Hexagonal MBene (Hf₂BO₂): A Promising Platform for the Electrocatalysis of Hydrogen Evolution Reaction

Abstract

Hexagonal MAB (h-MAB) phases and their two-dimensional (2-D) derivatives (h-MBenes) have emerged as promising materials since the discovery of Ti2InB2. Herein, we identified that a possible h-MBene, 2-D Hf2BO2, can be an excellent platform for the electrocatalysis of hydrogen evolution reaction (HER) by density functional theory calculations. We proposed two approaches of transition metal (TM) modifications by atom deposition and implanting to optimize the HER performance of 2-D Hf2BO2. It is revealed that a moderate charge reduction of surface O, which is induced by the introduction of TM atoms, is conductive to a higher catalytic performance. The synergistic effect between implanted TM atoms and Hf2BO2 matrix can efficiently activate the surface by broadening O-p orbitals and shifting up p-band center, especially for V, Cr, and Mo as dopants, which can reduce the Gibbs free energy (ΔG H*) from 0.939 to −0.04, 0.05 and −0.04 eV, respectively. Interestingly, this effect works within a local region and the activity can also be evaluated by bond length of Hf–O, in addition to ΔG H*. This work suggests that due to its excellent electrocatalysis properties, h-MBenes can open up a new area for 2-D materials and will stimulate researchers to explore the synthesis of h-MAB phases and the stripping of h-MBenes.

Substitutional Doping Engineering toward W2N Nanorod for Hydrogen Evolution Reaction at High Current Density

“…Figure 4a demonstrates that the calculated ΔG H * value of Ni-W 2 N is only −0.175 eV, which is close to the firstrank value of 0 eV. 35,36 Pure W 2 N has too strong an affinity for H* (−0.256 eV). What is more, Ni-W 2 N has an excellent ΔG OH * value of −1.105 eV, which is closer to the first-rank value than that of pure W 2 N (−0.59 1 eV).…”

“…The calculation structure is exhibited in Figure S25. Figure a demonstrates that the calculated Δ G H * value of Ni-W 2 N is only −0.175 eV, which is close to the first-rank value of 0 eV. , Pure W 2 N has too strong an affinity for H* (−0.256 eV). What is more, Ni-W 2 N has an excellent Δ G OH * value of −1.105 eV, which is closer to the first-rank value than that of pure W 2 N (−0.59 1 eV). − The calculation results show that Ni doping of W 2 N can reduce the H binding energy as well as enhance the binding energy of OH and show better adsorption energy of hydrogen and hydroxide, which contributes to the excellent HER activity. − …”

A Rising 2D Star: Novel MBenes with Excellent Performance in Energy Conversion and Storage

“…This is more favorable for the H 2 adsorption and desorption processes, which significantly accelerates the HER process. Recently, Feng et al [ 220 ] chose 2D Hf 2 B as the object of study for its application in electrocatalytic HER. In this study, two TM modifications were proposed to significantly improve the catalytic activity of Hf 2 BO 2 : atom deposition of TM@Hf 2 BO 2 and atom implanting of TM-Hf 2 BO 2 .…”

M4B6X6 as a New Family of High‐Efficient Electrocatalysts: The Role of Surface Reconstruction in Water Oxidization

“…For example, MBenes (M=Sc, Ti, V, Cr, Mo, W, Mn, Tc, etc.) were investigated for application in ion‐batteries, [31,32] and used as catalysts for OER, HER, and N 2 reduction reaction (NRR) [33–36] . Borophane, M 2 B 2 and MnB 2 were also studied for ion‐batteries [37–40] .…”

“…were investigated for application in ion-batteries, [31,32] and used as catalysts for OER, HER, and N 2 reduction reaction (NRR). [33][34][35][36] Borophane, M 2 B 2 and MnB 2 were also studied for ion-batteries. [37][38][39][40] However, the catalytic properties of Boridenes have not been reported.…”