Efficient and Rapid Photocatalytic Degradation of Methyl Orange Dye Using Al/ZnO Nanoparticles.

Piangjai Peerakiatkhajohn,Jung-Ho Yun,Jung-Hoon Sul,Teera Butburee,Supphasin Thaweesak

doi:10.3390/nano11041059

Abstract

ZnO and Aluminum doped ZnO nanoparticles (Al/ZnO NPs) were successfully synthesized by the sol-gel method. Together with the effect of calcination temperatures (200, 300 and 400 °C) and Al dosage (1%, 3%, 5% and 10%) on structural, morphological and optical properties of Al/ZnO NPs, their photocatalytic degradation of methyl orange (MO) dye was investigated. The calcination temperatures at 200, 300 and 400 °C in forming structure of ZnO NPs led to spherical nanoparticle, nanorod and nanoflake structures with a well-crystalline hexagonal wurtzite, respectively. The ZnO NPs calcined at 200 °C exhibited the highest specific surface area and light absorption property, leading to the MO removal efficiency of 80% after 4 h under the Ultraviolet (UV) light irradiation. The MO removal efficiency was approximately two times higher than the nanoparticles calcined at 400 °C. Furthermore, the 5% Al/ZnO NPs exhibited superior MO removal efficiency of 99% in only 40 min which was approximately 20 times enhancement in photocatalytic activity compared to pristine ZnO under the visible light irradiation. This high degradation performance was attributed to the extended light absorption, narrowed band gap and effective suppression of electron–hole recombination through an addition of Al metal.

Highlights

IntroductionEspecially methyl orange, are mainly used in the textile, paper, synthetic leather and food industry due to high chemical stability [1,2]
The influence of various calcination temperatures, at 200, 300 and 400 ◦ C, on the crystallinity, morphological, optical properties and photocatalytic activity of methyl orange (MO) dye was investigated for ZnO NPs
Calcination at 200 ◦ C led to the formation of compact structures composing highly uniform spherical ZnO NPs

Summary

Introduction

Especially methyl orange, are mainly used in the textile, paper, synthetic leather and food industry due to high chemical stability [1,2]. Effluents containing dyes discharged into surface and ground water can lead to very serious environmental problems such as mutagenic and carcinogenic to humans and aquatic organisms [3,4]. To reduce the harmful effects of these pollutants on the environment and follow stringent environmental regulations, the research on treatment of azo dyes in wastewater has been intensified. Various traditional treatment methods for removing azo dyes in wastewater such as physical [5,6], chemical [7,8] and biological [9,10] methods have been explored

Methods

Results

Conclusion