Low-Temperature Synthesis Strategy for MoS2 Slabs Supported on TiO2(110)

Mahesh K Prabhu,Irene M N Groot

doi:10.3390/surfaces3040041

Abstract

MoS2 supported on oxides like TiO2 has a broad range of applications. The atomic structure of this system is therefore very useful to study. Previous research work in this area has made use of high-temperature synthesis methods, while the preparation of an MoS2/TiO2 in very important applications, such as catalysis, makes use of a low-temperature synthesis method. In this work, we investigate a low-temperature synthesis strategy for MoS2 slabs supported on rutile TiO2(110). Using scanning tunneling microscopy and X-ray photoelectron spectroscopy, we demonstrate that not only flat MoS2 slabs with irregular shapes but also MoSx stripes with a large number of coordinatively unsaturated Mo atoms are formed. In particular, it becomes evident that, for atomic structural characterization of MoS2/TiO2 and similar oxide-supported systems grown by low-temperature synthesis methods, the surface structure of the support becomes highly relevant.

Highlights

Nanostructured MoS2 /TiO2 composites have attracted a lot of interest as a model system for applications in electronics [1,2,3], photovoltaics [4], electrocatalysis [5], and heterogeneous catalysis [6], combining a transition metal dichalcogenide (TMDC) and a wide-bandgap semiconductor
We show that our synthesis procedure yields irregular shaped MoS2 slabs with their basal planes lying flat h on i the substrate and “edge-on” MoSx stripes forming as elongated structures aligned along the 110 direction of the TiO2 (110) substrate
We have presented a low-temperature synthesis strategy for MoS2 slabs supported on TiO2 (110), using partially oxidized Mo nanoparticles as a precursor

Summary

Introduction

Nanostructured MoS2 /TiO2 composites have attracted a lot of interest as a model system for applications in electronics [1,2,3], photovoltaics [4], electrocatalysis [5], and heterogeneous catalysis [6], combining a transition metal dichalcogenide (TMDC) and a wide-bandgap semiconductor. The MoS2 /TiO2 system has found application as an efficient hydrogen evolution reaction (HER) catalyst [10]. Many fundamental properties of the MoS2 -TiO2 system, especially those relevant for catalysis, such as the atomic structure and reactivity of the edges, are disputed due to the difficulty of resolving the edge structure with sufficient contrast in conventional characterization techniques, such as electron microscopy [11,12]. Kibsgaard et al [6] have shown that the morphology of

Methods

Results

Conclusion