Semiconductor nanoparticle-based hydrogels prepared via self-initiated polymerization under sunlight, even visible light

Abstract

Since ancient times, people have used photosynthesized wood, bamboo, and cotton as building and clothing materials. The advantages of photo polymerization include the mild and easy process. However, the direct use of available sunlight for the preparation of materials is still a challenge due to its rather dilute intensity. Here, we show that semiconductor nanoparticles can be used for initiating monomer polymerization under sunlight and for cross-linking to form nanocomposite hydrogels with the aid of clay nanosheets. Hydrogels are an emerging multifunctional platform because they can be easily prepared using solar energy, retain semiconductor nanoparticle properties after immobilization, exhibit excellent mechanical strength (maximum compressive strength of 4.153 MPa and tensile strength 1.535 MPa) and high elasticity (maximum elongation of 2784%), and enable recyclable photodegradation of pollutants. This work suggests that functional nanoparticles can be immobilized in hydrogels for their collective application after combining their mechanical and physiochemical properties.

Nanoparticle–Hydrogel Composites: Concept, Design, and Applications of These Promising, Multi‐Functional Materials

“…In a very recent study, Zhang et al synthesized semiconductor nanoparticle‐based hydrogels by self‐initiated polymerization under light irradiation 27. The system consisted of four components: i) water, ii) water soluble semiconductor nanoparticles of zinc oxide (ZnO), titanium dioxide (TiO 2 ), iron(III) oxide (Fe 2 O 3 ), tin dioxide (SnO 2 ), zirconium dioxide (ZrO 2 ), cadmium selenide (CdSe) or cadmium telluride (CdTe), iii) N , N ‐dimethylacrylamide (DMAA), and iv) clay nanosheets.…”

Photodegradation of methylene blue with a titanium dioxide/polyacrylamide photocatalyst under sunlight

“…Characterization IR spectroscopy was carried out on a Bruker Vector 22 Fourier transform infrared (FTIR) spectrometer (Germany) in the region 4000-500 cm 21 . The samples were prepared in the form of pellets with KBr under ambient conditions and were measured in transmission mode.…”

“…Preparation of the PAAm Hydrogel with a TiO 2 P25 Initiator (TiO 2 /PAAm) An amount of 0.3 g of AAm was dissolved in 6 mL 21 of distilled water in a 50-mL round-bottomed balloon. Then, 0.0037 g of MBA (MBA/AAm 5 1:80) 27 was added to the monomer solution under stirring.…”

“…21 Photoinitiators, such as TiO 2 , CdTe, and ZnO NPs, have been applied to the polymerization of vinyl monomers. 22 There have been several reports in which semiconductors were applied to the polymerization of vinyl monomers under UV light.…”

“…22 There have been several reports in which semiconductors were applied to the polymerization of vinyl monomers under UV light. [23][24][25] Zhang et al 21 reported the polymerization of N,Ndimethyl acrylamide using semiconductor NPs as the initiator under sunlight. Also, Bao et al 26 carried out the polymerization of N,N-dimethyl acrylamide and 2-acrylamide-2-methyl propane sulfonic acid monomers with a 2,2-diethoxyacetophenone photoinitiator.…”