Abundant Vanadium Diboride with Graphene-like Boron layers for Hydrogen Evolution

Abstract

We report on the design of abundant and highly active VB 2 for hydrogen production. Density functional theory (DFT) calculations have predicted very high HER activity of the graphene-like B-layer, the V-terminated {100} layer, and the mixed V/B-terminated {101} layer of VB 2 . Bulk samples and nanoparticles of VB 2 were synthesized and tested for their HER performance. The results indicate that both bulk and nano-VB 2 are active for HER, consistent with theoretical predictions. In addition, the HER activity of VB 2 is significantly increased at the nanoscale if compared to the bulk, reaching an overpotential of 192 mV at 10 mA/cm 2 current density. Increased surface area and higher density of active sites are responsible for the higher nanoscale activity, making nano-VB 2 the best HER boride to date in terms of abundance, stability, and activity in acidic solution.

High‐Current‐Density HER Electrocatalysts: Graphene‐like Boron Layer and Tungsten as Key Ingredients in Metal Diborides

“…In the past few years, non‐noble‐metal‐based electrocatalysts such as phosphides, sulfides, nitrides, carbides, and metal alloys were shown to have outstanding electrocatalytic performance. Among these materials, transition‐metal borides such as MoB (bulk), FeB 2 (nanoscale), Co‐B (amorphous), Co‐Ni‐B (amorphous), Ni‐B (amorphous), Mo 3 B (film), MoAlB (bulk), and VB 2 (nanoscale) have drawn considerable attention recently owing to their low cost, excellent electrocatalytic activity, and stability both in acidic and/or basic solutions. Among these borides, those containing the flat graphene‐like boron layer, such as α‐MoB 2 , FeB 2 , and VB 2 , have the highest HER activity.…”

“…Similar to β‐MoB 2 , Δ G H values for the puckered B and the W2 surfaces in β‐WB 2 are far below zero even at 100 % H‐coverage (light‐green and orange lines in Figure a), indicating weak HER activity of these two surfaces. At 25 % H‐coverage, Δ G H for the flat B surface in β‐WB 2 is −0.10 eV and reaches zero between 25 and 50 % H‐coverage (green line in Figure a), indicating that the flat B surface is very active for HER, as found for all flat B surfaces studied until now . In contrast to β‐MoB 2 , for which the Mo surface is not active, the W1 surface in β‐WB 2 has a relatively high HER activity with a Δ G H reaching −0.20 eV at 50 % H‐coverage and staying nearly constant up to 100 % H‐coverage (red line in Figure a).…”

Synthesis and Characterization of Single-Phase Metal Dodecaboride Solid Solutions: Zr1–xYxB12 and Zr1–xUxB12

“…The compositional breadth of metal borides has resulted in a remarkable range of crystal structures. 1,2 This structural diversity yields exciting optical, magnetic and electronic, [3][4][5][6][7] catalytic, 8,9 and mechanical properties. 1,[10][11][12] Metal boride structures range from metal rich subborides 13 (M4B) to mono-, 14,15 di- 16,17 and tetraborides, [18][19][20] to boron rich borides: dodecaborides 21 (MB12) and higher borides 22 (MB66), and β-rhombohedral boron doping phases 23,24 (MB50-100); as well as ternary and multinary metal borides.…”

The Holy Grail in Platinum‐Free Electrocatalytic Hydrogen Evolution: Molybdenum‐Based Catalysts and Recent Advances

“…Even though the catalytic activity of these above mentioned MoB x is already considerable, the irregular shape and large size of catalyst particles indeed limits their HER performances and their activity should therefore be further optimized by downsizing. Advances in the synthesis of nanoscale or controllably doped MoB x must unlock their great potentials for future HER catalysts …”