A novel flexible electrode with a sandwich structure consisting of double stabilizing buffer layers is designed and fabricated for the first time, and significant improvement in cycling stability and desired areal capacity is achieved. This strategy will allow large volume change metal oxide electrodes to be applied in energy storage and related fields.
Photocatalytic hydrogen evolution from pure water and bifunctional photocatalytic reaction are realized using a CoP/CdS/WS2 photocatalyst, which has a p–n–n tandem heterostructure.
Abstract Binary metal oxides (such as NiCo 2 O 4 ) are regarded as attractive electrode materials for advanced energy storage devices since they offer more electrochemical activity and higher capacity than monometal oxide. However, the volume expansion and low electronic conductivity are the main bottleneck seriously hindering their application. To overcome these barriers, a novel strategy that introduces a bimetallic oxynitride layer (NiCoON) with oxygen vacancy to the surface of NiCo 2 O 4 nanowires as an anode for Li‐ion capacitors (LICs) is proposed. The oxygen vacancy on the surface and the modulation of multiple valence states are investigated by the electron paramagnetic resonance, X‐ray photoelectron spectroscopy characterization, and first‐principles calculation. Benefiting from the merits of substantially improved electrical conductivity and increased concentration of active sites, the optimized NiCoON electrode delivers remarkable capacity (1855 mAh g −1 at 0.2 A g −1 ) and rate performance. The LIC device assembled by NiCoON anodes and N‐doped carbon nanowire cathodes delivers excellent rate capability, high energy density (148.5 Wh kg −1 ), and outstanding power density (30 kW kg −1 ). This study provides a new pathway for developing bimetallic oxides with an improved performance in electrochemical energy storage, conversion fields, and beyond.
In this study, boron carbon nitride (BCN) nanosheets were used as a substrate coating material to grow gallium nitride (GaN) crystals by hydride vapor phase epitaxy.
We herein report a simple and effective method to fabricate superhydrophobic coatings by grafting polystyrene (PS) onto the vinyltriethoxysilane modified hollow silica nanoparticles (HSNs) using free radical polymerization. The resulting products were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM) and transmission electron microscopy, confirming that the PS successfully grafted onto the vinyl-modified HSNs via a covalent bond. The morphological structure of HSN film, investigated by SEM, showed a characteristic rough structure. Surface wetting properties of the HSN films were evaluated by measuring the water contact angle and the sliding angle using a contact angle goniometer, which were measured to be 158° and 6°, respectively. Moreover, the classic and the modified Cassie–Baxter relations were applied on the HSN films to verify the superhydrophobic performance.
A simple and effective method is presented to fabricate surface-roughened InGaN/GaN-based light emitting diodes (LEDs) epistructure using annealing-formed, random-distributed Au particle arrays as dry etching mask. The shapes of GaN nanoislands, with horizontal diameters of 100–500 nm and vertical depths up to 140 nm, are determined by Au mask particles. Importantly, this roughened surface exhibits strong photoluminescence (PL) light-output enhancement by a factor of more than 1.6 orders of magnitude. This method will put forward new promising applications in the electroluminescent devices, especially in solid state lighting.
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