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Thin films of metal–organic frameworks (MOFs) on polymer substrates and MOF/polymer mixed-matrix membranes play crucial roles in advancing the field of gas separation membranes. In this paper, we present a novel method for the direct formation of continuous ZIF-8 crystal films on a polymer substrate doped with Zn²+. Our approach involves ion exchange between the doped zinc ions within the substrate and sodium ions in the presence of a CH3COONa additive, as well as interfacial complexation with eluted zinc ions and 2-methylimidazole (2-MeIM). The key factors affecting the formation of ZIF-8 crystals on the substrate were the concentrations of CH3COONa and 2-MeIM. A time-course analysis revealed that the nucleation rate during the early stages of the reaction significantly affected the surface morphology of the resulting ZIF-8 crystal films. Specifically, a higher nucleation rate led to the formation of continuous small ZIF-8 crystal films. This innovative approach enables the fabrication of densely packed, uniform ZIF-8 crystal films.

SnTe is the most widely studied p-type thermoelectric (TE) alternative to PbTe. In this study, we prepared a nanostructured SnTe bulk material via spark plasma sintering from a precursor synthesized by a chemical precipitation process without using organic molecules. The sintered sample comprised tiny grains (100–300 nm) with high-density grain boundaries. Eventually, because the material would contain no impurities acting as scattering nodes of charge carriers, the material exhibited a relatively high electrical conductivity of 7.07 × 105 Sm−1 at 310 K. The material demonstrated low lattice thermal conductivity (0.87 Wm−1K−1 at 764 K), which can be owing to the increasing phonon scattering at grain boundaries. The maximum ZT was 0.31 at 764 K in the measured temperature range. This study provides a method for the design of phase-pure and surfactant-free SnTe thermoelectric materials that exhibit low lattice thermal conductivity and high carrier mobility using a chemical synthetic approach.

The synthesis of high-purity nanocrystals as precursors is important to fabricate nanostructured thermolectronics with high thermoelectric performance. In this study, single-phase Bi2−xSbxTe3.0 (x = 1.5, 1.6, and 1.7) nanocrystals without the significant inclusion of impurities were successfully synthesized through a chemical precipitation process at room temperature. The reaction rate of this process is extremely high because it is based on the charge compensation of the reactive metal ions, resulting in crystal growth suppression. The size of the Bi0.4Sb1.6Te3.0 nanocrystals was controlled from a single-nanometer scale to a submicron scale by refluxing with several organic solvents possessing different boiling points. These precursors are expected to be suitable for the preparation of bulk thermoelectric materials with controlled grain sizes.

Hyperactivity of the gene NRAS contributes to the proliferation and metastatic nature of many types of cancer cells. Here, the authors show that NRAS can be controlled by an anionic phthalocyanine coordinating Zn2+ in combination with photo-irradiation.