Constructing Tunable Electrides on Monolayer Transition Metal Dichalcogenides

Electrides have emerged as promising materials with exotic properties due to the presence of localized electrons that are detached from all atoms. Despite the continuous discovery of new electrides, most are based on uncommon compositions, and their applications require inert surface structures to passivate reactive excess electrons. In this study, we demonstrate an alternative approach to achieving tunable electrides. We report that monolayer transition metal dichalcogenides (TMDCs) exhibit weak electride characteristics, a remnant of the electride features of the transition metal sublattice. By introducing chalcogen vacancies, we observe an enhancement in these electride characteristics, making them comparable to those of known electrides. Given that precise control over chalcogen vacancy concentration has been experimentally achieved, we propose that TMDCs can be used to create electrides with adjustable intensities. Additionally, we show that the electride states at chalcogen vacancies in monolayer TMDCs play a significant role in catalyzing hydrogen evolution reactions.

M.M. and A.E. acknowledge the support of the DoD Research and Education Program for Historically Black Colleges and Universities and Minority-Serving Institutions (HBCU/MI) Basic Research Funding under grant No. W911NF2310232., the support of the National Science Foundation (NSF) funds DMR 1848141 and OAC 2117956, and the Camille and Henry Dreyfus Foundation.