Synergetic photocatalytic and adsorptive removals of metanil yellow using TiO2/grass-derived cellulose/chitosan film composite

Abstract

Chitosan (CH) and cellulose are the most abundant biopolymers which could be utilized for hazardous dye removal. By incorporating TiO2 onto cellulose/CH matrix, our research aimed to achieve high metanil yellow removal by means of synergetic adsorption/photodegradation mechanism. The cellulose particles were extracted from wild grass (Imperata cylindrica L.) to obtain grass-derived cellulose (GC). Simple blending method was used to prepare TiO2/GC/CH, in which the composition was determined by simple additive weighting method (SAW). TiO2/GC/CH was characterized by means of tensile strength test (also used for SAW), Fourier Transform-Infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Metanil yellow removal using TiO2/GC/CH works very well at acidic pH range. The removal follows the pseudo-second-order kinetic (R2 = 0.997) and Langmuir isotherm (R2 = 0.998) modellings. High qm obtained from the metanil yellow removal under UV irradiation (qm = 171.527) proves the synergism between adsorption and photodegradation. The developed TiO2/GC/CH could be potentially used in the wastewater treatment for azo dye removal.