Composite Polyelectrolyte Photothermal Hydrogel with Anti-biofouling and Antibacterial Properties for the Real-World Application of Solar Steam Generation
Bolun Peng, Quanqian Lyu, Yujie Gao, Miaomiao Li, Ge Xie, Zhanjun Xie, Hanchao Zhang, Jingli Ren, Jintao Zhu, Lianbin Zhang, Peng Wang
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.