Environmentally Benign Organic Dye Conversion under UV Light through TiO2-ZnO Nanocomposite

Sandip M Deshmukh,Sambhaji R Bamane,Sanjay M Khetre,Shoyebmohamad F Shaikh,Mohaseen S Tamboli,Chang-Duk Kim,Sudhir S Arbuj,Santosh B Babar,Nguyen Tam Nguyen Truong,Asiya M Tamboli

doi:10.3390/met11111787

Abstract

In this work, we developed a very simple and novel approach for synthesizing TiO2-ZnO nanocomposites via the urea-assisted thermal decomposition of titanium oxysulphate and zinc acetate at different weight ratios. The synthesized nanocomposite samples were studied by means of HR-TEM, XRD, STEM, UV–Vis DRS, PL and EDS. The observed results demonstrate that the TiO2-ZnO nanocomposite consists of an anatase crystal phase of TiO2 with a crystallite size of 10–15 nm. Combined characterization, including UV–Vis DRS, STEM, EDS and HR-TEM, revealed the successful formation of a heterojunction between TiO2 and ZnO and an improvement in UV spectrum absorption. The photocatalytic activity was explored using MO degradation under ultraviolet light illumination. The results of the optimized TiO2-ZnO nanocomposite show excellent photocatalytic activity and photostability over a number of degradation reaction cycles. In addition, the current approach has immense potential to be used as a proficient method for synthesizing mixed metal oxide nanocomposites.

Highlights

The major pollutants released into the ecosystem due to increased population and industrialization have turned out to be an environmental concern
Among the various metal oxides, TiO2 has been used as a photocatalytic material with great potential due to its excellent photocatalytic activity, wide energy band gap (3.2 eV), nontoxic nature, chemical stability and cost effectiveness [9]
The TZU85, TZU80 and TZU75 nanocomposite samples show the slight appearance of the characteristic peaks of wurtzite ZnO, ranging from 30◦ to 38◦, which correspond to the reflection planes of (100), (002) and (101)

Summary

Introduction

The major pollutants released into the ecosystem due to increased population and industrialization have turned out to be an environmental concern. Advanced oxidative methods such as semiconductor metal oxide-based photocatalysis have received enormous attention for their effective degradation of pollutants present in air, water and soil This technique is low cost, is environmentally friendly, can function at ambient reaction conditions and is useful for a wide range of pollutants [1,2,3]. These strategies possess some drawbacks such as the fact that they are time consuming and costly and involve hazardous substrates and complicated reaction procedures In this regard, we have developed a thermal decomposition approach for the large-scale synthesis of the nanostructured TiO2-ZnO heterostructure as a rapid, easy, low-cost and eco-friendly technique.

Characterization

Evaluation of Photocatalytic Performance

XRD Analysis

PL Spectra

Photocatalytic Degradation of Methyl Orange Using UV–Visible Light