Highly Flexible and Efficient Solar Steam Generation Device

Abstract

Solar steam generation with subsequent steam recondensation has been regarded as one of the most promising techniques to utilize the abundant solar energy and sea water or other unpurified water through water purification, desalination, and distillation. Although tremendous efforts have been dedicated to developing high-efficiency solar steam generation devices, challenges remain in terms of the relatively low efficiency, complicated fabrications, high cost, and inability to scale up. Here, inspired by the water transpiration behavior of trees, the use of carbon nanotube (CNT)-modified flexible wood membrane (F-Wood/CNTs) is demonstrated as a flexible, portable, recyclable, and efficient solar steam generation device for low-cost and scalable solar steam generation applications. Benefitting from the unique structural merits of the F-Wood/CNTs membrane-a black CNT-coated hair-like surface with excellent light absorbability, wood matrix with low thermal conductivity, hierarchical micro- and nanochannels for water pumping and escaping, solar steam generation device based on the F-Wood/CNTs membrane demonstrates a high efficiency of 81% at 10 kW cm , representing one of the highest values ever-reported. The nature-inspired design concept in this study is straightforward and easily scalable, representing one of the most promising solutions for renewable and portable solar energy generation and other related phase-change applications.

Harnessing Solar‐Driven Photothermal Effect toward the Water–Energy Nexus

“…Due to strong absorption property (up to 98% in visible and near-infrared region) [60] and high thermal conductivity (6000 W m −1 k −1 ), [72] these CNT-based photothermal convertors can not only efficiently generate a lot of thermal energy, but also fast transfer thermal energy into surrounding medium via radiation and conduction method. These increased conjugated π bonds will result in a red-shift of the absorption light spectrum, which greatly benefits in the solar energy utilization efficiency.…”

“…[41,60,70,71,138] Thanks to this unique structure, woodbased evaporator exhibited a higher water evaporation rate (1.31 kg m −2 h −1 ) than that of porous membrane-based evaporator (0.75 kg m −2 h −1 ) under simulated 1 sun illumination. Theoretically, for the same thickness and channel size, the vertical channels possess much higher water transport rate than the tortuous channels, due to their shorter transport pathway and lower transport barrier.…”

Fast‐Growing Field of Interfacial Solar Steam Generation: Evolutional Materials, Engineered Architectures, and Synergistic Applications

“…The wood is covered with carbon nanotubes/graphite/different plasmon nanoparticles. Reproduced with permission . Copyright 2017, copyright 2017, copyright 2018, Wiley‐VCH.…”

“…Compared with the raw wood, PDA‐coated wood not only enhances the optical absorption capacity, but also increases the hydrophilicity and facilitates the transportation of water. Besides, Hu et al coated a series of carbon‐based materials (carbon nanotube (CNT) powder and graphite) and plasmonic materials (Pd, Au, Ag) on wood and obtained ISSG device (Figure b). The as‐fabricated CNT/graphite/Pd‐modified wood‐based ISSG device exhibits an evaporation efficiency of above 80% upon exposure to sunlight with an intensity of 1 and 10 kW m −2 .…”

Novel Receiver-Enhanced Solar Vapor Generation: Review and Perspectives

“…It is found that this capability of high solar steam generation is attributed to the unique natural structure of mushroom, umbrella-shaped black pileus, porous context, and fibrous stipe with a small cross section [110]. Inspired by the water transpiration behavior in trees through xylem from roots to the leaves surface, carbon nanotube coated balsa wood [111], flame coated wood [112], and graphene oxide coated wood [113], demonstrated an efficiency of 81, 72, and 83% at solar irradiance of 10, 1, and 12 kW m −2 , respectively. Thermal conductivities of and solar thermal conversion efficiency of various materials under 1 sun solar irradiance are tabulated in Table 1.…”