Janus MoPC Monolayer with Superior Electrocatalytic Performance for the Hydrogen Evolution Reaction

Abstract

Designing the earth’s abundant and high-performance electrocatalysts, which possess high stability, excellent electrical conductivity, inherent active sites, and catalytic activity identical with Pt, is challenging but crucial for the hydrogen evolution reaction (HER). By first-principles structure search simulations, we identify a new two-dimensional (2D) MoPC material with the Janus structure as a promising catalyst. This novel 2D monolayer has superior stability and metallic conductivity. Especially, it exhibits a remarkable HER catalytic activity, where all of the constituent atoms, including Mo, P, and C, can uniformly act as active sites in view of the near-zero ΔG H* value. Its active site density counts up to 1.46 × 1015 site/cm2, larger than that of many reported materials and even comparable to Pt. The excellent HER catalytic activity can also be maintained at a very high H coverage with or without external strain. The MoPC monolayer can produce H2 spontaneously through the favorable Volmer–Heyrovsky pathway. The detailed catalytic mechanism behind the high HER activity has been also analyzed. Our work provides a feasible action for the experimental synthesis of excellent HER catalysts.

Versatile transition metal monolayers with catalytic and superconducting properties: a computational study

“…Due to the occupation of d orbitals, the transition metals have valence electrons that not only may promote electron-phonon coupling and improve the superconducting temperature, according to the Bardeen-Cooper-Schrieffer (BCS) theory, 20 but also yield a better catalytic performance. [21][22][23][24][25][26] The distinct aromatic network structures also could endow this type of compound with novel properties, e.g., catalytic properties. This unique structural motif allows for great freedom to modulate the catalytic active sites and electronic features.…”

2D Metal-Free BSi5 with an Intrinsic Metallicity and Remarkable HER Activity

“…Material stability (e.g., cohesive energy, dynamical stability, thermal stability, and mechanical stability) is a crucial factor for HER catalysts . The calculated cohesive energies ( E coh ) of the BSi 5 , BSi 4 , and BSi 3 monolayers are 4.25, 4.17, and 4.08 eV/atom, which are comparable to SiP (4.19 eV/atom), B 2 P 6 (4.14 eV/atom), and silicene (3.94 eV/atom) .…”

“…High electrical conductivity in materials is indispensable for high-performance HER . The calculated electron band structures of the BSi x ( x = 3–5) monolayers exhibit inherent metallicity in terms of several bands crossing the Fermi level (Figure S5).…”

“…67,70 High electrical conductivity in materials is indispensable for high-performance HER. 23 The calculated electron band structures of the BSi x (x = 3−5) monolayers exhibit inherent metallicity in terms of several bands crossing the Fermi level (Figure S5). Based on the calculated partial density of states (PDOS), there appears to be a strong hybridization between B p z and Si p z orbitals as well as interatomic Si p z orbitals, indicating the formation of a delocalized π bond, which contributes to the metallicity (Figure 2a and Figure S6).…”

“…The large specific surface area and controllable electronic properties of two-dimensional (2D) materials have offered distinct advantages and promising developments in electrocatalysis . Thus far, a plethora of 2D metal-based electrocatalysts have been proposed, − especially for transition metal-based materials (e.g., transition metal dichalcogenides, − MXene, − transition metal phosphides, − transition metal carbide, and transition metal borides − ). Some of them have been verified to have the ability to split water, but their active sites are typically located at the edges, defects, and doped atoms.…”