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

^aDepartment 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.

References:

[1] Tan, C.; Zhang, H. Two-dimensional transition metal dichalcogenide nanosheet-based composites. Chem. Soc. Rev. 2015, 44(9), 2713-2731.

[2] Lv, R.; Robinson, J. A.; Schaak, R. E.; Sun, D.; Sun, Y.; Mallouk, T. E.; Terrones, M. Transition metal dichalcogenides and beyond: synthesis, properties, and applications of single-and few-layer nanosheets. Acc. Chem. Res. 2015, 48(1), 56-64.

[3] Kuc, A; Heine, T. The electronic structure calculations of two-dimensional transition-metal dichalcogenides in the presence of external electric and magnetic fields. Chem. Soc. Rev. 2015, 44(9), 2603-2614.

nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.

MATSUS

Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.

International Conference on Hybrid and Organic Photovoltaics

International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.

Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics

The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.

International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics

The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.