Low Cost, Robust, Environmentally Friendly Geopolymer–Mesoporous Carbon Composites for Efficient Solar Powered Steam Generation

Abstract

High-efficiency, environment friendly, renewable energy-based methods of desalination represent attractive and potentially very powerful solutions to the long-standing problem of global water shortage. Many new laboratoryscale materials have been developed for photothermal desalination but the development of low-cost, easy-to-manufacture, and scalable materials and systems that can convert solar irradiation into exploitable thermal energy in this context is still a significant challenge. This paper presents work on a geopolymer-biomass mesoporous carbon composite (GBMCC) device with mesoporous and macroporous structures for harvesting solar energy, which is then used in a device to generate water vapor with high efficiency using negative pressure, wind-driven, steam generation. The GBMCC device gives water evaporation rates of 1.58 and 2.71 kg m −2 h −1 under 1 and 3 suns illumination, with the solar thermal conversion efficiency up to 84.95% and 67.6%, respectively. A remarkable, record high water vapor generation rate of 7.55 kg m −2 h −1 is achieved under 1 sun solar intensity at the wind speed of 3 m s −1 . This is a key step forward todays efficient, sustainable and economical production of clean water from seawater or common wastewater with free solar energy.

Multifunctional Solar Waterways: Plasma‐Enabled Self‐Cleaning Nanoarchitectures for Energy‐Efficient Desalination

“…The continuously increasing demands for economic development and increasing pollution lead to severe water scarcity in a growing portion of the world. [7][8][9][10][11][12][13][14][15] However, the state-of-the-art water desalination devices still suffer from several issues in energy efficiency, long-term performance, salt fouling, light blocking, and clean water collection in real-world applications. [3][4][5] A recent report combining solar harvesting and heat localization for evaporation achieved a relatively high energy efficiency over 85%, [6] opening up new opportunities for efficient solar desalination.…”

Portable Low‐Pressure Solar Steaming‐Collection Unisystem with Polypyrrole Origamis

“…As shown in Figure S3 (Supporting Information), we can readily fabricate a PPy origami with a diameter as large as 22 cm at lab conditions. The estimated cost of PPy paper is $18 m −2 (Table S2, Supporting Information), which is among the lowest cost of the reported materials, around half of that of geopolymer–mesoporous carbon composites . Further characterizations including scanning electron microscopy (SEM) imaging (Figure c,d), Raman spectroscopy (Figure S4a, Supporting Information), and energy‐dispersive X‐ray spectroscopy (EDS) (Figure S4b, Supporting Information) confirm the chemistry and successful coating of PPy onto cellulose paper (Note S1, Supporting Information).…”

“…Over the past 5 years, a number of photothermal materials with designed chemistry and structures have been investigated for high‐efficiency solar steaming . The studied materials range from plasmonic metal nanoparticles (NPs) to carbonaceous materials . Some reported materials exhibit excellent performances; however, many of them suffer limitations due to the utilization cost of noble metals, or the integration of complex or fragile nanostructures .…”

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materials. [18][19][20][21][22][23] Some reported materials exhibit excellent performances; however, many of them suffer limitations due to the utilization cost of noble metals, or the integration of complex or fragile nanostructures. [3,4,6,7,16,17,24] For some materials, the fabrication involved e-beam deposition, [3,16] synthesis and reduction of graphene oxide (GO), [18,21] chemical vapor deposition of graphene foams, [24] and freeze-drying for aerogels, [21,22] which can be time consuming and costly for manufacturing.

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Graphene–Carbon Composites for Solar and Low‐Voltage Powered Efficient Interfacial Evaporation

“…[11] Therefore, devices solely powered by solar energy are not suitable for practical and industrial applications that require high-speed evaporations such as distillations, purification, sterilization, and so on. [12] The cost of using optical devices to enhance the illumination intensity will be significantly high, while Joule heating (or thermal effect of current, the most fundamental and useful property of electricity), is inexpensive, robust and promising for sustainable energy utilizations.Flexible heaters have also been one of the hotspots of the research on functional materials in recent years due to their high heating efficiency, light weight, and superior mechanical properties. They have been used for wearable electronics, hot plates, electric blankets, smart windows, and so on.…”