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β-Graphdiyne (β-GDY) is a member of 2D graphyne family with zero band gap, and is a promising material with potential applications in energy storage, organic electronics, etc. However, the synthesis of β-GDY has not been realized yet, and the measurement of its intrinsic properties remains elusive. In this work, β-GDY-containing thin film is successfully synthesized on copper foil using modified Glaser–Hay coupling reaction with tetraethynylethene as precursor. The as-grown carbon film has a smooth surface and is continuous and uniform. Electrical measurements reveal the conductivity of 3.47 × 10⁻⁶ S m⁻¹ and the work function of 5.22 eV. TiO₂@β-GDY nanocomposite is then prepared and presented with an enhancement of photocatalytic ability compared to pure TiO₂.

A modified Glaser–Hay coupling reaction is used to synthesize β-graphdiyne-containing thin film. Copper foil plays the role of both a substrate and the source of catalyst. The as-grown film is with conductivity property and can be applied to enhance the photocatalytic property of TiO₂.

The search for highly efficient and low-cost catalysts is one of the main driving forces in catalytic chemistry. Current strategies for the catalyst design focus on increasing the number and activity of local catalytic sites, such as the edge sites of molybdenum disulfides in the hydrogen evolution reaction (HER). Here, the study proposes and demonstrates a different principle that goes beyond local site optimization by utilizing topological electronic states to spur catalytic activity. For HER, excellent catalysts have been found among the transition-metal monopnictides—NbP, TaP, NbAs, and TaAs—which are recently discovered to be topological Weyl semimetals. Here the study shows that the combination of robust topological surface states and large room temperature carrier mobility, both of which originate from bulk Dirac bands of the Weyl semimetal, is a recipe for high activity HER catalysts. This approach has the potential to go beyond graphene based composite photocatalysts where graphene simply provides a high mobility medium without any active catalytic sites that have been found in these topological materials. Thus, the work provides a guiding principle for the discovery of novel catalysts from the emerging field of topological materials.

For the first time, Weyl semimetals are used as catalysts for highly effective hydrogen evolution reactions. The high mobility of carriers because of linear band crossings near the Fermi level is the major factor for their high activity. Unlike other catalysts, effect of the disorder at the surface is not a concern due to the topologically protected robust surface states.

A novel phase transition, from multilayered 2H-MoTe₂ to a parallel bundle of sub-nanometer-diameter metallic Mo₆Te₆ nanowires (NWs) driven by catalyzer-free thermal-activation (400–500 °C) under vacuum, is demonstrated. The NWs form along the 〈11–20〉 2H-MoTe₂ crystallographic directions with lengths in the micrometer range. The metallic NWs can act as an efficient hole injection layer on top of 2H-MoTe₂ due to favorable band-alignment. In particular, an atomically sharp MoTe₂/Mo₆Te₆ interface and van der Waals gap with the 2H layers are preserved. The work highlights an alternative pathway for forming a new transition metal dichalcogenide phase and will enable future exploration of its intrinsic transportation properties.

A novel phase transition, from multilayered 2H-MoTe₂ to a parallel bundle of metallic Mo₆Te₆ sub-nanometer-diameter nanowires, with lengths in the micrometer range driven by catalyzer-free thermal-activation (400–500 °C) under vacuum, is demonstrated. This work highlights an alternative pathway for forming a new transition metal dichalcogenide phase, and enables future exploration of its intrinsic transportation properties.

Ultrabroad-spectrum absorption and highly efficient generation of available charge carriers are two essential requirements for promising semiconductor-based photocatalysts, towards achieving the ultimate goal of solar-to-fuel conversion. Here, a fascinating nonmetal plasmonic Z-scheme photocatalyst with the W₁₈O₄₉/g-C₃N₄ heterostructure is reported, which can effectively harvest photon energies spanning from the UV to the nearinfrared region and simultaneously possesses improved charge-carrier dynamics to boost the generation of long-lived active electrons for the photocatalytic reduction of protons into H₂. By combining with theoretical simulations, a unique synergistic photocatalysis effect between the semiconductive Z-scheme charge-carrier separation and metal-like localized-surface-plasmon-resonance-induced “hot electrons” injection process is demonstrated within this binary heterostructure.

Almost a full-solar-spectrum-driven photocatalytic H₂ evolution is achieved over the nonmetal plasmonic Z-Scheme photocatalyst of the W₁₈O₄₉/g-C₃N₄ heterostructure based on the unique synergetic photocatalysis effect between semiconductive Z-scheme charge-carriers separation and metal-like localized-surface-plasmon-resonance.

In article number 1605607, Yan Yu, Liang Li, and co-workers present amorphous, hydrogenated, and selfordered nanoporous Nb₂O₅ films as excellent electrodes for sodium batteries, affording a sustainable capacity delivery and robust high-rate capability. This collaborative material engineering of structural order, composition, and architecture opens up new possibilities to developing more accessible, sustainable, and producible energy-storage solutions.

Mercury telluride (HgTe) colloidal quantum dots (CQDs) have been developed as promising materials for the short and mid-wave infrared photodetection applications because of their low cost, solution processing, and size tunable absorption in the short wave and mid-infrared spectrum. However, the low mobility and poor photogain have limited the responsivity of HgTe CQD-based photodetectors to only tens of mA W⁻¹. Here, HgTe CQDs are integrated on a TiO₂ encapsulated MoS₂ transistor channel to form hybrid phototransistors with high responsivity of ≈10⁶ A W⁻¹, the highest reported to date for HgTe QDs. By operating the phototransistor in the depletion regime enabled by the gate modulated current of MoS₂, the noise current is significantly suppressed, leading to an experimentally measured specific detectivity D* of ≈10¹² Jones at a wavelength of 2 µm. This work demonstrates for the first time the potential of the hybrid 2D/QD detector technology in reaching out to wavelengths beyond 2 µm with compelling sensitivity.

High-performance hybrid MoS₂/TiO₂/HgTe photodetectors with a responsivity of 10⁶ A W⁻¹, sensitivity of 10¹² Jones, temporal response of <4 ms, and spectral coverage beyond 2 µm, which benefit from the long wavelength light absorption of HgTe quantum dots, huge photogain mechanism, and low noise current, can provide a new platform for mid and long-wave infrared photodetector applications.

Irradiation of 2D sheets of transition metal dichalcogenides with ion beams has emerged as an effective approach to engineer chemically active defects in 2D materials. In this context, argon-ion bombardment has been utilized to introduce sulfur vacancies in monolayer molybdenum disulfide (MoS₂). However, a detailed understanding of the effects of generated defects on the functional properties of 2D MoS₂ is still lacking. In this work, the correlation between critical electronic device parameters and the density of sulfur vacancies is systematically investigated through the fabrication and characterization of back-gated monolayer MoS₂ field-effect transistors (FETs) exposed to a variable fluence of low-energy argon ions. The electrical properties of pristine and ion-irradiated FETs can be largely improved/recovered by exposing the devices to vapors of short linear thiolated molecules. Such a solvent-free chemical treatment—carried out strictly under inert atmosphere—rules out secondary healing effects induced by oxygen or oxygen-containing molecules. The results provide a guideline to design monolayer MoS₂ optoelectronic devices with a controlled density of sulfur vacancies, which can be further exploited to introduce ad hoc molecular functionalities by means of thiol chemistry approaches.

Ion irradiation is used to controllably introduce sulfur vacancies in monolayer MoS₂ sheets, which serve as channel material in field-effect transistors. The evolution of critical device parameters is systematically investigated as a function of sulfur-vacancy density. A vapor-phase treatment, based on short linear thiolated molecules, enables a remarkable recovery of the functional properties of defective 2D MoS₂.

Graphene has initiated intensive research efforts on 2D crystalline materials due to its extraordinary set of properties and the resulting host of possible applications. Here the authors report on the controllable large-scale synthesis of C₃N, a 2D crystalline, hole-free extension of graphene, its structural characterization, and some of its unique properties. C₃N is fabricated by polymerization of 2,3-diaminophenazine. It consists of a 2D honeycomb lattice with a homogeneous distribution of nitrogen atoms, where both N and C atoms show a D_6h-symmetry. C₃N is a semiconductor with an indirect bandgap of 0.39 eV that can be tuned to cover the entire visible range by fabrication of quantum dots with different diameters. Back-gated field-effect transistors made of single-layer C₃N display an on–off current ratio reaching 5.5 × 10¹⁰. Surprisingly, C₃N exhibits a ferromagnetic order at low temperatures (<96 K) when doped with hydrogen. This new member of the graphene family opens the door for both fundamental basic research and possible future applications.

C₃N consists of a 2D honeycomb lattice with a homogeneous distribution of nitrogen atoms, where both N and C atoms show D_6h-symmetry. It is a semiconductor with an indirect bandgap of 0.39 eV. Back-gated field-effect transistors made of single-layer C₃N display an on–off current ratio reaching 5.5 × 10¹⁰. Surprisingly, C₃N exhibits ferromagnetic order when doped with hydrogen.

In this work, the mixed bromide iodide lead perovskites CH3NH3Pb(I1– xBrx)3 (0 ≤ x ≤ 0.67) thin films were prepared by co-evaporation of CH3NH3I, PbI2, and PbBr2. The electronic properties of CH3NH3Pb(I1– xBrx)3 thin films were investigated by X-ray and ultraviolet photoelectron spectroscopy in-situ. The results of core level binding energy show that there is no chemical shift of the C1s, N1s, Br3d5, and I3d5 when the Br composition changes, while there is an approximately linear chemical shift of Pb4f7 to higher binding energy as the Br composition increases. The density functional theory calculation reveals that there is more charge transfer from Pb to Br than I, which results in the chemical shift of Pb4f states. On the other hand, the valence band maximum increases as the Br composition increases, while the work function shows no obvious change, because the conduction band is dominated by Pb 6p orbitals while the valence band is dominated by halide p orbitals. Our work demonstrates the adjustability of the energy level alignment of MAPb(I1– xBrx)3 by the Br composition.