Thermally driven characteristic and highly photocatalytic activity based onN-isopropyl acrylamide/high-substituted hydroxypropyl cellulose/g-C3N4hydrogel by electron beam pre-radiation method

A new type ofN-isopropyl acrylamide/high-substituted hydroxypropyl cellulose/graphite carbon nitride (NIPAAm/HHPC/g-C3N4) smart hydrogel-based photocatalyst with thermally driven characteristic was successfully prepared by electron beam pre-radiation polymerization and radiation cross-linking methods. The agglomeration and loss of g-C(3)N(4)nanosheets can be avoided effectively, and ensured high photocatalytic activity under visible light, once the g-C(3)N(4)nanosheets are uniformly dispersed into the skeleton of a thermosensitive NIPAAm/HHPC hydrogel. NIPAAm/HHPC/g-C3N4(NHC) hydrogel was characterized by nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The microstructure of NHC was further characterized by scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller. The adsorption-photocatalytic removal rate of rhodamine B reached 71.4% at the mass ratio of g-C(3)N(4)of 0.8% (NHC-0.8%) hydrogel in an aqueous medium under visible light. The thermal shrinkage ratio can reach 90.6% at 60 degrees C after 5 min and could effectively achieve the function of recycling-free in a portable photocatalytic reaction device under the optimal conditions. Possible mechanism of adsorption-photocatalysis and thermally driven recycling-free on NHC hydrogel was also obtained. These thermally driven recycling-free characteristic and highly photocatalytic properties of the hybrid hydrogel-based photocatalyst show that it can be used as a promising new material with extensive applications in wastewater treatment.