Broadband solar‐driven water evaporator based on organic hybrid bandgap and bio‐mimetic interfaces

Abstract

Owing to the lightweight, flexibility, and molecular diversity, organic photothermal materials are considered promising solar absorbent materials for water-evaporating purification. Herein, we utilize the blend of two organic conjugated photothermal materials, PM6 and Y6, with broadband solar absorption from 350 to 1000 nm and high-efficiency photothermal properties to fabricate a Janus water evaporator on cellulose paper. Similar to the asymmetric wetting behavior on the lotus leaf, the evaporator shows efficient water adhesion on the bottom surface and water repellency on the top surface for a desirable self-floating capability and salt resistance. With a mass of only 0.5 mg per 3.14 cm 2 , the PM6:Y6 blend-based water evaporator achieves 88.9% of solar thermal conversion efficiency (η) and 1.52 kg m À2 h À1 of solar water evaporation rate (m) under 1.0 kW m À2 solar irradiation. These properties are almost the best performance among purely

PDI‐Based Organic Small Molecule Regulated by Inter/Intramolecular Interactions for Efficient Solar Vapor Generation

“…The PDI core with planar and rigid multi-ring 𝜋electron conjugation system causes PDI-DTMA molecule to aggregate through intermolecular 𝜋-𝜋 interaction, favorable for broadening the absorption spectrum and strengthening the photothermal conversion. [9,12,15,16,18] Additionally, the electrondonating 3,4,5-trimethoxyphenyl moieties are strategically attached to the imide positions of the electron-accepting PDI core, resulting in the D-A-D configuration of PDI-DTMA. [27,28] The modification of the electron donor to the acceptor can reduce the band gap, so as to achieve the optimization of light absorption and photothermal conversion.…”

“…Strategies, such as regulation of molecular stacking, enhancement of intramolecular charge transfer, introducing intramolecular motion and free radicals, have been employed to narrow the band gap, thereby maximizing photothermal conversion efficiency. [10][11][12][13][14][15][16][17][18][19] Despite these efforts, the number of available organic small molecules for solar water evaporation remains limited. Additionally, most of these evaporators lack subtle design, resulting in unsatisfactory water evaporation rates (<1.55 kg m −2 h −1 under 1 kW m −2 ), which are lower than recently reported evaporation rates.…”

Sweat Gland-Inspired Skin-like Fabric with Directional Water Transport and Durability for Efficient Personal Moisture Management

“…Recently, comfortable functional textiles have received massive attention for work- and sportswear applications because of their critical role in the performance of the wearer. − The comfort feature of such textiles is regulated by their moisture transport ability . It is well established that perspiration plays a critical role in the human body’s water and thermal regulation .…”

“…1−3 The comfort feature of such textiles is regulated by their moisture transport ability. 4 It is well established that perspiration plays a critical role in the human body's water and thermal regulation. 5 Inadequate moisture transport may cause wearer discomfort and even induce heat-related sickness, particularly in tropical environments.…”

Biomimetic Seawater Evaporator Based on Organic 3D Light Capture and Suspension‐Protection Mechanism for In Situ Marine Cultivation

“…[41][42][43][44] When used in solar desalination, Y6 showed a solar-energy-to-vapor conversion efficiency (𝜂) of 64.4% and solar water evaporation rate ( ṁ) of 1.13 kg m −2 h −1 under one sun irradiation. [45] This class of small molecules leverages the push-pull electron effect between an electron-donating unit (D) and electron-withdrawing unit (A) to broaden and enhance light absorption. In terms of photothermal conversion, a strategy to boost the electron-withdrawing ability of the A units in conjugated molecules is expected to further improve light absorption and conversion efficiency, a subject that has scarcely been reported.…”