Graphitic carbon nitride nanocrystals decorated AgVO3 nanowires with enhanced visible-light photocatalytic activity

doi:10.1016/j.catcom.2016.10.021

Catalysis Communications

Volume 89, 10 January 2017, Pages 96-99

https://doi.org/10.1016/j.catcom.2016.10.021 Get rights and content

Highlights

•
Heterostructured g-C₃N₄/AgVO₃ photocatalyst was successfully synthesized.
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The nanoheterostructure included g-C₃N₄ nanocrystals assembling on the surface of AgVO₃ nanowires.
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g-C₃N₄/AgVO₃ photocatalyst exhibited enhanced photocatalytic performance.

Abstract

In the present study, a novel graphitic carbon nitride (g-C₃N₄) nanocrystals/AgVO₃ photocatalyst was successfully synthesized by a simple two-step method. The as-prepared g-C₃N₄/AgVO₃ heterostructures included g-C₃N₄ nanocrystals assembling uniformly on the surface of AgVO₃ nanowires. The successful modification of AgVO₃ nanowires by g-C₃N₄ nanocrystals was found to improve the photocatalyst activity significantly because of enhanced light absorption and improved separation of photo-generated electron–hole pairs.

Graphical abstract

Introduction

The development of visible-light-driven photocatalysts with excellent performance and good stability is a prerequisite for harvesting more sunlight and realizing efficient photocatalysis [1], [2]. AgVO₃ has been demonstrated to be an efficient visible photocatalyst, due to its narrow band gap and well crystallization [3]. However, poor quantum yield and poor visible light absorption efficiency are still challenges to improve the photocatalytic performance of AgVO₃ for meeting the practical application requirements. To solve this issue, great effort has been devoted to the exploration and preparation of novel photocatalytic materials for improving photocatalytic performance of the catalysts [3], [4], [5], including dye-sensitization [5], [6], [7], development of new narrow-band gap semiconductors and band engineering of semiconductor heterojunction [8], [9], [10], [11], [12]. Among these works, the construction of a semiconductor heterojunction has attracted great attention because of its perfect effectiveness in improving photocatalytic activity [13], [14], [15], [16], [17].

Recently, graphitic carbon nitride (g-C₃N₄) as a metal-free polymeric semiconductor has attracted much attention [18]. In this context, it would be of great significance to develop g-C₃N₄ based materials for photocatalysis application. Recently, there are a few reports concentrated on g-C₃N₄ based photocatalysts, such as g-C₃N₄ quantum dots/g-C₃N₄, g-C₃N₄/graphene, g-C₃N₄/BiPO₄, and g-C₃N₄/TiO₂ [19], [20], [21], [22]. Herein, we report a successful attempt at the fabrication of g-C₃N₄/AgVO₃ nanowires via a facile in situ precipitation method, and the photocatalytic activity of the nanoheterostructures was investigated by measuring the degradation of rhodamine B (Rh B) under visible light (λ > 420 nm).

Section snippets

Preparation of g-C₃N₄ nanocrystals

Bulk g-C₃N₄ was prepared by heating melamine for 4 h to 550 °C and kept at this temperature for another 4 h in air [19]. The g-C₃N₄ nanocrystals were prepared by using the Yu method [19]: First, 1 g of bulk g-C₃N₄ was treated in the mixture of concentrated sulfuric acid (H₂SO₄) (20 mL) and nitric acid (HNO₃) (20 mL) for about 2 h at room temperature. The mixture was then diluted with deionized water (1 L) and washed for several times. Second, 50 mg of the obtained solid was dispersed in 30 mL

Results and discussion

Fig. 1 shows the XRD patterns of the as-prepared AgVO₃, g-C₃N₄, and g-C₃N₄ (2%)/AgVO₃ samples. The diffraction peaks for the AgVO₃ sample are well indexed to monoclinic structure of β-AgVO₃ (JCPDS: 29-1154) [3]. When coupling the two compounds, the main characteristic diffraction peaks of AgVO₃ did not change obviously. In addition, there is no any diffraction peaks of g-C₃N₄ can be detected for g-C₃N₄/AgVO₃ sample, which may be resulted from small crystal size or low percentage of g-C₃N₄

Conclusions

High-efficiency visible-light-driven g-C₃N₄/AgVO₃ photocatalyst was successfully synthesized. The as-prepared g-C₃N₄/AgVO₃ nanowires exhibited excellent photocatalytic efficiency on the decolorization of Rh B, which was superior to those of pure g-C₃N₄ and AgVO₃. The enhanced photocatalytic activity of the g-C₃N₄/AgVO₃ may originate from the efficient separation of photogenerated electron–hole pairs through the heterostructure composed of g-C₃N₄ and AgVO₃.

Acknowledgment

This work was supported by the National Natural Science Foundation of China (21407059, 21576112, 51404108, 61308095), the Science Development Project of Jiangsu Province (BK20140527), and Science and Technology Research Project of the Department of Education of Jilin Province (2015220).

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Short communicationGraphitic carbon nitride nanocrystals decorated AgVO3 nanowires with enhanced visible-light photocatalytic activity

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Preparation of g-C3N4 nanocrystals

Results and discussion

Conclusions

Acknowledgment

Chem. Eng. J.

Appl. Catal. B Environ.

Sep. Purif. Technol.

Appl. Catal. B Environ.

Mater. Lett.

Appl. Catal. B Environ.

Catal. Comm.

Adv. Mater.

Am. Chem. Soc.

J. Mater. Chem. A

Chem. Soc. Rev.

Energy Environ. Sci.

Energy Environ. Sci.

Chem. Soc. Rev.

Short communication
Graphitic carbon nitride nanocrystals decorated AgVO₃ nanowires with enhanced visible-light photocatalytic activity

Preparation of g-C₃N₄ nanocrystals