Strong electron coupling of FeP4/Ni2P to boost highly-efficient electrochemical nitrate reduction to ammonia.

Electrochemical reduction of contaminated nitrate to ammonia (NRA) opens a new window for mass production of ammonia and the alleviation of energy crises and environmental pollution. However, fabricating effective catalysts for the NRA still faces significant challenges. Herein, a highly-efficient NRA catalyst, FeP4/Ni2P, was successfully constructed. The strong electron coupling at heterointerfaces of FeP4/Ni2P promoted the generation of abundant active hydrogen *H, inhibited the competition of the HER, accelerated the hydrogenation of the NRA. Benefiting from these, the catalyst displays good NRA catalytic activity in the neutral electrolyte, with the NH3 FE of 97.83 ± 0.091 %, NH3 selectivity of 98.67 ± 0.50 %, NH3 yield rate of 0.262 ± 0.01 mmol·h-1·cm-2, and NO3- conversion rate of 93.02 ± 0.14 %. The DFT theoretical calculations demonstrated that the FeP4/Ni2P heterointerfaces played a critical role in shearing the H-OH bonds of water, resulting in generating more active hydrogen as a key NRA hydrogenation source, and hindering the *H dimerization to form H2, enhancing the NH3 selectivity. This work has a certain reference value for designing excellent catalysts for the NRA.

The role of various components in Ru-NiCo alloys in boosting the performance of overall water splitting.

Understanding the synergistic mechanism of multi-component alloys is crucial and challenging for overall water splitting. Herein, Ru-NiCo0.5-600 °C and Ru-Ni0.75Co with excellent electrocatalytic activity are designed and synthesized. The Ru-NiCo0.5-600 °C alloy exhibits remarkable HER activity with an overpotential of 42, 77 and 93 mV at 10 mA cm-2 in alkaline, acidic and neutral conditions, and the Ru-Ni0.75Co electrocatalyst presents outstanding OER activity with an overpotential of 176 mV at 10 mA cm-2 in 1.0 M KOH. The Ru-NiCo0.5-600 °C ||Ru-Ni0.75Co cell requires only 1.48 and 1.69 V to reach 10 and 100 mA cm-2 towards overall water splitting. A series of experiments reveal that the strong electronic coupling among Ru, Ni and Co regulates the electronic structure and enhances the intrinsic catalytic activity and stability of the as-synthesized Ru-NiCo electrocatalysts. Systematic experimental and theoretical results prove that Ni atoms act as the active sites of dissociating water, while Ru and Co are respectively the active centers of proton and hydroxyl adsorption for HER and OER. Our work provides a new perspective for profoundly understanding the synergistic effect of multi-component alloys towards water splitting.

CircCRIM1 promotes nasopharyngeal carcinoma progression via the miR-34c-5p/FOSL1 axis.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a rare malignancy with multiple risk factors (Epstein-Barr virus, etc.) that seriously threatens the health of people. CircRNAs are known to regulate the tumorigenesis of malignant tumours, including NPC. Moreover, circCRIM1 expression is reported to be upregulated in NPC. Nevertheless, the impact of circCRIM1 on NPC progression is not clear. METHODS: An MTT assay was performed to assess cell viability. In addition, cell invasion and migration were assessed by the transwell assay. Dual luciferase assays were performed to assess the association among circCRIM1, miR-34c-5p and FOSL1. Moreover, RT-qPCR was applied to assess mRNA levels, and protein levels were determined by Western blot. RESULTS: CircCRIM1 and FOSL1 were upregulated in NPC cells, while miR-34c-5p was downregulated. Knockdown of circCRIM1 significantly decreased the invasion, viability and migration of NPC cells. The miR-34c-5p inhibitor notably promoted the malignant behaviour of NPC cells, while miR-34c-5p mimics exerted the opposite effect. Moreover, circCRIM1 could bind with miR-34c-5p, and FOSL1 was identified to be downstream of miR-34c-5p. Furthermore, circCRIM1 downregulation notably inhibited the proliferation and invasion of NPC cells, while this phenomenon was significantly reversed by FOSL1 overexpression. CONCLUSION: Silencing circCRIM1 inhibited the tumorigenesis of NPC. Thus, circCRIM1 might be a novel target for NPC.

The morphology evolution, tunable down-conversion luminescence, and energy transfer of [CaY]F2 crystals doped with Li+/Ce3+/Tb3.

Octahedral [CaY]F2 crystals with an average particle size of 1 µm were synthesized via a mild one-step hydrothermal route without employing any surfactants. Various morphologies, including cubes, truncated cubes, truncated octahedrons, and spheres, were achieved via manipulating the amount of EDTA used, and a possible growth mechanism was proposed based on the surface energies of different crystal planes and the influence of the surfactant. XRD, SEM, EDS, TEM, HRTEM, and PL analysis were used to characterize the products. The effects of the morphologies and Li+ doping concentrations on the luminescence intensities of the [CaY]F2:Ce3+/Tb3+ phosphors were explored, and the strongest luminescence intensity is obtained when the sample is cubic with (100) crystal faces and the doping concentration of Li+ is 0.25 mol%. Additionally, multicolor emission (blue → aquamarine blue → green) was obtained from [CaY]F2:Ce3+/Tb3+ phosphors via adjusting the doping concentration of Tb3+, which resulted from the Ce3+ → Tb3+ energy transfer behavior; the energy transfer here happened through a dipole-dipole mechanism. This work may result in the as-synthesized phosphors having great application potential in many optoelectronic device fields, such as in displays and multicolor lighting.

Temperature sensing performance based on up-conversion luminescence in hydrothermally synthesized Yb3+/Er3+ co-doped NaScF4 phosphors.

NaScF4:Yb3+/Er3+ crystals were successfully hydrothermally synthesized using distilled water as a single solvent. The crystal phase and morphology were characterized by XRD and SEM. Compared with organic solvents such as ethanol, ethylene glycol and ether, the molar ratio of Na/F/Sc plays an important role in the synthesis of NaScF4 crystals. Morphological control was achieved by changing the types of additives, and the relationship between morphology and luminescence properties was explored. The NaScF4:Yb3+/Er3+ phosphors exhibit strong green and red UC emissions under the excitation of 980 nm NIR. Optimal concentrations of Yb3+ and Er3+ for up-conversion luminescence performance were identified as 10% and 2%, respectively. Without any subsequent heat treatment process, the obtained NaScF4:10%Yb3+/2%Er3+ showed good temperature sensitivity. The temperature sensing ability was investigated by employing the dependence of the fluorescence intensity ratio (FIR) of the two thermal coupling energy levels of Er3+ (2H11/2→4I15/2 and 4S3/2→4I15/2) on temperature; the maximum sensitivity SA/SR was 0.00256 K-1/0.00317 K-1 at 548 K, and it increased to 0.00328 K-1/0.00413 K-1 after adding EDTA. In addition, an evaluation of temperature uncertainty during temperature measurement was performed, and was found to be 0.073 K and 0.095 K in the presence and absence of EDTA, respectively. Compared with some other reported materials, the obtained material shows a relatively superior temperature sensitivity, which provides new ideas for the improvement of temperature-sensitive materials.

A lanthanide ion-doped Ba3Sc2F12 phosphor: hydrothermal synthesis, morphological control, energy transfer, and temperature-sensing performance.

Ba3Sc2F12 crystals were synthesized by a facile one-step hydrothermal method with Ba/Sc raw material in a ratio of 3 : 2. With the F/Sc ratio increasing from 4 to 8, the obtained crystal's morphology evolved gradually from a strip to a chocolate shape; further, the use of the additives, such as CTAB and EDTA, the obtained crystal's morphology changed from strip to cubic. The energy transfer of Ce3+→ Tb3+ in the Ba3Sc2F12 host was also explored, and it was found to belong to a dipole-dipole interaction mechanism; the color of the light could be adjusted from blue-violet to green due to the different energy transfer efficiencies at different Ce3+ and Tb3+ ion-doping concentrations. Because of the thermal coupling level of Er3+ (2H11/2→4I15/2 and 4S3/2→4I15/2), Ba3Sc2F12:14%Yb3+,2%Er3+ phosphors showed an excellent temperature-sensing ability with SA(max) = 0.0043 K-1 and Tmax = 523 K, which are much better than the previously reported values for Yb3+/Er3+ co-doped systems. The as-prepared lanthanide ion-doped phosphors might have potential to serve as color light/displays and temperature control/sensors.