Cu-doped Ag2BiI5 (Cu:SBI) powders with 0–10 mol% doping concentrations were synthesized by a solid-state method in an evacuated glass tube. While doping of Cu did not appreciably modify the crystallographic...

A hierarchical electrode consisting of edge-exposed 1T phase WS2, grown on an array of surface-modified WO3 nanohelixes (NHs), and its enhanced catalytic performance in the hydrogen evolution reaction (HER) are presented.

Metal to semiconductor transition by hole compensation of excess electrons from VO and localized VO state in La0.5Sr0.5FeO3−δ under low PO2.

Although smart windows have received wide attention as energy-saving devices, conventional metal-to-insulator materials such as VO2 hinder their commercial usage because of their high transition temperature and low solar energy modulation. Further development can be achieved by finding a new material system that can effectively overcome these limitations. In this study, first-principles density functional theory calculations are used to investigate the possibility of exploiting a spin-polarized band gap material for smart window applications. Halide cuprite perovskites (A2CuX4) were chosen because they have a spin-polarized band gap that can be tuned by element selection at sites A and X. Our study shows that the optical transmittance of the insulating phase is increased by a violation of the selection rule. The spin-polarized band gap is closely related to the metal-to-insulator transition temperature and can be modulated by chemical engineering, strain engineering, or both. Therefore, A2CuX4 is a promising candidate for smart windows.

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Functional h-BN (hexagonal boron nitride) has been prepared via the incorporation of transition metal (TM) impurities like nanoparticles and single atoms. Herein, scanning transmission electron microscopy (STEM) combined with density functional theory (DFT) was employed to study Ta-, Co-, Ni-, and Ir-decorated h-BN monolayers to provide an overview of their preferential site occupancies and morphological evolutions on h-BN. Ta, Ni, Ir, and Co single atoms are all positioned on the nitrogen of h-BN; however DFT predicts the occupancy site can vary with their spin state. In terms of microstructural evolution, Co, Ni, and Ir atoms form 3D nanoclusters while Ta atoms are well dispersed and thus the single Ta atom can be decorated on h-BN. This study highlights on TM/h-BN interaction dynamics and presents an avenue for designing nanostructures for electrocatalytic application.

We successfully accomplished the conformal growth of sp2-hybridized few-layer h-BN over an array of Si-based nanotrenches with a 45 nm pitch and an aspect ratio of ∼7:1 by using the pulsed-mode metal–organic chemical vapor deposition (MOCVD) method. Surface-sensitive X-ray absorption fine structure spectroscopy and density functional theory calculations revealed that the B–O bonds formed on the noncatalytic SiO2 surface act as nucleation sites for the subsequential formation of mixed sp2- and sp3-hybridized BON2 and BN3 at the very initial stage of the pulsed-mode injection of MOCVD precursors, enabling the conformal growth of few-layer sp2-hybridized h-BN with an excellent step coverage. We believe that these results can provide a broad avenue for the implementation of fascinating two-dimensional layered materials for current state-of-the-art three-dimensional Si-based nanoscale architectures, overcoming the downscaling limits.

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