Low-Tortuosity Water Microchannels Boosting Energy Utilization for High Water Flux Solar Distillation

Abstract

Solar distillation through photothermal evaporators has approached solar light energy (E1) limit under no solar concentration but still suffers from modest vapor and clean water production. Herein, a nature-inspired low-tortuosity three-dimensional (3D) evaporator is demonstrated to significantly improve water production. The solar evaporator, prepared from polypyrrole-modified maize straw (PMS), had upright vascular structures enabling high water lifting and horizontal microgaps facilitating broad water distribution to the out-surface. Consequently, this novel PMS evaporator dramatically enhanced the utilization of the solar heat energy stored in the environment (E2) for promoting evaporation. The maximum vapor generation rate of a single PMS respectively increases 2.5 and 6 times compared with the conventional 3D evaporators and the planar evaporators of an identical occupied area. Consequently, a scaled-up PMS array achieved a state-of-the-art vapor generation rate of 3.0 L m–2 h–1 (LMH) under a simulated condition and a record-high clean water production of 2.2 LMH for actual seawater desalination under natural conditions (1 sun intensity). This breakthrough reveals great potentials for cost-effective freshwater production as well as the rational design of high-performance photothermal evaporators for solar distillation.

Marriage of 2D Covalent–Organic Framework and 3D Network as Stable Solar‐Thermal Still for Efficient Solar Steam Generation

“…[ 3 ] Among these methods, solar thermal water evaporation is one of the most promising techniques by harvesting clean and abundant solar energy to produce clean water. [ 4–8,44–47 ] In the past few years, clean water generation via solar evaporation technology has been reported by using solar absorbers based on various photothermal conversion materials, like plasmatic metals, carbon‐based materials, semiconductor materials, polymers, and hybrid composites. [ 9–15 ] It is known that efficient solar evaporation strongly depends on the absorbers, which can absorb light and transfer solar energy to heat for water evaporation.…”

Perspective for removing volatile organic compounds during solar‐driven water evaporation toward water production

“…Developing a low‐cost solar‐powered device, such as solar evaporation system, to produce fresh water from saline, could be an ideal solution for both water and energy supply. Great effort has been made in many aspects, such as developing new materials with higher light‐to‐heat conversion efficiency, 2 designing water channel, 3 optimizing system salt crystallization resistance, 4,5 carrying out system thermal management to achieve higher light‐to‐vapor efficiency, 6,7 using solar photothermal water purification technology to decontaminate industrial wastewater, 8 investigating the evaporation‐driven electricity generation, and so forth 9–11 . Nowadays, photothermal evaporation system is developing toward higher water yield and higher efficiency in the continuous optimization process.…”

In Situ Fenton Triggered PDA Coating Copper Mesh with Underwater Superoleophobic Property for Oily Wastewater Pretreatment

“…The invention of superwetting surfaces opens up new insights and routes for the key part of oily sewage pretreatment: oil/water mixture separation [7,8]. Different from the energy-consuming process of traditional technology, super-wetting material can separate oil and water through interfacial action under the condition of only using gravity; hence, the Processes 2021, 9, 1665 2 of 9 operating cost is much lower [9,10]. As a typical example, inspired by the phenomenon that fish can keep their surfaces clean in oil-polluted water, Jiang and co-workers first developed an alternative method of preparing an underwater superoleophobic interface in an aqueous medium [11].…”