Bioinspired Bifunctional Membrane for Efficient Clean Water Generation

Abstract

Solving the problems of water pollution and water shortage is an urgent need for the sustainable development of modern society. Different approaches, including distillation, filtration, and photocatalytic degradation, have been developed for the purification of contaminated water and the generation of clean water. In this study, we explored a new approach that uses solar light for both water purification and clean water generation. A bifunctional membrane consisting of a top layer of TiO2 nanoparticles (NPs), a middle layer of Au NPs, and a bottom layer of anodized aluminum oxide (AAO) was designed and fabricated through multiple filtration processes. Such a design enables both TiO2 NP-based photocatalytic function and Au NP-based solar-driven plasmonic evaporation. With the integration of these two functions into a single membrane, both the purification of contaminated water through photocatalytic degradation and the generation of clean water through evaporation were demonstrated using simulated solar illumination. Such a demonstration should also help open up a new strategy for maximizing solar energy conversion and utilization.

Extremely Cost‐Effective and Efficient Solar Vapor Generation under Nonconcentrated Illumination Using Thermally Isolated Black Paper

“…This is also applicable to other reported solar vapor generation systems (e.g., ref. ) since they are also covered by a film of water and/or surrounded by heated vapor. However, this physical mechanism was not detailed in previous reports.…”

Morphology Control of Ag Polyhedron Nanoparticles for Cost‐Effective and Fast Solar Steam Generation

“…Most of the previous reports have mainly focused on the roles of the absorption spectrum for solar thermal conversion, and obtained the harvesting solar energy performances through artificial light simulator or laser in the laboratory . The practical running performances and dominant factors of harvesting solar energy for steam generation under the actual sunlight are rarely reported.…”

Fast‐Growing Field of Interfacial Solar Steam Generation: Evolutional Materials, Engineered Architectures, and Synergistic Applications

“…By integrating these two functions into a integrative device, both the contaminated water is purified by photocatalytic degradation and the clean water is produced by evaporation were showed under the simulate sun radiation. The as‐designed bifunctional membrane can achieve a solar energy utilization greater than that of single‐function film . The combination of TiO 2 nanoparticles as the photocatalytic material and Au nanoparticles as the seawater desalination plasmonic material is particularly instructive for follow‐up researches.…”

“…TiO 2 and high‐energy photons in the visible to near infrared region can interact to form electron‐hole pairs upon exposure to sunlight; and SiO 2 /Ag and low‐energy photon can interact to generate heat thereupon. As a result, the ISSG device made of the core‐shell nanocomposite can be used to simultaneously desalinate seawater and produce energy . The as‐fabricated core‐shell structure ISSG device consists of parabolic grooves that focus light to the bottom of the quartz tube for transmitting light, adiabatic grooves for reducing heat loss, thermocouples for measuring temperature changes, and a water vapor filter for separating hydrogen and steam.…”

“…a) Schematic diagram of the combinatory ISSG device used for both photocatalytic and desalination (the three‐layer structure from top to bottom: TiO 2 naoparticle (NP) layer, Au NP layer, and an anodized aluminum oxide layer). Reproduced with permission . Copyright 2015, American Chemical Society.…”