Role of RGO support and irradiation source on the photocatalytic activity of CdS-ZnO semiconductor nanostructures.

Suneel Kumar,Vaidyanathan Sivakumar,Vipul Sharma,Gurunarayanan Harith,Rahul Sharma,Venkata Krishnan

doi:10.3762/bjnano.7.161

Abstract

Photocatalytic activity of semiconductor nanostructures is gaining much importance in recent years in both energy and environmental applications. However, several parameters play a crucial role in enhancing or suppressing the photocatalytic activity through, for example, modifying the band gap energy positions, influencing the generation and transport of charge carriers and altering the recombination rate. In this regard, physical parameters such as the support material and the irradiation source can also have significant effect on the activity of the photocatalysts. In this work, we have investigated the role of reduced graphene oxide (RGO) support and the irradiation source on mixed metal chalcogenide semiconductor (CdS–ZnO) nanostructures. The photocatalyst material was synthesized using a facile hydrothermal method and thoroughly characterized using different spectroscopic and microscopic techniques. The photocatalytic activity was evaluated by studying the degradation of a model dye (methyl orange, MO) under visible light (only) irradiation and under natural sunlight. The results reveal that the RGO-supported CdS–ZnO photocatalyst performs considerably better than the unsupported CdS–ZnO nanostructures. In addition, both the catalysts perform significantly better under natural sunlight than under visible light (only) irradiation. In essence, this work paves way for tailoring the photocatalytic activity of semiconductor nanostructures.

Highlights

In the past decade, there has been an increased interest in the photocatalytic degradation of various kinds of organic pollutants in water and soil [1]
We focused our studies on determining the role of the reduced graphene oxide (RGO) support and the irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures
In the powder X-ray diffraction (XRD) data of nanocomposites, all peaks that are ascribable to ZnO and CdS structures are evident, which demonstrates that the same crystal phases are retained in both binary (CdS–ZnO) and ternary (CdS–ZnO–RGO) nanocomposites

Summary

Introduction

There has been an increased interest in the photocatalytic degradation of various kinds of organic pollutants in water and soil [1]. In this work, , the preparation and detailed characterization of binary and ternary nanocomposites are presented and their photocatalytic activity have been demonstrated with respect to the degradation of methyl orange (MO) dye, both under visible light (only) irradiation from a solar simulator and natural sun light.

Results

Conclusion