Effect of Tb3+ and Ce3+ Co-doping on the Structure and Photoluminescence Properties of Hexagonal Boron Nitride Phosphors.

In the paper, we have successfully prepared hexagonal boron nitride (h-BN:Tb3+, Ce3+) phosphors with melamine as the nitrogen source. The X-ray powder diffraction patterns confirm that the sample possesses a hexagonal crystal structure within the P 6 ¯ m2 space group. It is interesting that the co-doping combination of Tb3+ and Ce3+ can markedly enhance the threshold concentration of doped activators within the limited solid solution of h-BN phosphors. Under 302 nm excitation, the h-BN:Ce3+ phosphors exhibit broadband blue light emission at 406 nm. In h-BN:Tb3+, Ce3+ phosphors, the co-doping of Ce3+ not only ensures high phase purity but also results in strong green light emission. The energy transfer efficiency from Ce3+ to Tb3+ is about 55%. The fluorescence lifetime increases with the increase of Ce3+ and Tb3+ concentration, and the fluorescence lifetime of h-BN:0.025Tb3+, 0.05Ce3+ phosphor reached 2.087 ms. Additionally, the h-BN:0.025Tb3+, 0.05Ce3+ phosphor exhibits excellent thermal performance with an activation energy value of 0.2825 eV. Moreover, the photoluminescence quantum yield of the sample exceeds 52%. Therefore, the h-BN:Tb3+, Ce3+ samples can be used as green phosphors for solid state lighting and fluorescent labeling.

The amino acid transporter SLC7A11-mediated crosstalk implicated in cancer therapy and the tumor microenvironment.

The solute carrier family 7 member 11 (SLC7A11), an amino acid transporter protein is frequently overexpressed in human malignancies. The expression and activity of SLC7A11 is finely regulated by oncogenes and tumor suppressors in tumor cells through various mechanisms and is highly specific for cystine and glutamate. Cystine is mainly transported intracellularly by SLC7A11 in the tumor microenvironment (TME) and is involved in GSH synthesis, which leads to ferroptosis resistance in tumor cells and promotes tumorigenesis and progression. The downregulation of SLC7A11 presents a unique drug discovery opportunity for ferroptosis-related diseases. Experimental work has shown that the combination of targeting SLC7A11 and tumor immunotherapy triggers ferroptosis more potently. Moreover, immunotargeting of SLC7A11 increases the chemosensitivity of cancer stem cells to doxorubicin, suggesting that it may act as an adjuvant to chemotherapy. Thus, SLC7A11 could be a promising target to overcome resistance mechanisms in conventional cancer treatments. This review provides an overview of the regulatory network of SLC7A11 in the TME and progress in the development of SLC7A11 inhibitors. In addition, we summarize the cytotoxic effects of blocking SLC7A11 in cancer cells, cancer stem cells and immune cells.

Catalytic oxidation of VOCs over 3D@2D Pd/CoMn2O4 nanosheets supported on hollow Al2O3 microspheres.

Catalytic oxidation is a promising method for removing harmful volatile organic compounds (VOCs). Therefore, exploring high-efficiency catalysts for catalyzing VOCs is of great significance to the realization of an environment-friendly and sustainable society. Here, a series of 3D@2D constructed Al2O3@CoMn2O4 microspheres with a hollow hierarchical structure supporting Pd nanoparticles was successfully synthesized. The introduction of hollow Al2O3 for the in situ vertical growth of 2D CMO spinel materials constructs a well-defined core - shell hollow hierarchical structure, leading to larger specific surface area, more accessible active sites and promoted catalytic activity of support material. Additionally, theoretical calculations also indicate that the addition of Al2O3 as the support material strengthens the adsorption of toluene and oxygen on CoMn2O4, which promotes their activation. The dispersion of Pd further strengthens the low-temperature reducibility along with more active surface oxygen species and lower apparent activation energy. The optimum 1 wt% Pd/h-Al@4CMO catalyst possesses the lowest apparent activation energy for toluene of 77.4 kJ mol-1, showing the relatively best catalytic activity for VOC oxidation, reaching 100% toluene, benzene, and ethyl acetate conversion at 165, 160, and 155 °C, respectively. Meanwhile, the 1 wt% Pd/h-Al@4CMO sample possesses excellent catalytic stability, outstanding selectivity, and good moisture tolerance, which is an effective candidate for eliminating VOCs contaminants.

Low Temperature Combustion of VOCs with Enhanced Catalytic Activity Over MnO2 Nanotubes Loaded with Pt and Ni-Fe Spinel.

MnO2 nanotubes loaded with Pt and Ni-Fe spinel were synthesized using simple hydrothermal and sol-gel techniques. After loading with Ni-Fe spinel, the specific surface area of the material increases 3-fold. This change helped to provide more active sites and facilitated the association between the catalyst and volatile organic compounds (VOCs). X-ray photoelectron spectroscopy determined that the adsorbed oxygen concentrations were all greatly increased after Pt loading, indicating that Pt promoted the adsorption of oxygen and so accelerated the combustion process. The performance of the catalyst after loading with 2 wt % Pt was greatly improved, such that the T90 for benzene decomposition was decreased to 113 °C. In addition, the 2% Pt/2Mn@NFO exhibited excellent low-temperature catalytic activity when reacting with low concentrations of toluene and ethyl acetate. This work therefore demonstrates a viable new approach to the development of Mn-based catalysts for the low temperature catalytic remediation of VOCs.

Hollow Mesoporous Co3 O4 -CeO2 Composite Nanotubes with Open Ends for Efficient Catalytic CO Oxidation.

Catalytic performance is heavily dependent on how the structures of nanomaterials are designed. Co3 O4 -CeO2 composite nanotubes with open ends and mesoporous structures were fabricated through a facile and environmentally friendly reaction. The mesoporous Co3 O4 nanotubes were synthesized by the calcination of cobalt-aspartic acid (Co-Asp) nanowires and coated with a CeO2 shell. The composite nanotubes were characterized by SEM, TEM, XRD, and X-ray photoelectron spectroscopy. The composite materials comprise a combination of Co3 O4 nanotubes and CeO2 nanoparticles with a hollow and mesoporous bimetallic oxide structure. The large BET surface area led to a higher degree of accessible active sites compared with other Co3 O4 -CeO2 composite nanomaterials with other structures. The resulting Co3 O4 -CeO2 -26.3 wt % composite nanotubes, with a CeO2 content of approximately 26.3 wt %, achieved 100 % CO conversion at 145 °C. Additionally, the synergistic effect between the two metal oxides comprising the Co3 O4 -CeO2 composite nanotubes was demonstrated by the enhanced catalytic activity compared with pure Co3 O4 nanotubes and CeO2 nanoparticles.