Induced abundant oxygen vacancies in Sc2VO5-δ /g-C3N4 heterojunctions for enhanced photocatalytic degradation of levofloxacin

Sc₂VO_5-δ /g-C₃N₄ heterojunctions (SVCs) with abundant oxygen vacancies (OVs) were synthesized by ultrasonic exfoliation combined with the thermal etching method. The structures, OVs and spatial separation of the photogenerated carriers were systematically characterized. The results manifested that the SVCs were successfully constructed via the strong interaction between g-C₃N₄ (CN) and Sc₂VO_5-δ (SV). The SVCs possessed a higher concentration of OVs than that of pristine CN and SV. The formation of the SVC heterostructures and the optimization of the OVs were the two major factors to accelerate the separation of the charge carriers and finally to improve the photocatalysis performance. The as-prepared 10%SVC (containing 10 wt% of SV) catalyst exhibited the highest OV concentration and the best photocatalytic performance. The levofloxacin (LVX) photodegradation activity showed a positive correlation with the OV concentration. The photocatalytic degradation efficiencies were 89.1, 98.8 and 99.0% on 10%SVC for LVX, methylene blue (MB) and rhodamine B (RhB), respectively. These photodegradation processes followed the pseudo first order kinetic equation. The apparent rate constant (k _app) of LVX degradation on 10%SVC was 11.0 and 7.5 times that of CN and SV. The h⁺, ˙OH and ˙O₂ ^- were the major reactive species in the photodegradation process.

A novel red phosphor Ca2 YNbO6 :Eu3+ for WLEDs

Due to the advantages of good physicochemical properties, thermal stability, and optical properties, double perovskite compounds have received extensive attention. On this basis, a new type of red phosphor, Ca₂ YNbO₆ :xEu³⁺ , was synthesized using a high-temperature solid-phase method. Its phase purity, morphology, elemental composition, absorption spectrum, photoluminescence, thermal stability, and Commission Internationale de l'éclairage (CIE) chromaticity coordinates were thoroughly investigated. The results display that there is no impurity phase in the samples and the convergence factor R_wp  = 14.2%; the microscopic particles are uniform and full, and the distribution of each element is uniform. The energy band gap ΔE is between 3.71 eV and 3.65 eV. The luminescence intensity is the best when the doped Eu³⁺ concentration x reaches 0.4, and emits 612 nm red light (⁵ D₀ →⁷ F₂ ) under 465 nm excitation, and the concentration quenching is attributed to a d-d interaction. The luminescence intensity at 425 K was still 75% of the room temperature luminescence intensity, which indicates that the thermal stability is extremely superior. The CIE chromaticity coordinates (0.6534, 0.3455) of the Ca2YNbO6:0.4Eu³⁺  phosphors are very close to National Television Standards Committee (0.670, 0.330), and the samples have low correlated colour temperature (2656 K) and high colour purity (99.90%). All findings suggest that Ca₂ YNbO₆ :Eu³⁺ can serve as a substitute for red phosphor in WLEDs.

A Triazole Functionalized txt-Type Metal-Organic Framework with High Performance for CH4 Uptake and Selective CO2 Adsorption

The metal-organic framework (MOF) NTUniv-54 (NTUniv = Nantong University) was assembled via utilizing click chemistry with densely decorated trizole units and exposed metal sites, which exhibited the best methane working ability (197 cm³·cm^-3 from 100 to 5 bar and 177 cm³·cm^-3 from 65 to 5 bar at 298 K), and the lowest CO₂ Q_st of 22.8 kJ·mol^-1 in all triazole-MOFs at room temperature.

All-Liquid-Phase Reaction Mechanism Enabling Cryogenic Li-S Batteries

The sluggish solid-solid conversion kinetics from Li₂S₄ to Li₂S during discharge is considered the main problem for cryogenic Li-S batteries. Herein, an all-liquid-phase reaction mechanism, where all the discharging intermediates are dissolved in the functional thioether-based electrolyte, is proposed to significantly enhance the kinetics of Li-S battery chemistry at low temperatures. A fast liquid-phase reaction pathway thus replaces the conventional slow solid-solid conversion route. Spectral investigations and molecular dynamics simulations jointly elucidate the greatly enhanced kinetics due to the highly decentralized state of solvated intermediates in the electrolyte. Overall, the battery brings an ultrahigh specific capacity of 1563 mAh g^-1_{sulfur in the cathode} at -60 °C. This work provides a strategy for developing cryogenic Li-S batteries.

Organic Nanobowls Modified Thin Film Composite Membrane for Enhanced Purification Performance toward Different Water Resources

The structure and composition of nanofillers have a significant influence on polyamide nanofiltration (NF) membranes. In this work, an asymmetric organic nanobowl containing a concave cavity was synthesized and incorporated into a polyamide layer to prepare thin film nanocomposite (TFN) membranes via an interfacial polymerization process. Benefiting from the hydrophilicity, hollow cavity and charge property of the compatible organic nanobowls, the separation performance of the developed TFN membrane was significantly improved. The corresponding water fluxes increased to 119.44 ± 5.56, 141.82 ± 3.24 and 130.27 ± 2.05 L/(m²·h) toward Na₂SO₄, MgCl₂ and NaCl solutions, respectively, with higher rejections, compared with the control thin film composite (TFC) and commercial (CM) membranes. Besides this, the modified TFN membrane presented a satisfying purification performance toward tap water, municipal effluent and heavy metal wastewater. More importantly, a better antifouling property of the TFN membrane than TFC and CM membranes was achieved with the assistance of organic nanobowls. These results indicate that the separation performance of the TFN membrane can be elevated by the incorporation of organic nanobowls.

Multi-dimensional architecture of Ag/α-Ag2WO4 crystals: insights into microstructural, morphological, and photoluminescence properties

Varying the concentration of ethylenediamine resulted in hollow or solid Ag/α-Ag₂WO₄ microflowers that emit light in the red region or in the blue region, respectively.

Au/MoS2/Ti3C2 composite catalyst for efficient photocatalytic hydrogen evolution

The Au/MoS₂/Ti₃C₂ composite catalyst has efficient photocatalytic hydrogen evolution performance.