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Graphene/hexagonal boron nitride (h‐BN) monolayer in‐plane heterostructure offers a novel material platform for both fundamental research and device applications. To obtain such a heterostructure in high quality via controllable synthetic approaches is still challenging. In this work, in‐plane epitaxy of graphene/h‐BN heterostructure is demonstrated on Cu–Ni substrates. The introduction of nickel to copper substrate not only enhances the capability of decomposing polyaminoborane residues but also promotes graphene growth via isothermal segregation. On the alloy surface partially covered by h‐BN, graphene is found to nucleate at the corners of the as‐formed h‐BN grains, and the high growth rate for graphene minimizes the damage of graphene‐growth process on h‐BN lattice. As a result, high‐quality graphene/h‐BN in‐plane heterostructure with epitaxial relationship can be formed, which is supported by extensive characterizations. Photodetector device applications are demonstrated based on the in‐plane heterostructure. The success will have important impact on future research and applications based on this unique material platform. [ABSTRACT FROM AUTHOR]

Molybdenum carbide–graphene hybrid constituting few‐layer graphene and molybdenum carbide nanoparticles is synthesized by carburizing molybdenum disulfide atomic layer substrate. At the elevated temperature and reducing environment, molybdenum disulfide is reduced to molybdenum acting as the catalyst for graphene growth, while simultaneously molybdenum atoms are carburized to form molybdenum carbide. This hybrid has potential applications in heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) layered semiconducting transition-metal dichalcogenides (TMDCs) are promising candidates for next-generation ultrathin, flexible, and transparent electronics. Chemical vapor deposition (CVD) is a promising method for their controllable, scalable synthesis but the growth mechanism is poorly understood. Herein, we present systematic studies to understand the CVD growth mechanism of monolayer MoSe2, showing reaction pathways for growth from solid and vapor precursors. Examination of metastable nanoparticles deposited on the substrate during growth shows intermediate growth stages and conversion of non-stoichiometric nanoparticles into stoichiometric 2D MoSe2 monolayers. The growth steps involve the evaporation and reduction of MoO3 solid precursors to sub-oxides and stepwise reactions with Se vapor to finally form MoSe2. The experimental results and proposed model were corroborated by ab initio Car-Parrinello molecular dynamics studies. [ABSTRACT FROM AUTHOR]

Although a lot of work has been reported on the growth and properties of 2D atomic layered materials, the growth mechanism for these crystals via the chemical vapor deposition method (CVD) has remained elusive. Here, a screw dislocation-driven spiral growth of SnSe2 crystal flakes via CVD is reported. The polymorph of as-synthesized SnSe2 crystals is verified as 1T-phase by both experimental characterization and theoretical calculation. The density functional theory study reveals morphology transformation during the growth process while phase-field modeling unravels the screw dislocation propagation to form the pyramid-like structure of SnSe2. The optical band gap of SnSe2 crystals relates to an indirect band gap of 1.0 eV. The photodetector devices based on SnSe2 crystals exhibit high responsivity and ultrafast response time in the microsecond regime. [ABSTRACT FROM AUTHOR]

Abstract: A chemical vapor infiltration (CVI) technique was used to overcome most of the challenges involved in fabricating exceptionally-tough CNT/SiC composites. Nanotube pullout and sequential breaking and slippage of the walls of the CNTs during failure were consistently observed for all fractured CNT/SiC samples. These energy absorbing mechanisms result in the fracture strength of the CNT/SiC composites about an order of magnitude higher than the bulk SiC. The CVI-fabricated CNT/SiC composites have an strongly-bonded tube/matrix interface and an amorphous, crack-free SiC matrix, enabling the composites to withstand oxidization at 700–1600°C in air. [Copyright &y& Elsevier]

Protonic ceramic electrochemical cells (PCECs) have the potential in reducing the energy input and carbon emissions in ethylene production from ethane dehydrogenation. The performance of conventional perovskite-based anode materials for ethane conversion in PCECs is limited by their low active surface area and proneness to coke deposition. In this work, for the first time, we demonstrate the use of aligned carbon nanotube forests (CNTFs) as a novel anode material for an ethane fueled PCEC to co-produce ethylene and electricity. The CNTF electrode was grown on the electrolyte by the chemical vapor deposition (CVD) method. Highly dispersed iron carbide nanoparticles are formed in situ on the CNTFs during the CVD process, acting as highly active catalysts for ethane dehydrogenation. The novel PCECs show superior catalytic and electrochemical performances to that using conventional perovskite-based anodes. The cell also exhibits excellent durability and anti-coking abilities within 100 h test. This work showcases the promising application of nanostructured carbon, a new class of non-perovskite materials, as the multifunctional electrode materials for PCECs. [Display omitted] • CNTF can be integrated into PCEC as electrode and catalyst support by CVD method. • CNTF is a promising non-perovskite candidate electrode material for PCEC. • CNTF shows superior electrochemical and catalytic performance than SFM. • Carburized Fe species on CNTF are the active species for EDH reaction. [ABSTRACT FROM AUTHOR]

• Amorphous two-dimensional silica has been successfully fabricated. • Salt is a crucial for promoting the evaporation of transition metals (TMs). • TMs account for the hexagonal structure of 2D silica. • The group VB TMs facilitate the formation of uniform hexagonal 2D silica. Owing to their remarkable electronic properties, silica ultrathin films have been utilized as an insulating layer in nanoelectronics systems. Silica films have been epitaxially grown on different substrates using various synthesis methods. Among all fabrication approaches, chemical vapor deposition has long been an advanced method for synthesizing two-dimensional (2D) materials due to its ability to ensure precise stacking control and minimize contamination between layers. This study harnessed the potential of CVD to atomically fabricate thin layered 2D silica on a SiO 2 /Si substrate. Significantly, a unique combination of multiple transition metals and salt as the catalysts aided the formation of 2D silica for the first time. Salt is a crucial catalyst in promoting the evaporation of high-melting-point metal catalysts, resulting in hexagonal nucleation sites on the SiO 2 /Si wafer. By meticulously controlling growth parameters, a distinctive hexagonal structure was obtained. Correspondingly, this work delves into the growth mechanism of 2D silica, as evidenced by experiments involving salt alone and individual transition metals. Group VB transition metals played a prominent role in achieving the hexagonal structure compared to their group IVB counterparts. This research offers insight into the formation and growth mechanism of 2D silica, expanding the understanding of silica nanostructures. [ABSTRACT FROM AUTHOR]