One-Step Hydrothermal Fabrication of Three-dimensional MoS2 Nanoflower using Polypyrrole as Template for Efficient Hydrogen Evolution Reaction

Xin Lu,Xueji Zhang,Xuanhui Qu,Haifeng Dong,Wenhao Dai,Yingwu Lin,Xin Chen

doi:10.1038/srep42309

Abstract

Herein, a facile and cost-effective strategy for hydrothermal synthesis of three-dimensional (3D) MoS2 with adequate active edge sites and advanced hydrogen evolution reaction (HER) performance using polypyrrole (PPy) as template is reported. The MoS2 is first thermally nucleated using hexaammonium heptamolybdate tetrahydrate (NH4)6Mo7O24·4H2O and thiourea as precursor in the presence of PPy, and then they are further annealed to remove PPy at higher temperature to generate 3D MoS2-P. Morphology and composition characterizations reveal that the 3D MoS2-P exhibits a nanoflower morphology. It presents larger stretched “thin folding leaves” and higher mesoporous volume of 0.608 cm3 g−1 than the MoS2 without PPy as template. Importantly, the 3D MoS2-P shows enhanced HER catalytic activity (onset potential at −100 mV) than previously reports that MoS2-based HER catalysts. The large “thin folding leaves” possessing efficient edge active sites and defects are responsible to for the enhanced HER performance, while the high mesoporous volume facilitates the transfer of reaction substrate. Our study provides a facile and cost-effective method for synthesis of 3D MoS2 with advanced HER performances, which has great potential for larger-scale production and practical industrial applications.

Highlights

The one-step hydrothermal synthesis method is schematically illustrated in Fig. 1. (NH4)6Mo7O24·4H2O and thiourea were chosen as the precursor for large-quantity of MoS2 preparation in the presence of PPy, The PPy was employed as the template to generate a MoS2 structure with large surface area and adequate active edges
The Scanning electron microscope (SEM) image (Fig. S1) shows that the morphology of PPy is an irregular sphere with rough surface, which provide a template for the formation of nanoflower of MoS2-P (Fig. 2b)
These results revealed that the PPy template effectively inhibited the aggregation of MoS2 during hydrothermal synthesis process

Summary

Introduction

Kibsgaard et al engineered the surface structure of MoS2 to preferentially expose edge sites for improved catalytic activity by successfully synthesizing contiguous large-area thin films of a highly ordered double-gyroid MoS2 with nanopores[23]. Various 3D MoS2 structures with high-surface and exposed active sites present great prospect in large-scale and practical applications. Comprehensive characterizations revealed a nanoflower morphology of the resulting MoS2-P It presented larger area “thin folding leaves” and much more mesoporous pore than the counterpart without PPy as template. The PPy template could generate nanoflower morphology with larger stretched “thin folding leaves” and higher mesoporous volume as well as much more tortuous and cleaved lattice structures than the MoS2 without PPy as template. The proposed method is a facile and cost-effective, providing great potential for larger-scale production of 3D MoS2 with advanced HER performances and practical industrial application

Methods

Results

Conclusion