TiO2-graphene/chitosan nanocomposite: preparation and its application for removal of anionic dyes

Abstract

In this work, TiO2-graphene/chitosan nanocomposite with high photocatalytic activity was successfully synthesized and characterized by various analyses such as XRD, TEM, SEM, EDX and DRS. The photocatalytic activity was tested vs. removal of methyl red as ananionic dye under black light radiation. Based on the results, TiO2-graphene/chitosan nanocomposite could effectively remove methyl red, and demonstrate an excellent photocatalytic enhancement over TiO2 and TiO2-graphene samples. The degradation reaction fit well to a Langmuir-Hinshelwood kinetic model implying that the reaction rate is depended on the initial adsorption step. An artificial neural network (ANN) comprising four input variables (TiO2-graphene/chitosan dosage, initial dye concentration, reaction time and temperature of the solution), eight neurons and an output variable (Removal efficiency %) was optimized, tested and validated for methyl red degradation by the prepared TiO2-graphene/chitosan nanocomposite. The results showed that the predicted data from the designed ANN model are in good agreement with the experimental data with a correlation coefficient (R2) of 0.9831. Based on the results, reaction time is the most influential variable and the temperature of solution is the less influential parameter in the removal efficiency of methyl red.