Zinc oxide-filled polyvinyl alcohol–cellulose nanofibril aerogel nanocomposites for catalytic decomposition of an organic dye in aqueous solution

Abstract

This paper discusses the preparation of polyvinyl alcohol/cellulose nanofibril (PVA–CNF) aerogel nanocomposites loaded with zinc oxide (ZnO) particles via the freeze-thaw process, followed by subsequent in-situ synthesis of ZnO particles using zinc chloride and ammonium solution. Aerogel samples were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and Brunauer–Emmet–Teller analysis. The aerogels were used for decoloration of methylene blue (MB) in aqueous solution via simultaneous adsorption and catalytic degradation with sodium borohydride. The adsorption behavior of MB on the aerogel was investigated with the aid of kinetics and isotherm models and found to fit a Langmuir model, which suggested monolayer adsorption of dye with maximum adsorption capacity of 24.53 mg/g. The presence of ZnO particles in the stable and reusable crosslinked PVA–CNF aerogel has improved the removal of MB as high as two folds after ten cycles of treatment.