Center for Functional Nanomaterials Seminar

Novel 2D materials are of great interest for both fundamental physics study and applications for future electronic devices. Currently, studies on 2D materials mainly focus on van der Waals (vdW) materials since the groundbreaking discovery of graphene, which presents unprecedented physics compared with the bulk. However, little exploration is conducted on 2D materials that don't naturally present themselves in stratiform structures. In this regard, the synthesis of 2D materials with desired quality is particularly important as materials to lay the foundation for future study on fundamental properties as well as exploration of potential applications. In this presentation, I will focus on developing novel approaches for the synthesis of non-metal nitrides. I demonstrate the versatility of the atomic substitution approach by successfully applying it to the synthesis of a range of metal nitrides, including metallic MoN, Mo5N6, W5N6, TiN and an III-V wide bandgap semiconductor-GaN. I carry out structural characterization and design time and temperature-dependent experiments to reveal the conversion mechanism. Raman, photoluminescence spectroscopy, and electrical measurements are employed to study the optical and electrical properties of the nitrides. Finally, I will show that the MoN prepared from atomic substitution of monolayer MoS2 displays enhanced electrochemical catalytic activity for hydrogen evolution reaction.