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2D layered transition metal dichalcogenides (TMDCs) have emerged as new possibilites beyond conventional particulate catalysts in facilitating efficient electrochemical hydrogen evolution. This is mainly mediated by the ultrahigh surface-to-volume ratio and the effective coupling of all active sites with supporting electrodes. Especially, the facile chemical vapor deposition (CVD) method has enabled morphological engineering of monolayer TMDC catalysts toward development of abundant active edge sites within the 2D plane. Here, two pathways to achieve such purpose are highlighted, either by non-equilibrium growth of MoS₂ dendrites or throughout high-density nucleation of MoS₂ nanoflakes directly on the electrode materials. Furthermore, future research directions have also been proposed and discussed to further enhance the efficiency of such unique catalysts.

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) represent an emerging form of catalysts in facilitating efficient electrochemical hydrogen evolution. The facile chemical vapor deposition (CVD) method enables morphological engineering of monolayer TMDC catalysts toward developing abundant active edge sites within the 2D plane. Recent advances concerning CVD-grown TMDC electrocatalysts are highlighted here.

Wet chemical synthesis of covalent III-V colloidal quantum dots (CQDs) has been challenging because of uncontrolled surfaces and a poor understanding of surface–ligand interactions. We report a simple acid-free approach to synthesize highly crystalline indium phosphide CQDs in the unique tetrahedral shape by using tris(dimethylamino) phosphine and indium trichloride as the phosphorus and indium precursors, dissolved in oleylamine. Our chemical analyses indicate that both the oleylamine and chloride ligands participate in the stabilization of tetrahedral-shaped InP CQDs covered with cation-rich (111) facets. Based on density functional theory calculations, we propose that fractional dangling electrons of the In-rich (111) surface could be completely passivated by three halide and one primary amine ligands per the (2×2) surface unit, satisfying the 8-electron rule. This halide–amine co-passivation strategy will benefit the synthesis of stable III-V CQDs with controlled surfaces.

InP colloidal tetrahedral nanocrystals were synthesized through a simple acid-free approach using tris(dimethylamino) phosphine and indium trichloride dissolved in oleylamine. Their formation was attributed to the unique stabilization of the In-rich (111) facets by co-passivation with halide and primary amine.

Self-assembly processes are very important in material sciences but are particularly difficult to predict quantitatively. This is the case for particulate magnetic materials in which field-induced self-assembly processes are essential. This article describes the recent advances in the development of predictive theoretical tools for the study of directed self-assembly of superparamagnetic colloids under magnetic fields. A practical view is presented of how to employ the new concepts (derived from thermodynamic theory) to predict the possible assembled structures from the properties of the colloids and thermodynamic conditions. Quantitative prediction of kinetics is also discussed for the cases in which equilibrium theory is not relevant. Finally, an outline of fundamental aspects of the theory is presented.

Recent theoretical advances allow quantitative predictions of self-assembly of superparamagnetic colloids under magnetic fields. This article describes how to employ self-assembly thermodynamics to predict the possible assembled structures from the properties of the colloidal suspension (particle, size, magnetization, concentration, temperature). Quantitative prediction of kinetics is also discussed for the cases in which equilibrium theory is not relevant.

Layered elemental materials, such as black phosphorus, exhibit unique properties originating from their highly anisotropic layered structure. The results presented herein demonstrate an anomalous anisotropy for the electrical, magnetic, and electrochemical properties of black phosphorus. It is shown that heterogeneous electron transfer from black phosphorus to outer- and inner-sphere molecular probes is highly anisotropic. The electron-transfer rates differ at the basal and edge planes. These unusual properties were interpreted by means of calculations, manifesting the metallic character of the edge planes as compared to the semiconducting properties of the basal plane. This indicates that black phosphorus belongs to a group of materials known as topological insulators. Consequently, these effects render the magnetic properties highly anisotropic, as both diamagnetic and paramagnetic behavior can be observed depending on the orientation in the magnetic field.

A shift in direction: The electrical, magnetic, and electrochemical properties of black phosphorus display an anomalous anisotropy. These unusual observations were interpreted by means of calculations, which manifested the metallic character of the edge plane and the semiconductivity of the basal plane, indicating that black phosphorus belongs to a group of materials known as topological insulators.

A novel ternary artificial nacre is developed through a vacuum-assisted filtration method, with reinforced ultrathin amorphous alumina that is grown in situ on the surface of GO. This ternary artificial nacre simultaneously shows exceptional strength and toughness, which have, up to now, been considered to be mutually exclusive. This novel material will play a role in the structuring of future materials.

Sulfur vacancies are demonstrated to modulate the interlayer interaction and bandgap in ReS₂ nanosheet transistors, influencing the current on/off ratio and mobility.

Large-area and highly crystalline CVD-grown multilayer MoSe₂ films exhibit a well-defined crystal structure (2H phase) and large grains reaching several hundred micrometers. Multilayer MoSe₂ transistors exhibit high mobility up to 121 cm² V⁻¹ s⁻¹ and excellent mechanical stability. These results suggest that high mobility materials will be indispensable for various future applications such as high-resolution displays and human-centric soft electronics.

Inorganic nanowire arrays hold great promise for next-generation energy storage and conversion devices. Understanding the growth mechanism of nanowire arrays is of considerable interest for expanding the range of applications. Herein, we report the solution-liquid-solid (SLS) synthesis of hexagonal nickel selenide nanowires by using a nonmetal molecular crystal (selenium) as catalyst, which successfully brings SLS into the realm of conventional low-temperature solution synthesis. As a proof-of-concept application, the NiSe nanowire array was used as a catalyst for electrochemical water oxidation. This approach offers a new possibility to design arrays of inorganic nanowires.

Crystal engineering: Solution-liquid-solid (SLS) synthesis has been brought into the realm of conventional low-temperature solution synthesis through the use of a nonmetal molecular crystal as a catalyst. This approach has been demonstrated by using selenium as the catalyst for the synthesis of hexagonal nickel selenide nanowire arrays, which were used for electrochemical water oxidation.