A 3D porous PDMS sponge embedded with carbon nanoparticles for solar driven interfacial evaporation

Integrating solar evaporation-driven desalination and electricity production has emerged as a promising approach to alleviate energy crisis and freshwater scarcity. However, there remain huge challenges to achieve high water productivity and steady power generation efficiency. Herein, a compact evaporation-induced water–electricity co-generation device was proposed using a bio-waste squid ink sphere-based cellulose fabric as an evaporator and a silicon nanowires array-based evaporation-driven moist-electric generator. The efficient localized solar thermal heating of the photothermal component leads to significant enhancement in freshwater yield, and the latent heat of vapor condensation is recycled to promote the electricity generation. More notably, the device is capable of harvesting wind energy toward all-weather water and power generation. The fabricated device demonstrated a high evaporation rate of 2.17 kg m–2 h–1 with a collection rate of 66.7% and a maximum output voltage of 1.48 V under one sun illumination with a wind speed of 4 m s–1. The outdoor experiments display a maximum water evaporation rate of 1.84 kg m–2 h–1 with a maximum output voltage of 1.35 V even on cloudy days. Such superior performance of a comprehensive device has great potential for sustainable and practical application in freshwater and electricity generation.

Section: Resultsmentioning

confidence: 99%

All-Weather Freshwater and Electricity Simultaneous Generation by Coupled Solar Energy and Convection

Fang

Liu

Chen

et al. 2022

“…However, these industrial techniques require large amounts of fossil fuel energy and large-scale investments in infrastructure, limiting their large-scale and portable application . In response to these restrictions, scientists have developed solar-driven interfacial evaporators and devices to achieve green, sustainable, and portable , techniques for seawater desalination and sewage treatment over the past decade. − A wide range of materials had been used to create efficient interfacial evaporators, including natural wood, , porous plants, membranes, , sponges, , synthetic hydrogels, , and aerogels. , However, there are some intrinsic limitations to these evaporators, such as a high preparation cost, complex synthesis process, or limited portability, , which cannot meet the requirements of low cost, large-scale production, and eco-friendliness. , …”

Section: Introductionmentioning

confidence: 99%

Rapid Fabrication of Porous Photothermal Hydrogel Coating for Efficient Solar-Driven Water Purification

Peng

et al. 2022

Cost management and scalable fabrication without sacrificing the purification performance are two critical issues that should be addressed before the practical commercial application of solar-driven evaporators. To address this challenge, we report a porous photothermal hydrogel coating prepared by mixing the raw materials of sawdust (SD), carbon nanotubes (CNTs), and poly(vinyl alcohol) (PVA), which was applied to undergo a blading–drying–rehydration process to prepare the evaporator. In the coating, the crystallized PVA gives the coating a solid skeleton and the sawdust endows the coating with a loose structure to sufficiently enhance the water transportation capacity. As a result, the evaporator coated with the hydrogel coating displays a high water transport rate and efficient evaporation performance along with excellent mechanical properties and stability. Water migrates vertically upward 5 cm within 4 minutes. The compressive stress of the rehydrated hydrogel coating reaches as high as 14.28 MPa under 80% strain. The water evaporation rate of the hydrogel coating-based evaporator reaches 1.833 kg m–2 h–1 corresponding to an energy efficiency of 83.29% under 1 sun irradiation. What is more, the hydrogel coating retains its excellent evaporation performance and stability after immersion in acid or alkali solution, ultrasound treatment, and long-time immersion in water. Under outdoor conditions, the water evaporation rate of the hydrogel coating-based evaporator is about 5.69 times higher than that of pure water. This study proposes a rapid, cost-effective, and scalable strategy for preparing a high-performance photothermal hydrogel coating that will find sustainable and practical application in solar-driven water purification.

“…25,29 To mitigate the heat loss and enhance the evaporation rate, a double-layer interface evaporator combining photothermal membranes with a thermal insulator layer was developed to restrict heat conduction from the photothermal membrane to water. 10,30 However, it should be worth noting that the fast evaporation rate may lead to inadequate saline ion diffusion rates, while salt crystal blockage can significantly hinder the absorption of light, thereby reducing evaporation rates and finally causing irreversible damage to the evaporator. 33−37 Therefore, preventing salt accumulation is a major challenge in the development of an efficient solar-driven evaporator.…”

Section: Introductionmentioning

confidence: 99%

“…Previously, many photothermal materials have been developed, such as metal materials, − carbon materials, − polymeric materials, and semiconductor materials . These photothermal particles were directly dispersed in an aqueous solution for solar-driven evaporation.…”

Section: Introductionmentioning

confidence: 99%

“…These photothermal particles were directly dispersed in an aqueous solution for solar-driven evaporation. However, this system would cause huge heat loss, leading to a low evaporation rate. , To mitigate the heat loss and enhance the evaporation rate, a double-layer interface evaporator combining photothermal membranes with a thermal insulator layer was developed to restrict heat conduction from the photothermal membrane to water. , However, it should be worth noting that the fast evaporation rate may lead to inadequate saline ion diffusion rates, while salt crystal blockage can significantly hinder the absorption of light, thereby reducing evaporation rates and finally causing irreversible damage to the evaporator. − Therefore, preventing salt accumulation is a major challenge in the development of an efficient solar-driven evaporator. To date, there are various solutions to solve the salt blocking issue, such as intermittent operations, localized salt crystallization, washing, mechanical removal, and Marangoni effect salt rejection …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Janus Carbon Nanotube@poly(butylene adipate-co-terephthalate) Fabric for Stable and Efficient Solar-Driven Interfacial Evaporation

Zhao

Chen

et al. 2022

Solar-driven seawater desalination is considered a promising method for alleviating the water crisis worldwide. In recent years, significant efforts have been undertaken to optimize heat management and minimize salt blockage during solar-driven seawater desalination. However, it remains challenging to achieve an efficient and stable seawater evaporator simply and practically. Here, we designed and prepared a novel three-dimensional (3D) water channel evaporator (3D WCE) equipped with a Janus CNT@PBAT fabric (JCPF). The as-prepared Janus CNT@PBAT fabric has broad-band light absorption (∼97.8%), excellent superhydrophobicity (∼162°), and photothermal properties. After optimizing the structure of the thermal insulator, our designed evaporator could realize the equilibrium between enhanced thermal management and sufficient water supply. As a result, the as-prepared evaporator achieved an excellent evaporation rate of 1.576 kg•m −2 •h −1 and an energy efficiency of over 92.7% under 1 sun irradiation in 3.5 wt % saline water. Moreover, this evaporator also revealed good salt rejection performance compared to the traditional two-dimensional (2D) water channel evaporator (2D WCE) in high saline water, which could maintain stable evaporation rates under long-term evaporation of 8 h. Our study may develop a simple method for the design and fabrication of a low-cost, effective, and stable solar-driven evaporator for seawater desalination.