Tailoring the Surface Chemical Reactivity of Transition‐Metal Dichalcogenide PtTe₂ Crystals

Abstract

PtTe 2 is a novel transition-metal dichalcogenide hosting type-II Dirac fermions that displays application capabilities in optoelectronics and hydrogen evolution reaction. Here it is shown, by combining surface science experiments and density functional theory, that the pristine surface of PtTe 2 is chemically inert toward the most common ambient gases (oxygen and water) and even in air. It is demonstrated that the creation of Te vacancies leads to the appearance of tellurium-oxide phases upon exposing defected PtTe 2 surfaces to oxygen or ambient atmosphere, which is detrimental for the ambient stability of uncapped PtTe 2 -based devices. On the contrary, in PtTe 2 surfaces modified by the joint presence of Te vacancies and substitutional carbon atoms, the stable adsorption of hydroxyl groups is observed, an essential step for water splitting and the water-gas shift reaction. These results thus pave the way toward the exploitation of this class of Dirac materials in catalysis.

Metallic Twin Boundaries Boost the Hydrogen Evolution Reaction on the Basal Plane of Molybdenum Selenotellurides

“…In addition, the different functional properties of tellurides spanning from advanced electronic properties and chemical or optical activity are expected to promote the realization of a new generation of multifunctional smart devices. [24][25][26] The study of telluride chemistry is, however, still at its infancy and only few papers deal with this subject. [27][28][29] Quite recently, the formation of solid solutions of different TMCs demonstrated to be a powerful method to improve the catalytic activity.…”

Band Structure Perfection and Superconductivity in Type‐II Dirac Semimetal Ir1−xPtxTe2

“…Multiple topological nontrivial TSMs have been studied, including Dirac semimetals (DSMs), [1][2][3][4] Weyl semimetals (WSMs), [5][6][7][8][9] nodal-line semimetals, [10,11] and Lorentz invariance-breaking type-II WSMs. [24][25][26][27] In particular, intrinsic topological superconductivity (TSC) [28][29][30][31][32][33] could be induced in type-II DSMs due to a finite density of states around the Dirac points, potentially hosting Majorana modes [28][29][30][31][32][33][34][35][36][37] with possible applications in topological quantum computations. [24][25][26][27] In particular, intrinsic topological superconductivity (TSC) [28][29][30][31][32][33] could be induced in type-II DSMs due to a finite density of states around the Dirac points, potentially hosting Majorana modes [28][29][30][31]…”

“…[24] In addition, the potential applications of type-II DSMs such as Dirac materials catalysis [27] may be expected and investigated in Ir 1−x Pt x Te 2 . [24] In addition, the potential applications of type-II DSMs such as Dirac materials catalysis [27] may be expected and investigated in Ir 1−x Pt x Te 2 .…”

“…[12][13][14][15] The concept of broken Lorentz invariance also results in a new system termed type-II DSM, in which the Dirac cones are tilted significantly along specific momentum directions, [16][17][18][19][20][21][22][23] leading to a modulated effective mass and the potential for new applications. [24][25][26][27] In particular, intrinsic topological superconductivity (TSC) [28][29][30][31][32][33] could be induced in type-II DSMs due to a finite density of states around the Dirac points, potentially hosting Majorana modes [28][29][30][31][32][33][34][35][36][37] with possible applications in topological quantum computations. [38,39] Materials made of type-II DSMs have been recently discovered in the 1T-PtSe 2 family, i.e., PtSe 2 , PtTe 2 , and PdTe 2 .…”

“…In summary, the material Ir 1−x Pt x Te 2 , is an interesting platform combining the type-II Dirac cone, Fermi level tunability, and superconductivity, enabling further studies on the exotic transport properties of type-II Dirac semimetals, such as quantum oscillation with a nontrivial Berry phase, anisotropic magneto-transport, and Klein tunneling in momentum space. [24] In addition, the potential applications of type-II DSMs such as Dirac materials catalysis [27] may be expected and investigated in Ir 1−x Pt x Te 2 . Superconductivity in this material may also open a new route to the future investigation of possible TSC and Majorana physics.…”