David Lewis1

1, University of Manchester, Manchester, , United Kingdom

Layered bulk materials have attracted much attention for various technological applications including tribology and catalysis [1]. One of the most recent applications is in their study in the two-dimensional limit i.e. atomically thick materials such as graphene. Inorganic graphene analogues such as few layer molybdenum disulphide, black phosphorus and main group chalcogenides have also been the subjects of much intense research as two-dimensional semiconductors that would be complementary to graphene in a future electronics industry [2]. We have devised top-down routes to 2D black phosphorus [3] and tin(II) sulphide [4] both of which have layer dependent band gaps. However, these top-down processes suffer from a major drawback: often commercially available layered bulk crystals are used as feedstock and this inherently limits the palette of two-dimensional materials available for study without resorting to expensive processing via CVD.

As a solution to this, we have devised new routes based on solventless thermolysis of metal-organic precursors that can produce layered materials in bulk at relatively low temperatures and in relatively high purity. Because the precursors used are on the molecular scale, we can control the extent of doping or alloying of materials and this then widens range of layered materials available for exfoliation. I will present the synthesis of layered transition metal oxides and chalcogenides [5] and main group chalcogenide alloys [6], the latter also studied as post-processed 2D materials as an example of a new route to 2D materials with wide applicability.

[1] Tedstone et al. Chem. Mater. 2016, 28, 1965.
[2] Tedstone et al. Nanoscience Vol 4 (RSC Specialist Periodical Reports), 2017, 4, 108.
[3] Brent et al. Chem Commun. 2014, 50, 13338.
[4] Brent et al. J. Am Chem. Soc. 2015, 126, 9413.
[5] Zeng et al. Chem. Commun. 2019 ,55, 99.
[6] Norton et al. Chem. Sci. 2019, 10, 1035.