Preparation and Photocatalytic Performance of MWCNTs/TiO2Nanocomposites for Degradation of Aqueous Substrate

Qiannan Duan,Yansong Liu,Hailang Qi,Jianchao Lee

doi:10.1155/2016/1262017

Abstract

In this study, multiwalled carbon nanotubes (MWCNTs)/TiO2nanocomposites were obtained by constant volumetric wet impregnation processes. The prepared catalysts were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effect of reaction conditions on photocatalytic performance of the catalysts was investigated by the degradation of methyl orange (MO) under UV irradiation, in a new type of reactor with unique structure. The results showed that the prepared nanocomposite exhibited higher MO degradation efficiency than that of pure nano-TiO2. Besides, in batch experiments of influencing factors, including ionic strength, oxidant amount, and response times, the presence of H2O2would contribute to increasing the MO degradation rate of MWCNTs/TiO2samples. Ionic concentration and long reaction times are adverse to the MO degradation in the processes.

Highlights

The color and high COD of dye wastewater cause serious environmental contamination problems
A nitric acid washing procedure was achieved for the acid treatment of multiwalled carbon nanotubes (MWCNTs). 2.0 g of raw MWCNTs was immersed into 50 mL of concentrated nitric acid, and the mixture was sonicated in an ultrasonic washer for 1 h to form oxygenated functionalities on the MWCNTs’ surface
The aggregation (4, Figure 3(c)) was attributed to TiO2 nanoparticles which were annealed under the calcining temperature of 823 K for 2 h during the preparation progress of TiO2 thin films

Summary

Introduction

The color and high COD of dye wastewater cause serious environmental contamination problems. Modern dyes are diverse and they are often resistant to long-term exposure in sunlight, water, and other atrocious conditions, making the treatment of dye wastewater more difficult [1]. An effective decolorization method is needed to remove the toxic or carcinogenic dye residues and their by-products, which is an important issue in the field of wastewater treatment. Methyl orange (MO), with one azo bond (–N=N–) in association with one aromatic system, is a sort of typical azo dyestuff and is a model compound of a series of common water soluble azo dyes widely used in chemistry, textiles, and paper industries [2]

Methods

Results

Conclusion