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Perovskite nanomaterials with highly stable and bright emission were requested for white light emitting diodes (LEDs). In this paper, superior thin CsPbBr 3 nanoplates (NPLs) with an average thickness of 1.9 nm were synthesized via solvothermal reactions. A bright blue-emitting peak at 455 nm with a photoluminescence (PL) quantum yield of 89 % was observed. The high PL efficiency was kept after storing for 90 days at ambient condition. This supplied an efficient approach to solve the problem of low PL efficiency and poor stability of blue-emitting perovskite nanocrystals. The thickness of CsPbBr 3 NPLs was adjusted by changing preparation conditions. The PL peak wavelength of CsPbBr 3 NPLs was adjusted in a region of 455–465 nm. Through dynamic anion exchange promoted cation exchange reactions, Mn ions were introduced in the lattice of CsPbBr 3 NPLs to generate bright orange emitting to create dual-luminescent CsPbBr 3 :Mn NPLs. A white emitting sample with a color coordinate of (0.304, 0.325) was finally fabricated using bright CsPbBr 3 :Mn NPLs and green-emitting CsPbBr 3 nanocrystals. This work broadened the application of perovskite for display and lighting. • CsPbBr 3 nanoplates with adjusted thickness and bright PL were created. • Mn doping resulted in the nanoplates with double-color emitting for white light emitting diodes. • Halogen ion exchange plays important for bright, stable, and tunable PL property. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, characterization and Li-ion intercalation properties of moundlily-like radial vanadium pentoxide (V 2 O 5 ) nanobelt clusters. The V 2 O 5 nanobelt clusters was successfully synthesized by a novel soft template assisted hydrothermal process followed by thermal annealing. The as-prepared products were characterized by X-ray diffraction, thermogravimetric analysis, FT-IR spectrometry, scanning electron microscopy and high resolution transmission electron microscopy. The obtained V 2 O 5 possesses a single-crystalline structure with a preferred orientation along the [0 1 0] crystal plane. Electrochemical analysis shows that the specific discharge capacity of the V 2 O 5 nanobelt clusters reaches 134 mA h/g at a current density of 2 A/g coupled with good cycle stability. [ABSTRACT FROM AUTHOR]

Abstract The poor charge separation of single-component semiconductor photocatalysts greatly restrains their practical application. Herein, we report an in situ anion-exchange strategy to controllably fabricate sunlight-driven p-n heterostructure photocatalyst BiOCl/BiOCOOH. In this synthetic process, the BiOCOOH microspheres not only act as the support to form heterostructures but also as Bi3+ supplier to generate BiOCl. Such an in situ anion-exchange route thus brought about the homogeneous distribution of BiOCl on the surface of BiOCOOH with tight interfacial contact. Under simulated solar illumination, the obtained BiOCl/BiOCOOH catalysts with p-n heterostructures show exceedingly superior photocatalytic activity against toxic pollutant (MO dye and TC antibiotic) to BiOCOOH and BiOCl. The optimal BiOCl/BiOCOOH, S3 sample has the highest photocatalytic activity with MO degradation rate constant of 0.0599 min−1, 2.9 or 9.7 folds higher than that of BiOCOOH or BiOCl. The alleviated charge separation and transfer as well as the flower-like structure mainly account for the enhanced performance. Radical scavenging experiments indicate that holes, OH and O 2 − collaboratively contribute to the degradation of pollutants. This work provides a novel sunlight-driven p-n heterojunction photocatalyst of BiOCl/BiOCOOH for wastewater treatment. Highlights • Novel BiOCl/BiOCOOH heterojunctions were prepared by a facile ion-exchange route. • Highly efficient and stable activity for removal of industrial dyes and tetracycline hydrochloride. • The synergistic effect of holes, OH and O 2 − resulted in pollutant degradation. [ABSTRACT FROM AUTHOR]

Developing a high-efficiency, stable and inexpensive bifunctional electrocatalyst/photocatalyst for hydrogen evolution reaction (HER) with suitable Gibbs free energy of hydrogen and rich electron transport channels remains a significant challenge. Herein, noble-metal-free Co nanoparticles decorated CePO 4 nanowires Co/CePO 4 were synthesized using Co-BTC/CePO 4 as a precursor via hydrothermal and calcination methods. A robust coupling heterostructure interface can be generated through carefully designed routes between Co nanoparticles and CePO 4 nanowires. In the HER process, the heterostructure interface can promote the composite catalysts conductivity, increase the active sites, charge-transfer efficiency, and adjust the desorption energy of hydrogen, thus enhancing their HER activity. Benefited from its specific structure, the obtained Co/0.1CePO 4 catalyst exhibits splendid electrocatalytic HER performance with an overpotential of only − 108 mV at − 10 mA cm−2 and a low Tafel slope of 85 mV decade−1, which is superior to many reported noble-metal-free catalysts. Especially, Co/0.1CePO 4 catalysts show an overpotential close to commercial 20 wt % Pt/C (−377 mV vs −340 mV) at a high current density of − 200 mA cm−2. Co/0.1CePO 4 catalyst also exhibits excellent photocatalytic hydrogen production rate (~87.5 μmol h−1) when working with organic photosensitizer Eosin Y. Furthermore, the Co/0.1CePO 4 catalyst reveals favorable stability in both electrocatalytic and photocatalytic HER. This research provides a new insight for fabricate efficient and stable composite HER catalysts. [Display omitted] • Composite of CePO 4 with Co as electro/photo-catalytic HER catalyst is reported. • Co/0.1CePO 4 exhibits excellent electrocatalytic HER performance with the overpotential of − 377 mV close to Pt/C (−340 mV) at high current density 200 mA cm−2. • Co/0.1CePO 4 shows superb photocatalytic HER performance with H 2 generation rate of 87.5 μmol h−1 when sensitized with Eosin-Y. • Mechanism of electro/photo-catalytic HER over Co/CePO 4 catalyst is proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mo reacted with BaF2 and formed BaMoO4. [•] The working temperature range of Fe–Cr based alloy was widened. [•] Tribological properties of composites strongly depended on the additives. [•] FM showed the excellent tribological properties from RT to 800°C. [ABSTRACT FROM AUTHOR]

High entropy alloy (HEA) thin films are extensively studied recently due to their propensity to display a combination of excellent properties such as high hardness, hydrophobicity, superior oxidation and corrosion resistance. Sputter deposition of thin films comprised of several elements typically requires the use of targets containing multiple elements, making both the stoichiometry and microstructure of the resulting films strongly dependent on the process parameters. In this study, HEA thin films of AlCoCrCu 0.5 FeNi were deposited at various radio frequency (RF) powers, from 200 to 300 W, to reveal how the power affects composition, microstructure and physical properties. X-ray diffraction (XRD) indicated a mixed phase of FCC and BCC and transmission electron microscopy (TEM) data revealed the presence of amorphous phases between the grain boundaries. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively showed an increase in grain size and surface roughness with increasing RF power. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Al 2 O 3 and Cr 2 O 3 protective oxide layers on the surface of all the HEA films. The highest concentration of Al (19.7%) was detected by energy dispersive spectroscopy (EDS) in the film deposited at the lowest power, which also had the highest nanoindentation hardness of 13 GPa. The hardness dropped to 4.5 GPa as power increased due to a reduction in Al concentration and an increase in average grain size. The film deposited at the highest power showed the highest hydrophobicity with a contact angle of 129°, while the lowest resistivity of 414 μΩ-cm was recorded for the sample deposited with the lowest power. This study shows the influence of deposition power on the microstructure and composition of the HEA thin films, demonstrating that the power can be an effective processing parameter to control various properties of AlCoCrCu 0.5 FeNi films. An understanding of how key process parameters affect the resulting thin film properties will enable application specific process optimization. • AlCoCrCu 0.5 FeNi thin films were deposited by RF magnetron sputtering from a single stoichiometric target at various powers. • Al concentration influences the structural and mechanical properties of the AlCoCrCu 0.5 FeNi thin films. • The microstructural evolution during the fabrication process was explained using the structure zone models (SZMs). • The role of RF power in controlling the microstructure and composition of the HEA films is revealed. • The films possess great promise as protective coatings for applications where high hardness, hydrophobicity and superior resistance to corrosion are critical. [ABSTRACT FROM AUTHOR]

In this work, WO 3 nanosheets are synthesized successfully through the hydrothermal method. Ru is thereafter efficiently loaded on the surface of WO 3 using the ethylene glycol-assisted solvothermal method. The gas sensing test shows that 0.5 wt% Ru-WO 3 exhibits the best performance towards xylene detection. Compared with the pure WO 3 sensor, the gas response of the sensor based on 0.5 wt% Ru-WO 3 in 100 ppm xylene increases from 11 to 73, and the operating temperature decreases from 375 °C to 280 °C. And an ultra-low detection limit of 25 ppb is obtained. In addition, the gas sensing performance of the Ru-loaded WO 3 sensor is much better than that of Au, Pt and Pd-loaded WO 3 sensors. The enhanced gas sensing performance can be attributed to the catalytic overflow of Ru and the formation of heterojunction between RuO 2 and WO 3. It is expected that this finding gives rise to further efforts on efficient and low-cost xylene sensors that are based on Ru-loaded WO 3. Image 1 • WO 3 nanosheets were prepared by a simple hydrothermal method and loaded Ru on WO 3 by ethylene glycol hydrothermal method. • Hydrothermal method could effectively loading Ru on WO 3. • Ru-WO 3 sensor has an ultra-low detection limit of 23 ppb to xylene. [ABSTRACT FROM AUTHOR]