Effective photocatalytic degradation of Congo red dye using alginate/carboxymethyl cellulose/TiO2 nanocomposite hydrogel under direct sunlight irradiation

Abstract

Nanocomposite hydrogels of barium ion crosslinked alginate/carboxymethyl cellulose (CMC) with encapulation of TiO2-NPs were synthesized sucessfully using dissipative convective method followed by freeze-drying procedure. As-prepared composite hydrogels were charecterized by different techniques such as Fourier Transform Infrared spectroscopy (FT-IR), Powder X-ray diffraction (PXRD), UV- Diffuse reflectance spectroscopy (UV-DRS), BET-Surface area study, Scanning Electron Microscopy with Energy Dispersive X-ray analysis (SEM-EDAX), Transmission Electron Microscopy (TEM) and mechanical strength study. Ba/Alg/CMC/TiO2 composite hydrogels exhibited excellent photocatalytic activity towards CR under direct solar light irradiation with pseudo-first order kinetics. The recycling ability of Ba/Alg/CMC/TiO2 composite hydrogels confirms that photocatalyst is highly photostable.