultaneously, a high-efficient solar thermoelectric generator (STEG) is made by coating CPs on a commercial thermoelectric generator and the maximum power of STEG can reach 538.0 μW. Such scalable biomass-based photothermal materials and high-grade thermoelectric conversion capability could be applied to the water purification and the electricity production.

为了应对全球能源危机和淡水资源短缺的挑战，近年来，太阳能到蒸汽的界面转换（ISSC）系统得到了快速发展。光热材料在ISSC系统中起着重要作用。我们致力于通过利用具有成本效益的广泛资源（如稻草，玫瑰和咖啡渣）碳化作为太阳能吸收体，从而开发一种在宏观和微观层面上整合了多种3D设计理念的独特光热材料。基于生物质的碳化颗粒（CPs）具有三个主要优点：（1）可以达到较宽的尺寸分布，从而形成吸收层的3D多孔粗糙表面，以增强光吸收能力；（2）原始的分层微结构几乎可以吸收所有入射光；（3）管腔壁上有孔的固有血管束为水和蒸汽的逸出提供了快速，全方位的运输。基于吸收器材料及其内部3D微纹理和外部3D体系结构，制造了一种高效的太阳能蒸汽设备。在1个太阳光下，秸秆，玫瑰和咖啡CP的光热转化效率分别达到93.4％，92.8％和76％。同时，通过在商用热电发电机上涂覆CP制成高效太阳能热电发电机（STEG），STEG的最大功率可达到538.0μW。这种可扩展的基于生物质的光热材料和高等级的热电转换能力可以应用于水净化和电力生产。