Engineering Polymorphs in Colloidal Metal Dichalcogenides: Precursor Mediated Phase Control, Molecular Insights into Crystallisation Kinetics and Promising Electrochemical Activity
Niraj Nitish Patil a, Nilotpal Kapuria a, Abinaya Sankaran a, Fathima Laffir a, Hugh Geaney a, Edmond Magner a, Micheal Scanlon a, Kevin Ryan a, Shalini Singh a
a Department of Chemical Sciences and Bernal Institute, University of Limerick, V94 T9PX, Limerick, Ireland
Materials for Sustainable Development Conference (MATSUS)
Proceedings of MATSUS23 & Sustainable Technology Forum València (STECH23) (MATSUS23)
#NCFun23 - Fundamental Processes in Nanocrystals and 2D Materials
València, Spain, 2023 March 6th - 10th
Organizers: Valerio Pinchetti and Shalini Singh
Poster, Niraj Nitish Patil, 326
Publication date: 22nd December 2022

Two-dimensional (2D) transition metal dichalcogenides (TMD) such as MoS2, WS2, ZrS2, and TiS2 have emerged as intriguing classes of functional materials due to their distinct chemical and physical properties.[1] Their peculiar structure and exceptional electronic, optical and mechanical properties have stimulated various applications in catalysis, energy storage, electronics, and optoelectronics fields. [2] TMD can exist in several structural polymorphs, including 2H, 1T and 3R. [3] However, due to the thermodynamic stability of 2H over other polymorphs, fine synthesis control over polymorphism in TMD is challenging, restricting the entire range of characteristics associated with other polymorphs. Herein, we present a solution-based crystal phase engineering approach for layered transition metal disulphide nanosheets by modulating the reactivity of the molecular precursors. By tuning precursor-ligand chemistry, 2H, 1T' and polytypic MoS2 and WS2 are synthesised. The ability to selectively vary the reactivity of S and metal precursors provided control over the amount of certain phases in synthesised nanosheets. The production of 1T' is promoted by the highly reactive metal and S source, whereas less reactive sources lead to the formation of thermodynamically stable 2H. The electrocatalytic characteristics of the synthesised TMDs were investigated for the oxygen reduction process. The polytypic MoS2 with a 2H-1T' combination had the highest positive potential of 0.82 V (vs RHE). The insights this work provides will be instrumental in designing scalable solution-based pathways to control polytypes in layer transition metal dichalcogenides. Furthermore, this synthesis approach has the potential to be extended to multiple TMDs, enabling exquisite control over polymorphism in TMDs.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info