MBenes hold many merits for electrocatalysis of the nitrogen reduction reaction, including outstanding stability in aqueous environments, excellent electrical conductivity, an inhibited hydrogen evolution reaction, and highly active boron and metal surfaces.

Inspired by the synthesis of Janus MoSSe and its beneficial properties, we here report for the first time the adsorption and diffusion of Li-ion on the single-layer MoSSe (SLM) and the double-layer MoSSe (DLM) using first-principle computations. The results show that much more Li-ions can be stored by the SLM and DLM due to their intrinsic dipole moment and the charge redistribution. With a suitable open circuit voltage range vs Li+/Li, the ideal theoretical capacities for the SLM and DLM are 776.5 and 452.9 mAh/g, respectively. Furthermore, the calculated density of states of the lithiated SLM and DLM indicates that they have good electrical conduction, and the smaller Li-ion/Li-vacancy migration barrier ensures fast Li-ion diffusion. Our results suggest that the SLM and DLM can be utilized as a potential anode material for high-performance Li-ion batteries.

From first principles calculations, the lowest energy structures of bilayer MoSSe with different combination patterns (S-S, Se-Se, and S-Se bilayers) have been confirmed. The results demonstrate that the band gap of bilayer MoSSe can be tuned by interlayer distance and dipole moment. A larger interlayer distance increases the band gap, while a larger dipole moment reduces the band gap. That is, the gap is affected by the synergistic effects of dipole moment and interlayer distance in a MoSSe bilayer. Our results provide a new way to realize band gap modulation by changing the dipole moment or the interlayer distance. Impressively, another important finding is that the S-Se bilayer has a type-II band alignment, which makes it a good candidate for applications in optoelectronics.

As analogues of two-dimensional (2D) layered materials, searching for one-dimensional (1D) van der Waals wired materials as 1D Lego blocks for integration and device applications has been pursued. Motivated by the recently synthesized atomic wires of molybdenum chalcogenide, here we explored the structures and stability of 66 atomic wires of 3d, 4d, and 5d transition metal chalcogenides in the M 6 X 6 stoichiometry (M = transition metal, X = chalcogen). After high-throughput first-principles calculations, 53 unprecedented and experimentally feasible M 6 X 6 wires have been identified. Diverse functionalities are found in these 1D materials, including semiconductors, metals, and ferromagnets with high Young’s modulus and large fracture strain. Notably, six kinds of M 6 X 6 wires are robust ferromagnets with Curie temperatures up to 700 K, which can be further elevated under axial strains. Moreover, these M 6 X 6 atomic wires possess high stability and resistance to oxidation, humidity, and aggregation; both merits are desirable for device applications. This large family of 1D materials with definite structures and rich properties allows atomically precise integration for flexible electronics and spintronics.

Low-dimensional materials with definite geometrical and electronic structures have long been pursued to fulfill the requirement of technological devices toward miniaturization, multifunctionality, and precise manufacturing. Inspired by the emerging transition metal halide monolayers with intriguing magnetic behavior, here we systematically explore stable one-dimensional (1D) structures of transition metal halides. By first-principles calculations, a total of 208 TMX2 and TMX3 (TM is 3d, 4d, 5d transition metal elements; X = F, Cl, Br, I) nanowires have been predicted, showing diverse electronic and magnetic properties, such as ferromagnetic semiconductors, half metals, and antiferromagnets. They possess many application-desired characters, including a wide range of bandgaps, small carrier effective masses, outstanding capability for solar energy harvesting, and strong ferromagnetic or antiferromagnetic order. This large family of TMXn nanowires provides a great platform for exploring exotic 1D physics as well as for designing high-performance devices.