Fabrication of antibacterial and biomimetic chitosan-based hydrogel
embedded with Ag/MXene nanocomposites as photothermal centers for solar
steam generation and desalination
Abstract
Solar-driven interfacial steam generation is considered as a sustainable
and cost-effective approach to produce freshwater from seawater or
sewage, whereas unavoidable microbial contamination and low evaporation
efficiency remain challenges. Herein, we report a high-performance and
antibacterial 3D Ag/MXene@chitosan hydrogel (described as AM/Ch gel)
evaporator through incorporation of two-dimensional (2D) Ag/MXene
composites into three-dimensional (3D) chitosan hydrogel. Thanks to the
synergistic contributions from chitosan hydrogel matrix and Ag/MXene
composites, 3D AM/Ch gel could completely eradicate both E. coli and S.
aureus under simulated solar light irradiation, ensuring the production
of microbial-free drinkable water. Benefiting from the superb
photo-to-thermal conversion behavior and feasible water transportation
in the 3D networks, the prepared AM/Ch gel-based evaporator exhibits
intriguing solar steam generation performances, with evaporation rate
and solar energy utilization efficiency of 3.22 kg m–2 h–1 and 94.9%
under irradiation of 0.2 W cm–2, respectively. As a demonstration, the
quality of collected liquid water evaporated from seawater adopted from
the Yellow Sea, China, well satisfies the requirement for drinking water
from World Health Organization. Moreover, the AM/Ch gel exhibits high
flexibility and chemical stability, excellent dye molecules adsorption
capacity and self-cleaning ability, indicating its promising potential
for durable and sustainable water distillation.