Graphene-Based Standalone Solar Energy Converter for Water Desalination and Purification

Abstract

Harvesting solar energy for desalination and sewage treatment has been considered as a promising solution to produce clean water. However, state-of-the-art technologies often require optical concentrators and complicated systems with multiple components, leading to poor efficiency and high cost. Here, we demonstrate an extremely simple and standalone solar energy converter consisting of only an as-prepared 3D cross-linked honeycomb graphene foam material without any other supporting components. This simple all-in-one material can act as an ideal solar thermal converter capable of capturing and converting sunlight into heat, which in turn can distill water from various water sources into steam and produce purified water under ambient conditions and low solar flux with very high efficiency. High specific water production rate of 2.6 kg h m g was achieved with near ∼87% under 1 sun intensity and >80% efficiency even under ambient sunlight (<1 sun). This scalable sheet-like material was used to obtain pure drinkable water from both seawater and sewage water under ambient conditions. Our results demonstrate a competent monolithic material platform providing a paradigm change in water purification by using a simple, point of use, reusable, and low-cost solar thermal water purification system for a variety of environmental conditions.

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

“…[6,[16][17][18][19][20] However, water is a thermally conductive material with high thermal conductivity of 0.599 W K −1 m −1 , much higher than the commonly used thermal-insulating materials (e.g., 0.117 W K −1 m −1 of carbon foam, [6] 0.069 W K −1 m −1 of bacteria nanocellulose, [16] and 0.016 W K −1 m −1 of graphene foam [19] ). [6,[16][17][18][19][20] However, water is a thermally conductive material with high thermal conductivity of 0.599 W K −1 m −1 , much higher than the commonly used thermal-insulating materials (e.g., 0.117 W K −1 m −1 of carbon foam, [6] 0.069 W K −1 m −1 of bacteria nanocellulose, [16] and 0.016 W K −1 m −1 of graphene foam [19] ).…”

Oxygen‐Defected Molybdenum Oxides Hierarchical Nanostructure Constructed by Atomic‐Level Thickness Nanosheets as an Efficient Absorber for Solar Steam Generation

“…However, this process usually suffers form high concentration sunlight because of the large energy losses, which hinders the large‐scale productions. To enhance the energy conversion efficiency, a method constructing floating porous photo‐thermal materials at the air‐water interface has attracted extensive attentions . Similar to natural plant transpiration and human sweating system, the heat generated by absorbers can be effectively localized at the interface and facilitate the vapor production.…”

“…Up to now, the commonly used materials in solar evaporation system include metallic plasmonic nanostructures, carbon‐based materials, and polymers . However, there are few investigates about applying transition metal oxides (TMOs) as solar receivers, which possess unique optical properties and widely used in photocatalysts, solar cells, photothermal conversions, photoelectrochemical (PEC) conversions, etc.…”

Solar‐Thermal Driven Self‐Heating of Micro‐Supercapacitors at Low Temperatures

“…Thus, we disregarded thermal convection in the energy flux (details and the corresponding explanation are shown in Figure S19, Supporting Information). The initial energy was obtained from sunlight, and solar energy can be converted into thermal energy by using a graphene photothermal film . Partial thermal energy converted from sunlight was lost through thermal radiation, and the bulk of this thermal energy was transferred into the gel electrolyte via thermal conduction.…”