Improvement of Photocatalytic Performance for the g-C3N4/MoS2 Composite Used for Hypophosphite Oxidation

Wei Guan,Rui Yang,Li Zhuo,Mingshan Li,Kaiming Li,Yong Wen,Jianwei Du,Kuang He

doi:10.1155/2020/8461543

Wei Guan, Rui Yang + Show 6 more

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https://doi.org/10.1155/2020/8461543

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Abstract

The synthesized g-C3N4/MoS2 composite was a high-efficiency photocatalytic for hypophosphite oxidation. In this work, a stable and cheap g-C3N4 worked as the chelating agent and combined with the MoS2 materials. The structures of the fabricated g-C3N4/MoS2 photocatalyst were characterized by some methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectra (XPS). Moreover, the photocatalytic performances of various photocatalysts were measured by analyzing the oxidation efficiency of hypophosphite under visible light irradiation and the oxidation efficiency of hypophosphite using the g-C3N4/MoS2 photocatalyst which was 93.45%. According to the results, the g-C3N4/MoS2 composite showed a promising photocatalytic performance for hypophosphite oxidation. The improved photocatalytic performance for hypophosphite oxidation was due to the effective charge separation analyzed by the photoluminescence (PL) emission spectra. The transient photocurrent response measurement indicated that the g-C3N4/MoS2 composites (2.5 μA cm–2) were 10 times improved photocurrent intensity and 2 times improved photocurrent intensity comparing with the pure g-C3N4 (0.25 μA cm–2) and MoS2 (1.25 μA cm–2), respectively. The photocatalytic mechanism of hypophosphite oxidation was analyzed by adding some scavengers, and the recycle experiments indicated that the g-C3N4/MoS2 composite had a good stability.

Highlights

Sodium hypophosphite is the most common reducing agent during the electroless plating, generating high concentration of hypophosphite wastewater [1, 2]
The results of recycling experiments indicated that the prepared g-C3N4/MoS2 photocatalyst had a strong binding force, which effectively reduced the dissolution of the bulk g-C3N4 material during the photocatalytic process
The composite g-C3N4/MoS2 indicated higher photocatalytic performance comparing with the pure g-C3N4 and MoS2 photocatalyst

Summary

Introduction

Sodium hypophosphite is the most common reducing agent during the electroless plating, generating high concentration of hypophosphite wastewater [1, 2]. There are some shortcomings for g-C3N4 as a photocatalyst, such as low utilization rate of light and high recombination rate of photon-generated carrier [14, 15] Some methods such as structure modification [16], semiconductors coupling [17], elements, and molecular doping [18, 19] were used to modify the g-C3N4 materials to improve the photocatalytic performance of g-C3N4. Molybdenum disulfide (MoS2), a 2D metal sulfide material, has the properties of excellent stability and low band gap of 1.21.9 eV, which can be responded under visible light irradiation and worked as photocatalyst [20, 21]. A g-C3N4/MoS2 photocatalyst was prepared and shown an improved photocatalytic performance for hypophosphite oxidation under visible light irradiation. The g-C3N4/MoS2 composite was stable after recycle experiments

Experimental

Analysis of Structure and Morphology for Different

Conclusion