Fabrication of transition metal dichalcogenides quantum dots based on femtosecond laser ablation

Yanmin Xu,Xiaoyu Li,Huanhuan Xu,Lihe Yan

doi:10.1038/s41598-019-38929-5

Yanmin Xu, Xiaoyu Li + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-38929-5

Copy DOI

Journal: Scientific Reports	Publication Date: Feb 27, 2019
Citations: 60	License type: open-access

Affiliation: Xi'an Jiaotong University

Abstract

As heavy metal-free quantum dots, transition metal dichalcogenides (TMDs) and boron nitride (BN) quantum dots (QDs) have aroused great interest due to features such as good thermal conductivity, chemical stability, and unique optical properties. Although TMDs have been synthesized using different methods, most of these methods require time-consuming or complex steps, limiting the applications of TMDs. We propose a fast and simple method for the synthesis of high-quality molybdenum disulfide (MoS2) QDs and tungsten disulfide (WS2) QDs based on femtosecond laser ablation and sonication-assisted liquid exfoliation. The prepared MoS2 QDs and WS2 QDs were characterized by transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The resulting products possessed few-layered thickness with an average size of 3.7 nm and 2.1 nm. Due to the abundance of functional groups on their surface, the MoS2 QDs and WS2 QDs showed bright blue-green luminescence under UV irradiation. Our method offers a facile and novel synthetic strategy for TMDs QDs and other two-dimensional nanomaterial quantum dots, such as boron nitride quantum dots (BNQDs).

Highlights

Following the successful application of graphene, great attention has been paid to other layered inorganic graphene analogues due to their peculiar and fascinating physical properties that are correlated with their 2D ultrathin atomic layer structure
Our method is a good candidate for the fabrication of high-quality transition metal dichalcogenides (TMDs) QDs as well as boron nitride quantum dots (BNQDs)
The TMDs QDs were prepared by femtosecond laser ablation combined with sonication-assisted liquid exfoliation of bulk TMDs in NMP, a schematic diagram of the process is shown in Fig. 1, where M represents Mo and W elements

Summary

Introduction

Following the successful application of graphene, great attention has been paid to other layered inorganic graphene analogues due to their peculiar and fascinating physical properties that are correlated with their 2D ultrathin atomic layer structure. When the femtosecond pulses are injected into the targets, multiphoton-absorption ionization occurs, and a plasma plume is formed in a high temperature and high pressure environment[21,22] Under these extreme conditions, the nanoparticles can be produced through Coulombic explosion, and surface functionalization of the nanoparticles occurs simultaneously[23]. We designed a facile route to synthesize the TMDs QDs through femtosecond laser ablation combined with sonication-assisted liquid exfoliation. Using this method, bulk TMDs were first tailored into small nanoparticles using femtosecond laser ablation and exfoliated into few-layered QDs by ultrasonic processing in liquid. The TMDs QDs fabricated by femtosecond laser ablation exhibited good dispersibility, high purity, bright fluorescence, and low toxicity. Our method is a good candidate for the fabrication of high-quality TMDs QDs as well as boron nitride quantum dots (BNQDs)

Methods

Results

Conclusion