Scalable and Highly Efficient Mesoporous Wood‐Based Solar Steam Generation Device: Localized Heat, Rapid Water Transport

Abstract

Solar steam generation is regarded as one of the most sustainable techniques for desalination and wastewater treatment. However, there has been a lack of scalable material systems with high efficiency under 1 Sun. A solar steam generation device is designed utilizing crossplane water transport in wood via nanoscale channels and the preferred thermal transport direction is decoupled to reduce the conductive heat loss. A high steam generation efficiency of 80% under 1 Sun and 89% under 10 Suns is achieved. Surprisingly, the crossplanes perpendicular to the mesoporous wood can provide rapid water transport via the pits and spirals. The cellulose nanofibers are circularly oriented around the pits and highly aligned along spirals to draw water across lumens. Meanwhile, the anisotropic thermal conduction of mesoporous wood is utilized, which can provide better insulation than widely used super‐thermal insulator Styrofoam (≈0.03 W m−1 K−1). The crossplane direction of wood exhibits a thermal conductivity of 0.11 W m−1 K−1. The anisotropic thermal conduction redirects the absorbed heat along the in‐plane direction while impeding the conductive heat loss to the water. The solar steam generation device is promising for cost‐effective and large‐scale application under ambient solar irradiance.

Multifunctional Solar Waterways: Plasma‐Enabled Self‐Cleaning Nanoarchitectures for Energy‐Efficient Desalination

“…The continuously increasing demands for economic development and increasing pollution lead to severe water scarcity in a growing portion of the world. [7][8][9][10][11][12][13][14][15] However, the state-of-the-art water desalination devices still suffer from several issues in energy efficiency, long-term performance, salt fouling, light blocking, and clean water collection in real-world applications. [3][4][5] A recent report combining solar harvesting and heat localization for evaporation achieved a relatively high energy efficiency over 85%, [6] opening up new opportunities for efficient solar desalination.…”

Superhydrophilic and Oleophobic Porous Architectures Based on Basalt Fibers as Oil‐Repellent Photothermal Materials for Solar Steam Generation

“…In recent years, several photothermal materials have been developed for solar steam generation, including natural products, carbon materials, gold nanoparticles, transition metal nitrides, hydrogels, porous polymers and clay‐based composites . These materials have characteristics such as superior light absorption, low thermal conductivity, and excellent porosity for rapid water transportation, which can enable impressive photothermal performance .…”

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 .…”