Among van der Waals (vdW) layered ferromagnets, Fe 3 GeTe 2 (FGT) is an excellent candidate material to form FGT/heavy metal heterostructures for studying the effect of spin-orbit torques (SOT). Its metallicity, strong perpendicular magnetic anisotropy built in the single atomic layers, relatively high Curie temperature (T c ~ 225 K) and electrostatic gate tunability offer a tantalizing possibility of achieving the ultimate high SOT limit in monolayer all-vdW nanodevices. In this study, we fabricate heterostructures of FGT/Pt with 5 nm of Pt sputtered onto the atomically flat surface of ~ 15 -23 nm exfoliated FGT flakes. The spin current generated in Pt exerts a damping-like SOT on FGT magnetization. At ~2.5x10 11 A/m 2 current density, SOT causes the FGT magnetization to switch, which is detected by the anomalous Hall effect of FGT. To quantify the SOT effect, we measure the second harmonic Hall responses as the applied magnetic field rotates the FGT magnetization in the plane. Our analysis shows that the SOT efficiency is comparable with that of the best heterostructures containing three-dimensional (3D) ferromagnetic metals and much larger than that of heterostructures containing 3D ferrimagnetic insulators. Such large efficiency is attributed to the atomically flat FGT/Pt interface, which demonstrates the great potential of exploiting vdW heterostructures for highly efficient spintronic nanodevices.

Non-noble metal nanomaterials (molybdenum sulfides, phosphides, carbides, and nitrides) have recently emerged as highly active electrocatalysts for the hydrogen evolution reaction (HER). Here we present experimental and theoretical studies of the first highly active molybdenum boride nanomaterial for the HER.

Two different boron layers, flat (graphene-like) and puckered (phosphorene-like), found in the crystal structure of MoB show drastically different activities for hydrogen evolution, according to Gibbs free energy calculations of H-adsorption on MoB. The graphene-like B layer is highly active, whereas the phosphorene-like B layer performs very poorly for hydrogen evolution. A new Sn-flux synthesis permits the rapid single-phase synthesis of MoB, and electrochemical analyses show that it is one of the best hydrogen evolution reaction active bulk materials with good long-term cycle stability under acidic conditions. MoB compensates its smaller density of active sites if compared with highly active bulk MoB (which contains only the more active graphene-like boron layers) by a 5-times increase of its surface area.

Most nanomaterials, such as transition metal carbides, phosphides, nitrides, chalcogenides, etc., have been extensively studied for their various properties in recent years. The similarly attractive transition metal borides, on the contrary, have seen little interest from the materials science community, mainly because nanomaterials are notoriously difficult to synthesize. Herein, a simple, general synthetic method toward crystalline transition metal boride nanomaterials is proposed. This new method takes advantage of the redox chemistry of Sn/SnCl , the volatility and recrystallization of SnCl at the synthesis conditions, as well as the immiscibility of tin with boron, to produce crystalline phases of 3d, 4d, and 5d transition metal nanoborides with different morphologies (nanorods, nanosheets, nanoprisms, nanoplates, nanoparticles, etc.). Importantly, this method allows flexibility in the choice of the transition metal, as well as the ability to target several compositions within the same binary phase diagram (e.g., Mo B, α-MoB, MoB , Mo B ). The simplicity and wide applicability of the method should enable the fulfillment of the great potential of this understudied class of materials, which show a variety of excellent chemical, electrochemical, and physical properties at the microscale.

We report the synthesis of electrode materials based on onedimensional α-NiMoO 4 nanorods for application as a supercapacitor. The structure and morphology of the electrodes were characterized by powder X-ray diffraction, Raman analysis, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. The maximum specific capacitance obtained from electrochemical measurements on a standard three-electrode system was 730 F g -1 at a scan rate of 5 mV s -1 . Furthermore, an asymmetric supercapacitor [a] World Premier International (WPI)

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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.

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