van der Waals (vdW) metal chalcogenides have been extensively investigated as electrocatalysts for the hydrogen evolution reaction (HER); however, for the majority of these materials only the edges are active, thereby wasting most of the materials' surfaces. Recent research has focused on finding new materials with active basal planes. Herein, for the first time, we demonstrate that the hexagonal vdW Fe 3 GeTe 2 (FGT), also a spintronic candidate material, shows both basal plane and edge site HER activities. Partial exfoliation of bulk FGT through sonication increases both basal plane and edge sites leading to significantly improved overpotential. A subsequent compacting of the sample (using plasma sintering at room temperature) to produce a densified electrode leads to an impressive overpotential to drive a current density of 10 mA/cm 2 of −0.105 V. DFT free energy calculations not only showed that the high activity is due to the abundant active sites present on the hexagonal Te layer in FGT but also presented an even more HER active layer (106) containing both iron and tellurium active sites. Furthermore, the presence of a thin oxide layer on top of the active FGT layers, as found by XPS, suggests that the real active surface is likely a hybrid FGT/oxide layer. These results demonstrate the high basal plane and edge sites HER activity of FGT, thus opening a new avenue for the design and screening of related iron-based vdW materials, their composites, and their surface functionalization as high-performing electrocatalysts.

Whilst MXenes (2D carbides and nitrides) have become highly popular in several research fields including the hydrogen evolution reaction (HER), unfortunately they are not competitive HER electrocatalysts in their bulk form (MAX phases). The related MAB (2D-like bulk borides) phases and the derived 2D MBenes, however, are less studied but show better HER properties. Herein, two highly HER-active and abundant MAB phases, Ni nþ1 ZnB n (n ¼ 1, 2), are studied experimentally and computationally. The pressed pellet electrodes from bulk polycrystalline powders of these phases drive a current density of 10 mA cm À2 at impressive overpotentials of η 10 ¼ À0.171 V (n ¼ 1) and η 10 ¼ À0.145 V (n ¼ 2) to efficiently produce hydrogen. Density functional theory (DFT) calculations prove that the most active site is the hollow site on the nickel basal plane, showing a free energy value comparable to that of the hollow site of Pt (111). This study paves the way for further development of bulk and nanoscale MAB phases for clean energy applications.

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Recent research on van der Waals (vdW) metal chalcogenides electrocatalysts for the hydrogen evolution reaction (HER) has been devoted to finding new catalysts with active basal planes. Here, we report on experimental and theoretical investigations of the HER activity of a recently discovered iron‐rich vdW spintronic material, Fe5Ge2Te2 (FG2T) in alkaline media (1 M KOH). We show that a densified electrode of FG2T requires an overpotential of only −90.5 mV to drive a current density of 10 mA/cm2. Free energy calculations of hydrogen adsorption using density functional theory (DFT) proved that the numerous sites present on the hexagonal Te layer are more active than those found in the recently proposed Fe3GeTe2 (FGT) catalyst, supporting higher activity for the new Fe‐richer catalyst. Like in FGT, XPS analysis has found that a thin oxide layer covers the active FG2T layers, suggesting the real active surface to be a hybrid FG2T/oxide layer. These results strengthen the idea of continued screening of iron‐based vdW materials to replace the non‐abundant platinum group electrocatalysts toward HER and other electrocatalytic processes.