A Low‐Cost 3D Spherical Evaporator with Unique Surface Topology and Inner Structure for Solar Water Evaporation‐Assisted Dye Wastewater Treatment

Abstract

Solar steam generation and adsorption, as promising technologies to tackle water pollution, have gained increasing research interest in recent years. In this paper, 3D spherical carbonized platanus fruit with special surface topology and inner interconnected porous structure is used as a superior solar evaporator and an adsorbent for dye removal with easy separation from treated water. The dual‐functional material with single component is prepared by a simply carbonizing biowaste platanus fruit. A high evaporation rate up to 2.00 kg m−2 h−1 under one sun is achieved by 3D spherical evaporator. 3D evaporator also presents outstanding water evaporation under low light intensity, angle‐independent water evaporation, and long‐term cycling stability. Importantly, high‐capacity dye adsorption and generation of purified water are simultaneously achieved with the assistance of solar‐driven evaporation under one sun. Thus, the monolithic, dual‐functional 3D material with a simple preparation process, low cost, mechanical robustness, and environmental friendliness has great potential for solar steam generation and solar water evaporation‐assisted adsorption. This study proposes a simple route to design 3D solar evaporators with surface topology and innovatively provides a high‐efficiency method for tackling water pollution.

Complete System to Generate Clean Water from a Contaminated Water Body by a Handmade Flower-like Light Absorber

“… 18 − 20 Especially, the fabrication of 3D geometric shapes with a rough exterior to increase exposed surface area, which ultimately leads to better solar light absorption and evaporation rates, such as 3D dyed black cotton towel, 3D hemispheric steam generator composed of nanocarbon, 3D spherical carbonized Platanus fruit, and so forth. 21 − 23 However, most of the designed solar light absorbers reported recently are still costly and composed of rare components with complex manufacturing processes. 24 Interfacial localized heating systems are needed in rural areas, so it is better to be simple and low-cost because the local economy, technical training, and resources of rural areas are limited.…”

Recent Progress on the Solar‐Driven Interfacial Evaporation Based on Natural Products and Synthetic Polymers

“…Zhao and coworkers [ 107 ] put the geopolymer slurry in a mold and coated it on the bottom surface of biomass mesoporous carbon (BMC) extracted from plant waste to prepare a SSGD that could realize efficient SSG on the base of the heat‐insulating PS foam. The evaporation rates of this device under 1 and 3 suns irradiation were 1.58 and 2.71 kg m −2 h −1 , respectively, and the photothermal conversion efficiencies were 85.0% and 67.6%, respectively.…”

Ultrablack Poly(vinyl alcohol)‐Graphite Composite Xerogel with Vertically Arranged Pores for Highly Efficient Solar Steam Generation and Desalination

“…The design of macroscopic three dimensional (3D) structures of the evaporators brings the solar steam generation performances of evaporators to a new level. These spatial structure designs, such as waved, [ 43 ] origami, [ 44,45 ] sunflower disc‐shaped, [ 46,47 ] cylindrical, [ 48,49 ] spherical, [ 16,50–52 ] cup‐like, [ 53 ] heatsink‐like, [ 54 ] and Monstera‐inspired, [ 35 ] significantly increase the solar steam generation performances through light and thermal managements. However, the following problems are worth paying attention to when designing evaporator.…”

“…The design of macroscopic three dimensional (3D) structures of the evaporators brings the solar steam generation performances of evaporators to a new level. These spatial structure designs, such as waved, [43] origami, [44,45] sunflower discshaped, [46,47] cylindrical, [48,49] spherical, [16,[50][51][52] cup-like, [53] heatsink-like, [54] and Monstera-inspired, [35] significantly increase the solar steam generation performances through light and thermal Ultrablack materials have attracted wide attention due to their high light absorbance and efficient photothermal conversion used in the field of solar steam generation to alleviate the drinking water crisis. Herein, ultrablack and low-cost poly(vinyl alcohol)-graphite composite xerogels (PGCXs) that have vertically arranged pores and high thermal conductivities are fabricated.…”