Controlled synthesis and layer-numberdependent catalytic properties of few-layered MoS<sub>2</sub>/CdS van der Waals heterostructures for efficient photocatalytic H<sub>2</sub> evolution

Shahid Iqbal

doi:10.21767/2472-1123-C1-021

Controlled synthesis and layer-numberdependent catalytic properties of few-layered MoS₂/CdS van der Waals heterostructures for efficient photocatalytic H₂ evolution

2^nd Edition of EuroSciCon Conference on Chemistry
February 19-20, 2019 | Prague, Czech Republic

Shahid Iqbal

Xi'an Jiaotong University, China

Posters & Accepted Abstracts: J Org Inorg Chem

DOI: 10.21767/2472-1123-C1-021

Abstract

In a typical photocatalytic reaction, efficient solar light harvesting and charge generation, as well as effective charge transport, are key factors that determine the efficiency of the photocatalytic system for H2 production. Atomically layered heterostructures have attracted significant research interest due to their unique layer-dependent catalysis and electronic properties. Previous studies have reported that the catalytic properties of MoS₂ layered materials are highly dependent on the number of layers, and the difficulty of controlling the number of layers over a substrate has been a bottleneck for widespread use. Therefore, developing a simple, facile and environmentally friendly method to fabricate van der Waals heterostructures (vdWHs) with precisely controlled MoS₂ layers for achieving highly efficient H2 generation is still a challenge. Here, we report for the first time that the H2 bubbles generated by photocatalytic water splitting are effective in the layer-by-layer exfoliation of MoS₂ nanocrystals (NCs) into few layers (Figure 1). The as obtained few layers can be in situ assembled with CdS nanosheets (NSs) into vdWHs of few-layered MoS₂/CdS NSs which, in turn, are effective in charge separation and transfer, leading to enhanced photocatalytic H₂ production activity. The few-layered MoS₂/CdS vdWHs exhibited a H₂ evolution rate of 140 mmol g(CdS)-1 h-1 and achieved an apparent quantum yield of 66% at 420 nm. This study provides a new strategy for the design of noble-metal-free few-layered MoS₂/CdS vdWH systems for photocatalytic H₂generation. We believe that this bubble exfoliation strategy can be extended to a range of other layered transition metal dichalcogenide compounds