Facile synthesis of a ZnO-BiOI p-n nano-heterojunction with excellent visible-light photocatalytic activity.

Mengyuan Zhang,Riping Liu,Xinyu Zhang,Jiaqian Qin,Mingzhen Ma,Pengfei Yu,Bing Zhang

doi:10.3762/bjnano.9.72

Abstract

In this paper, an efficient method to produce a ZnO/BiOI nano-heterojunction is developed by a facile solution method followed by calcination. By tuning the ratio of Zn/Bi, the morphology varies from nanoplates, flowers to nanoparticles. The heterojunction formed between ZnO and BiOI decreases the recombination rate of photogenerated carriers and enhances the photocatalytic activity of ZnO/BiOI composites. The obtained ZnO/BiOI heterostructured nanocomposites exhibit a significant improvement in the photodegradation of rhodamine B under visible light (λ ≥ 420 nm) irradiation as compared to single-phase ZnO and BiOI. A sample with a Zn/Bi ratio of 3:1 showed the highest photocatalytic activity (≈99.3% after 100 min irradiation). The photodegradation tests indicated that the ZnO/BiOI heterostructured nanocomposites not only exhibit remarkably enhanced and sustainable photocatalytic activity, but also show good recyclability. The excellent photocatalytic activity could be attributed to the high separation efficiency of the photoinduced electron–hole pairs as well as the high specific area.

Highlights

The development of semiconductor photocatalysis has opened a new horizon for environmental pollution remediation and provides a potential solution to the global energy problem given the abundance and sustainability of solar energy
The results show that the degradation performance of ZnO and BiOI are quite unsatisfactory, while no concentration difference is visible without the catalyst, demonstrating the self-degradation of rhodamine B (RhB) is negligible
ZnO–BiOI heterostructured nanocomposites were successfully synthesized via a facile solution method followed by calcination, resulting in different morphology, optical properties and band gap structures by tuning the Bi/Zn molar ratio to 1:0, 1:1, 1:2, 1:3, 1:4 to 0:1

Summary

Introduction

The development of semiconductor photocatalysis has opened a new horizon for environmental pollution remediation and provides a potential solution to the global energy problem given the abundance and sustainability of solar energy. The composition of as-prepared ZnO/BiOI heterojunction nanocomposites was examined by X-ray diffraction (XRD) analysis as shown in the Figure 1.

Results

Conclusion