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Titanium dioxide (TiO2) has been widely studied as a photocatalyst owing to its advantages of low cost, good stability, and nonpollution. However, they can only be excited by ultraviolet light, resulting in low utilization of solar energy and limited photocatalytic efficiency. In recent years, researchers have found that the nonprecious metal Al can effectively improve the photocatalytic performance of TiO2. However, the current studies focus only on enhancing the ultraviolet photocatalysis performance of semiconductors with Al on the substrate. In this study, Al nanoparticles (NPs) and TiO2 were prepared into composite materials. The effects of ligand, Al particle size, and the molar ratio of Al and TiO2 on the photocatalytic degradation of methylene blue (MB) by Al NPs and TiO2 composites (Al NPs/TiO2) were investigated. The results showed that the Al NPs/TiO2 prepared with a particle size of 200 nm of Al, glutathione as the ligand bridge, and an Al:TiO2 ratio of 2:1 were the most effective for the degradation of MB. The degradation rate of 5 mg/L MB solution within 70 min under visible light was up to 99.5%, which was three times higher than that of P25 TiO2. The photocatalytic performance was further enhanced under sunlight with a degradation rate of 99.7% within 50 min, which is four times higher than that of P25 TiO2 under the same light source. Therefore, Al NPs/TiO2 is a potential photocatalytic material for the treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

The issue of water pollution has emerged as a formidable challenge, prompting a pressing need for solutions. The utilization of metal nanoparticles with surface plasmon resonance and semiconductor composite photocatalysts is regarded as a highly effective approach to solve this problem. g-C3N4 is an effective catalyst for the degradation of organic pollutants. Its photocatalytic performance is usually enhanced by the use of the noble metal Au Ag. However, the high cost of these materials limits their application. In this study, we present the synthesis of Al NPs/g-C3N4 nanocomposites using the bridging effect of ligands. The characterized of transmission electron microscopy (TEM), X-ray diffractometer (XRD) and ultraviolet-visible spectroscopy (UV-Vis) proved that Al NPs/g-C3N4 with a wider light absorption range were successfully synthesized. The effects of ligands, (glutathione (GSH), glutamic acid (GAG), and cysteine (CYS)), Al diameter (40 to 200 nm) and the ratio of Al to g-C3N4 (1:1 to 5:1) on the photocatalytic degradation of methylene blue (MB) by Al NPs/g-C3N4 were also evaluated. The results showed that the optimum degradation efficiency of Al NPs/g-C3N4 for MB at 5 mg/L reached 100% within 60 min, which was 11 times higher than that of pure g-C3N4. The principal analysis of Al enhancing the photocatalytic performance of g-C3N4 was studied through transient photocurrent spectroscopy (TPC), electrochemical impedance spectroscopy (EIS), and steady-state transient fluorescence spectroscopy (PL). The results confirmed that hot carriers generated by localized surface plasmon resonance (LSPR) of Al nanoparticles increase the carrier concentration. In addition, the Schottky barrier generated by Al and g-C3N4 could also improve the carrier separation rate and increase the carrier lifetime. This work is expected to solve the problem of organic wastewater treatment and lay the foundation for subsequent research on photocatalysis. [ABSTRACT FROM AUTHOR]

TiO2 is a catalyst that can effectively degrade organic pollutants with the following advantages, low cost, simplicity, and pollution-free nature. In recent years, the non-noble plasmonic metal Al has effectively improved the photocatalytic performance of TiO2. However, the current reports are limited to the photocatalytic performance of Al/TiO2 on the substrate, which requires expensive large-scale vacuum equipment. In this study, monodispersed Al particles were proposed to enhance the photocatalysis of TiO2. The localized surface plasmon resonance (LSPR) effect of Al is proven by finite difference time domain method (FDTF) simulation. Then, Al/TiO2 composites were prepared by combining monodispersed Al and TiO2. The influence of ligand (glutathione (GSH), glutamic acid (GAG), or 3-mercaptopropane acid (MPA)), Al size (40 to 300 nm), and the ratio of Al to TiO2 (0.5:1 to 10:1) on the photocatalytic degradation of methylene blue (MB) by Al/TiO2 were discussed. The obtained results showed that the Al/TiO2 composite which were prepared with 200 nm Al particles, GSH as the ligand bridge, and an Al:TiO2 ratio of 1:1 had the best MB degradation effect. It can degrade 97.7% of 10 mg/L MB in 100 min. The reaction rate of the Al/TiO2 composite with the optimal photocatalytic performance is k=3.36×10-2 min-1, which is 10 times that of P25 TiO2. In addition, Al/TiO2 has a good photocatalytic effect on rhodamine B (RhB) and crystal violet (CV). Therefore, Al/TiO2 composites with the advantage of high efficiency are a type of potential photocatalytic material that can be used for the photocatalytic treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

In order to facilitate the synthesis of this compound by researchers who are interested in this material, we introduce the specific steps of the synthesis of this material in detail. At the same time, we believe that the geometric error of the sample holder in collecting the crystallographic data of the sample as suspected by the authors of this Comment does not exist. [ABSTRACT FROM AUTHOR]

A new 3D open-framework potassium ferrite, K2Fe4O7 (1), has been successfully synthesized under hydrothermal conditions. The framework of 1 consists of both FeO6 octahedral and FeO4 tetrahedral units with shared vertices and edges where there are 6- and 3-ring channels parallel to the trigonal a- and c-axes, enabling many highly mobile potassium ions to move quickly through the channels. The K+ ion conductivity of the polycrystalline sample was 5.0 × 10−2 S cm−1 at room temperature. Interestingly, conductivities along the a-axis direction in single crystal K2Fe4O7 reached 3.5 × 102 S cm−1 at 25 °C and 5.0 × 102 S cm−1 at 500 °C with an activation energy of 0.08 eV. The conductor possessed a wide voltage stability up to 5 V vs. K/K+. Using the K2Fe4O7 electrolyte, we demonstrate an all-solid-state potassium metal battery employing a Prussian blue cathode with a high charge/discharge rate of 250C (charge/discharge in 14 s, 1C = 87 mA h g−1). [ABSTRACT FROM AUTHOR]

AgNbO3 is a weak ferroelectric with antiferroelectricity due to Ag displacements at room temperature. A dielectric anomaly at 250 K, which has not been observed previously, reveals a transition between the weak ferroelectric phase (M1 phase) at the higher temperature and a new ferroelectric phase (M0 phase) at the lower temperature in AgNbO3. This transition was further verified by the pyroelectric current and differential scanning calorimetry measurements. The spontaneous polarization value is found to be much larger in the M0 phase than that of the M1 phase. A well-defined saturating ferroelectric hysteresis loop can also be observed at 77 K, showing a remnant polarization value of 2.4 μC/cm2 and a coercive field of 25 kV/cm. All the above results indicate that the larger polarization of the M0 phase mainly comes from the alignment of the antiferroelectric displacements of the Ag atoms. [ABSTRACT FROM AUTHOR]

AgNbO3 is a weak ferroelectric with antiferroelectricity due to Ag displacements at room temperature. A dielectric anomaly at 250 K, which has not been observed previously, reveals a transition between the weak ferroelectric phase (M1 phase) at the higher temperature and a new ferroelectric phase (M0 phase) at the lower temperature in AgNbO3. This transition was further verified by the pyroelectric current and differential scanning calorimetry measurements. The spontaneous polarization value is found to be much larger in the M0 phase than that of the M1 phase. A well-defined saturating ferroelectric hysteresis loop can also be observed at 77 K, showing a remnant polarization value of 2.4 μC/cm2 and a coercive field of 25 kV/cm. All the above results indicate that the larger polarization of the M0 phase mainly comes from the alignment of the antiferroelectric displacements of the Ag atoms. [ABSTRACT FROM AUTHOR]

The title compound is hydrothermally prepared from a solution of Y(NO3)3, NiSO4, MnO2, and KOH (autoclave, 533 K, 3 d) and characterized by powder XRD, SEM, XPS, and electric and magnetic measurements. [ABSTRACT FROM AUTHOR]