Ultrahigh energy storage density of 52.4 J cm with optimistic efficiency of 72.3% is achieved by interface engineering of epitaxial lead-free oxide multilayers at room temperature. Moreover, the excellent thermal stability of the performances provides solid basis for widespread applications of the thin film systems in modern electronic and power modules in harsh working environments.

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This paper describes the synthesis of TiO₂ branched nanorod arrays (TiO₂ BNRs) with plasmonic Au nanoparticles attached on the surface. Such Au/TiO₂ BNR composites exhibit high photocatalytic activity in photoelectrochemical (PEC) water splitting. The unique structure of Au/TiO₂ BNRs shows enhanced activity with a photocurrent of 0.125 mA cm(-2) under visible light (≥420 nm) and 2.32 ± 0.1 mA cm(-2) under AM 1.5 G illumination (100 mW cm(-2)). The obtained photocurrent is comparable to the highest value ever reported. Furthermore, the Au/TiO₂ BNRs achieve the highest efficiency of ∼1.27% at a low bias of 0.50 V vs. RHE, indicating elevated charge separation and transportation efficiencies. The high PEC performance is mainly due to the plasmonic effect of Au nanoparticles, which enhances the visible light absorption, together with the large surface area, efficient charge separation and high carrier mobility of the TiO₂ BNRs. The carrier density of Au/TiO₂ BNRs is nearly 6 times higher than the pristine TiO₂ BNRs as calculated by the Mott-Schottky plot. Based on the analysis by UV-Vis spectroscopy, electrochemical impedance spectroscopy, and photoluminescence, a mechanism was proposed to explain the high activity of Au/TiO₂ BNRs in PEC water splitting. The capability of synthesizing highly visible light active Au/TiO₂ BNR based photocatalysts is useful for solar conversion applications, such as PEC water splitting, dye-sensitized solar cells and photovoltaic devices.

An efficient homotype Ag3PO4/BiVO4 heterojunction photocatalyst is described. Ag3PO4 nanoparticles preferentially deposit on the highly active BiVO4(040) facets by means of heterojunction construction together with morphology engineering. The Ag3PO4/BiVO4 photocatalyst shows high charge separation efficiency as well as enhanced visible‐light response ability and thus possesses superior visible light photocatalytic activity.

Abstract2D magnetic materials have aroused widespread research interest owing to their promising application in spintronic devices. However, exploring new kinds of 2D magnetic materials with better stability and realizing their batch synthesis remain challenging. Herein, the synthesis of air‐stable 2D Cr5Te8 ultrathin crystals with tunable thickness via tube‐in‐tube chemical vapor deposition (CVD) growth technology is reported. The importance of tube‐in‐tube CVD growth, which can significantly suppress the equilibrium shift to the decomposition direction and facilitate that to the synthesis reaction direction, for the synthesis of high‐quality Cr5Te8 with accurate composition, is highlighted. By precisely adjusting the growth temperature, the thickness of Cr5Te8 nanosheets is tuned from ≈1.2 nm to tens of nanometers, with the morphology changing from triangles to hexagons. Furthermore, magneto‐optical Kerr effect measurements reveal that the Cr5Te8 nanosheet is ferromagnetic with strong out‐of‐plane spin polarization. The Curie temperature exhibits a monotonic increase from 100 to 160 K as the Cr5Te8 thickness increases from 10 to 30 nm and no apparent variation in surface roughness or magnetic properties after months of exposure to air. This study provides a robust method for the controllable synthesis of high‐quality 2D ferromagnetic materials, which will facilitate research progress in spintronics.

SignificanceFerromagnetic insulators are highly needed as the necessary components in developing next-generation dissipationless quantum-spintronic devices. Such materials are rare, and those high symmetric ones without chemical doping available so far only work below 16 K. Here we demonstrate a tensile-strained LaCoO3 film to be a strain-induced high-temperature ferromagnetic insulator. Both experiments and first-principles calculations demonstrated that the tensile-strain–supported ferromagnetism reaches its strongest when the composition is nearly stoichiometric. It disappears when the Co2+ defect concentration reaches around 10%. The discovery represents a chance for the availability of such materials, a high operation temperature, and a high epitaxial integration potential for making future devices.

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This paper describes the design, characterization, and utilization of branched TiO2 nanoarrays sensitized with CdS quantum dots as anodes for photoelectrochemical water splitting. The remarkable photocurrent density (∼4 mA cm(-2) at a potential of 0 V versus Ag/AgCl) and high solar to hydrogen efficiency of the materials obtained were ascribed to the novel branched nanostructure and efficient electron transfer from CdS to TiO2.