Photothermal Membrane of CuS/Polyacrylamide–Carboxymethyl Cellulose for Solar Evaporation

Abstract

Solar water evaporation is an environment-friendly and clean way of wastewater treatment and seawater desalination. However, a solar evaporator based on a hydrogel substrate still needs excellent toughness to ensure continuous and stable utilization while achieving a fast evaporation rate. In this research, a solar evaporator based on a dual network hydrogel was fabricated by double chemical cross-linking, consisting of polyacrylamide (PAAm), carboxymethyl cellulose (CMC), and CuS. By utilizing N,N′methylenebisacrylamide (MBA) and Fe 3+ for a double chemical cross-linking agent, PAAm and CMC (PAAm−CMC) formed an interpenetrating dual network structure, which is helpful to improve the mechanical properties of a photothermal membrane. The breaking elongation of a CuS/PAAm−CMC membrane is 480%. Meanwhile, the hydrophilic network ensured the high efficiency of water transmission and water activation. The evaporation rate reached 1.613 kg m −2 h −1 at 1 sun, and the photothermal conversion efficiency reached 79%. In the process of a simulated desalination experiment (10 wt % NaCl solution), the evaporation rate did not decrease after 10 cycles, indicating the self-cleaning ability and good durability of CuS/PAAm−CMC.

Recent developments of hydrogel based solar water purification technology

“…33 Commonly, LSPR spectral band can be expanded by hollow structure, asymmetrical design, particlesize shifts, and dielectric surroundings 72 to compensate for the inherent shortcoming of the narrow absorption spectra of plasmonic nanoparticles caused by their specific geometrics. 39 Common plasmonic nanoparticles used as solar absorbers include Ag, [73][74][75][76] Au, 77 CuS, [78][79][80][81] Cu, 44,82 and so on. Recently, Wang et al 26 reported a novel plasmonic Cu7S4-MoS2-Au composite nanoparticle (CMA NP) with broad absorption and high photothermal conversion efficiency, which arises from the coupling effect among Cu7S4, MoS2 and Au, as well as the comprehensive utilization of their advantages(Figures 3a and 3b).…”

“…Common plasmonic nanoparticles used as solar absorbers include Ag, 73–76 Au, 77 CuS, 78–81 Cu, 44,82 and so on. Recently, Wang et al 26 reported novel plasmonic Cu 7 S 4 –MoS 2 –Au composite nanoparticles (CMA NPs) with broad absorption and high photothermal conversion efficiency, which arises from the coupling effect among Cu 7 S 4 , MoS 2 and Au, as well as the comprehensive utilization of their advantages (Fig.…”

A 3D Opened Hollow Photothermal Evaporator for Highly Efficient Solar Steam Generation

“…Herein, a 3D opened hollow cylinder-like solar evaporator (OHCE) was constructed using hierarchically porous CuS-cellulose composite (CSC) as light absorber. Although various CuS nanostructures have been prepared and utilized as photothermal materials for solar evaporation, [44][45][46][47][48] porous structured CuS has not been explored for fabricating 3D photothermal evaporators. The CSC-coated sheet (Figure S1, Supporting Information) was tailored and wrapped on a steel frame to fabricate an OHCE with four slots on its side evaporation surfaces (Figure 1).…”

A Simple Polypyrrole/Polyvinylidene Fluoride Membrane with Hydrophobic and Self-Floating Ability for Solar Water Evaporation

“…Solar vapor generation (SVG) is one of the most important ways to utilize solar energy [ 1 , 2 , 3 , 4 , 5 ]. In recent years, SVG has attracted much attention due to the increasing demand of fresh water [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. The introduction of interface SVG, which is a self-floating solar absorber to float at the water–air interface, further improves the photothermal conversion efficiency of solar energy [ 13 , 14 , 15 ].…”