Invited
Nanostructures of layered materials: controlling growth schemes, morphology and catalytic activity

Layered transition metals dichalcogenides (TMDs) are promising catalysts, mainly for the hydrogen evolution reaction. Although they have been extensively studied for a few decades now, even today new fabrication routes are still explored to improve properties and to gain precise control of their morphology. Here, the formation of ternary compounds of TMDs by wet chemistry will be described. The growth mechanism, which facilitates the formation of specific structures, is the key feature to design materials with desired properties. Specifically, the doping of TMDs with other transition metals and the impact it has on their catalytic properties for hydrogen production will be presented. This growth mechanism allows for facile doping of the materials by adding the dopants either at the beginning or at the end of the reaction, thus forming a homogenous material or a graded one.

We have used this approach to dope MoSe₂ with several transition metals, and significantly improving its catalytic activity towards hydrogen production. The underlying mechanisms for such enhancement will be discussed. Moreover, we formed core-shell morphologies and revealed additional activation mechanisms for MoS₂. Beyond the well-researched MoS₂ and MoSe₂, I will present other layered structures such as WSe₂ and Bi₂Se₃ and their properties.