Scalable Carbon Black Enhanced Nanofiber Network Films for High‐Efficiency Solar Steam Generation

Abstract

Up to now, the manners for utilization of solar energy mainly focus on three aspects including photoelectric, [6][7][8] photochemical, [9][10][11] and photo thermal conversion. [12,13] Among them, the solar-thermal conversion based on direct transfer solar energy to heat is the most competitive technology for solar energy utilization and thus has become the subject of both academic research and industrial efforts. [14][15][16][17] Based on this, solar-driven steam generation shows many advantages in various fields such as seawater desalination, [18][19][20] sewage treatment, [21] and liquid-liquid separation [22,23] as well as sterilization and hygiene systems. [24] Most importantly, it can provide an ideal strategy to obtain a large amount of freshwater via seawater desalination. [25][26][27] The demand for freshwater is predicted to grow by more than 40% and two-thirds of the world's population will suffer from the lack of clean water by 2025. [28] Developing highly efficient seawater desalination is thus one of the most important technologies to address the great issue of increasingly global water resource scarcity. Traditionally, steam generation using solar energy is based on heating bulk liquid, which requires either special vacuum conditions or costly high optical concentrations. Many seawater desalination technologies such as reverse osmosis, [29] capacitive deionization, [30] and membrane distillation [31] have been reported. However, these technologies are based on the conventional route and generally rely on complicated optical concentrators for enhancing the water evaporation efficiency. In particular, during the seawater desalination process, the converted solar energy was partly used to heat bulk water or was lost to the external environment. [32,33] Therefore, it is inevitable that the efficiency of conventional solar desalination devices decreases dramatically with increasing bulk water quantity.In comparison, interfacial solar steam generation technology that localizes heating on a thin layer of water rather than the water bulk is a more competitive alternative to current solar steam generation technologies. To achieve high efficiency of solar steam generation, three main factors including efficient solar energy receiver, low heat loss, and sufficient fluid supply need to be taken into consideration. [26,34,35] Developing an efficient solar energy receiver is the most important as it directly determines the solar-thermal conversion efficiency. So far, various photothermal conversion materials with wide Developing cost-effective interfacial solar steam generation devices based on advanced structured materials for water desalination is highly desired. Herein, a high-efficiency solar steam generation based on a novel solar energy receiver of carbon black (CB)-based composite nanofiber networks with designed integrated 2D water path is reported. The receiver having a two-layer structure is prepared by a one-step electrospinning a suspension of CB particles in cellulose acetate (CA) onto a porous PET ...

A Review: Electrospinning Applied to Solar Interfacial Evaporator

“…Considering assembly of photothermal materials by electrospinning, the photothermal materials are embedded in polymer fiber matrices. [28,44,[53][54][55][56][57][58][59][60][61][62][63][64][65][66] The photothermal materials can be dispersed in the NFs, and the porous NF structure of the electrospun membrane enhances light absorption by creating multiple reflections within the pores, thus enhancing heat accumulation at the water-air interface. As a result, they can induce higher local temperatures and increase the efficiency of water evaporation.…”

“…Through the processing of electrospinning, granular amorphous carbon can be supported on certain substrates to achieve excellent properties. At present, CB has been encapsulated in nylon 6, [ 28 ] nylon 66, [ 57 ] cellulose acetate (CA), [ 58 ] and the porous carbon materials were prepared using Al‐based porous coordination polymers and assembled with polyurethane (PU) by electrospinning to form evaporators. [ 59 ] These composite membrane encapsulate the photothermal material in NFs rather than exposing them to the outside, resisting the loss of photothermal material and exhibiting good mechanical properties.…”

Towards highly salt-rejecting solar interfacial evaporation: Photothermal materials selection, structural designs, and energy management

“…Compared with the 3D structure of the natural biomass and foam materials, some 2D substrates with small-thickness are also able to play a superior performance, such as film and membrane [90][91][92][93][94][95][96][97]. As shown in Fig.…”

Mechanochemical synthesis and interfacial engineering of photothermal polymer composites for solar‐driven water evaporation

“…To evaporate water efficiently, photothermal materials with high light absorption, low heat conductivity, extremely high light-to-heat conversion, and adequate wettability have been explored. [18][19][20][21] Photothermal materials can be classified as follows: metals and metal oxides, [22][23][24][25] carbon-based materials, [26][27][28][29][30] inorganic semiconductors, 31,32 and polymers. [33][34][35] Although many of these materials exhibit adequate evaporation efficiency, achieving a material possessing all of the previously reported properties is still challenging.…”

“…To evaporate water efficiently, photothermal materials with high light absorption, low heat conductivity, extremely high light‐to‐heat conversion, and adequate wettability have been explored 18‐21 . Photothermal materials can be classified as follows: metals and metal oxides, 22‐25 carbon‐based materials, 26‐30 inorganic semiconductors, 31,32 and polymers 33‐35 .…”