Composite Polyelectrolyte Photothermal Hydrogel with Anti-biofouling and Antibacterial Properties for the Real-World Application of Solar Steam Generation

Abstract

Solar steam generation provides a promising and low-cost solution for freshwater production in energy scarcity areas. However, in real-world applications, evaporators are easily affected by microorganism contamination in source water, causing surface corrosion, structural damage, or even invalidation. Developing anti-biofouling and antibacterial evaporators is significant for long-term stable freshwater production. Herein, a composite polyelectrolyte photothermal hydrogel consisting of sulfobetaine methacrylate (SBMA), [2-(methacryloyloxy)­ethyl]­trimethylammonium chloride (METAC), and polypyrrole (PPy) with anti-biofouling and antibacterial properties is developed. Crediting sufficient ammonium groups and zwitterionic segments, the optimized polyelectrolyte hydrogel exhibits an ∼90% antibacterial ratio against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and effectively controls biological contamination. Under 1.0 kW m–2 solar irradiation, a rapid water evaporation rate of ∼1.690 kg m–2 h–1 and a high solar-to-evaporation efficiency of ∼95.94% are achieved with the photothermal hydrogel. We show that a lab-made setup integrated with the hydrogel can realize ∼0.455 kg m–2 h–1 freshwater production from seawater under natural sunlight. Moreover, the hydrogel exhibits excellent durability with a stable evaporation rate of ∼1.617 kg m–2 h–1 in real seawater for over 6 weeks, making it fullhearted in the real-world application of solar steam generation.

Highly Effective Multifunctional Solar Evaporator with Scaffolding Structured Carbonized Wood and Biohydrogel

“…Solar evaporators have attracted much attention as an efficient technology for desalination and power generation. 1,2 A solar evaporator absorbs solar energy to generate heat at the water−air interface and converts water into steam to obtain clean water and energy. 3,4 The evaporation performance relies on the framework structure of evaporators, which usually have the following characteristics: 5,6 first, appropriate materials and structure are necessary for high solar energy absorption and photothermal conversion efficiency.…”

“…Water and energy shortages are the two major challenges in some developing countries. Solar evaporators have attracted much attention as an efficient technology for desalination and power generation. , A solar evaporator absorbs solar energy to generate heat at the water–air interface and converts water into steam to obtain clean water and energy. , The evaporation performance relies on the framework structure of evaporators, which usually have the following characteristics: , first, appropriate materials and structure are necessary for high solar energy absorption and photothermal conversion efficiency. , Second, the evaporator structure needs to be efficient for water transportation and robust to avoid channel clogging by salt crystallization . Third, the contact interface between the structure and water needs to be meticulously designed to achieve a high efficiency and versatility, which includes reducing vaporization enthalpy, regulating surface energy and temperature distribution, and realizing hydrovoltaic power generation. − …”

Sustainable Self-Cleaning Evaporators for Highly Efficient Solar Desalination Using a Highly Elastic Sponge-like Hydrogel

“…To further verify that the ion concentration was effectively reduced after Bohai Sea seawater purification, the concentrations of four main metal ions (Na + , K + , Ca 2+ , and Mg 2+ ) were detected before and after seawater purification (Figure b). We found that the metal ion concentrations were significantly reduced and met the World Health Organization (WHO) drinking water standards . The above results showed that the salt ion content in the seawater significantly decreased after it was purified by the CVM4 evaporator.…”

“…We found that the metal ion concentrations were significantly reduced and met the World Health Organization (WHO) drinking water standards. 48 The above results showed that the salt ion content in the seawater significantly decreased after it was purified by the CVM4 evaporator. Subsequently, wastewater purification experiments were carried out by treating simulated organic dye wastewater (MB and MO solutions with certain concentrations).…”

Recent advances in structural regulation and optimization of high-performance solar-driven interfacial evaporation systems

“…This composite polyelectrolyte photothermal hydrogel maintained stable evaporation for more than six weeks in real seawater. 193…”