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Abstract It is challenging to explore and prepare polyoxometalates-based nanomaterials (PNMs) with controllable morphologies and diversiform components. Herein, 3d–4f metals are introduced into isopolyoxometalates and Anderson-type polyoxometalates, CeCdW12 nanoflower and EuCrMo6 microflaky have been fabricated respectively. A series of control experiments are carried out to identify the impact factors on the rare morphologies in PNMs. Furthermore, upon excitation at 396 nm, the emission spectrum of EuCrMo6 displays five prominent f − f emitting peaks at 674, 685, 690, 707, and 734 nm that are assigned to Eu3+ 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions. Meanwhile, the VSM results show that the Cr+3 ions in EuCrMo6 display anti-ferromagnetic interactions when the temperature is lower than − 17.54 K. After rising temperature, this material exhibits paramagnetic property. This work opens up strategies toward the brand new morphologies and components of PNMs, endowing this kind of material with new functions.

Abstract The utilization of mixed cations is beneficial for taking the advantages of cations and achieving highly efficient perovskite solar cells (PSCs). Herein, the precisely small incorporation of CH(NH2)2 (FA) cations in methyl ammonium lead iodide (MAPbI3) enables the formation of compact, smooth perovskite film with high crystallinity. Consequently, the short-circuit current and the fill factor of the PSCs based on FA x MA1-x PbI3 perovskite are greatly improved, leading to the enhanced device efficiency. The champion PSC based on FA0.1MA0.9PbI3 exhibits a remarkably high efficiency of 22.02%. Furthermore, the PSCs based on FA0.1MA0.9PbI3 perovskite also show improved device stability. This work provides a simple approach to fabricate high-quality perovskite films and high-performance PSCs with better stability.

Abstract In this work, we fabricate poly(vinylpyrrolidone) (PVP)-treated Ruddlesden-Popper two-dimensional (quasi-2D) PPA2(CsPbBr3)2PbBr4 perovskite light-emitting diodes (PeLEDs) and achieved a peak brightness of 10,700 cd m−2 and peak current efficiency of 11.68 cd A−1, threefold and tenfold higher than that of the pristine device (without PVP), respectively. It can be attributed that the additive of PVP can suppress the pinholes of perovskite films owing to the excellent film-forming property, inhibiting the leakage current. Besides, PVP treatment facilitates the formation of compact perovskite films with defect reduction. Our work paves a novel way for the morphology modulation of quasi-2D perovskite films.

The utilization of mixed cations is beneficial for taking the advantages of cations and achieving highly efficient perovskite solar cells (PSCs). Herein, the precisely small incorporation of CH(NH2)2 (FA) cations in methyl ammonium lead iodide (MAPbI3) enables the formation of compact, smooth perovskite film with high crystallinity. Consequently, the short-circuit current and the fill factor of the PSCs based on FAxMA1-xPbI3 perovskite are greatly improved, leading to the enhanced device efficiency. The champion PSC based on FA0.1MA0.9PbI3 exhibits a remarkably high efficiency of 22.02%. Furthermore, the PSCs based on FA0.1MA0.9PbI3 perovskite also show improved device stability. This work provides a simple approach to fabricate high-quality perovskite films and high-performance PSCs with better stability. [ABSTRACT FROM AUTHOR]

Abstract We report on a thickness-dependent wetting property of WS2/Al2O3 and WS2/SiO2/Si structures. We prepared WS2 films with gradient thickness by annealing thickness-controlled WO3 films at 800 °C in sulfur atmosphere. Raman spectroscopy measurements showed step-like variation in the thickness of WS2 over substrates several centimeters in dimension. On fresh surfaces, we observed a significant change in the water contact angle depending on film thickness and substrate. Transmission electron microscopy analysis showed that differences in the surface roughness of WS2 films can account for the contrasting wetting properties between WS2/Al2O3 and WS2/SiO2/Si. The thickness dependence of water contact angle persisted for longer than 2 weeks, which demonstrates the stability of these wetting properties when exposed to air contamination.

In this work, we fabricate poly(vinylpyrrolidone) (PVP)-treated Ruddlesden-Popper two-dimensional (quasi-2D) PPA2(CsPbBr3)2PbBr4 perovskite light-emitting diodes (PeLEDs) and achieved a peak brightness of 10,700 cd m−2 and peak current efficiency of 11.68 cd A−1, threefold and tenfold higher than that of the pristine device (without PVP), respectively. It can be attributed that the additive of PVP can suppress the pinholes of perovskite films owing to the excellent film-forming property, inhibiting the leakage current. Besides, PVP treatment facilitates the formation of compact perovskite films with defect reduction. Our work paves a novel way for the morphology modulation of quasi-2D perovskite films. [ABSTRACT FROM AUTHOR]

Abstract As the field of nanotechnology continues to grow, evaluating the cytotoxicity of nanoparticles is important in furthering their application within biomedicine. Here, we report the synthesis, characterization, and cytotoxicity of nanoparticles of different morphologies of yttrium oxide, a promising material for biological imaging applications. Nanoparticles of spherical, rod-like, and platelet morphologies were synthesized via solvothermal and hydrothermal methods and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), light scattering, surface area analysis, thermogravimetric analysis (TGA), and zeta potential measurements. Nanoparticles were then tested for cytotoxicity with human foreskin fibroblast (HFF) cells, with the goal of elucidating nanoparticle characteristics that influence cytotoxicity. Cellular response was different for the different morphologies, with spherical particles exhibiting no cytotoxicity to HFF cells, rod-like particles increasing cell proliferation, and platelet particles markedly cytotoxic. However, due to differences in the nanoparticle chemistry as determined through the characterization techniques, it is difficult to attribute the cytotoxicity responses to the particle morphology. Rather, the cytotoxicity of the platelet sample appears due to the stabilizing ligand, oleylamine, which was present at higher levels in this sample. This study demonstrates the importance of nanoparticle chemistry on in vitro cytotoxicity, and highlights the general importance of thorough nanoparticle characterization as a prerequisite to understanding nanoparticle cytotoxicity.

As the field of nanotechnology continues to grow, evaluating the cytotoxicity of nanoparticles is important in furthering their application within biomedicine. Here, we report the synthesis, characterization, and cytotoxicity of nanoparticles of different morphologies of yttrium oxide, a promising material for biological imaging applications. Nanoparticles of spherical, rod-like, and platelet morphologies were synthesized via solvothermal and hydrothermal methods and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), light scattering, surface area analysis, thermogravimetric analysis (TGA), and zeta potential measurements. Nanoparticles were then tested for cytotoxicity with human foreskin fibroblast (HFF) cells, with the goal of elucidating nanoparticle characteristics that influence cytotoxicity. Cellular response was different for the different morphologies, with spherical particles exhibiting no cytotoxicity to HFF cells, rod-like particles increasing cell proliferation, and platelet particles markedly cytotoxic. However, due to differences in the nanoparticle chemistry as determined through the characterization techniques, it is difficult to attribute the cytotoxicity responses to the particle morphology. Rather, the cytotoxicity of the platelet sample appears due to the stabilizing ligand, oleylamine, which was present at higher levels in this sample. This study demonstrates the importance of nanoparticle chemistry on in vitro cytotoxicity, and highlights the general importance of thorough nanoparticle characterization as a prerequisite to understanding nanoparticle cytotoxicity. [ABSTRACT FROM AUTHOR]

It is challenging to explore and prepare polyoxometalates-based nanomaterials (PNMs) with controllable morphologies and diversiform components. Herein, 3d–4f metals are introduced into isopolyoxometalates and Anderson-type polyoxometalates, CeCdW12 nanoflower and EuCrMo6 microflaky have been fabricated respectively. A series of control experiments are carried out to identify the impact factors on the rare morphologies in PNMs. Furthermore, upon excitation at 396 nm, the emission spectrum of EuCrMo6 displays five prominent f − f emitting peaks at 674, 685, 690, 707, and 734 nm that are assigned to Eu3+ 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions. Meanwhile, the VSM results show that the Cr+3 ions in EuCrMo6 display anti-ferromagnetic interactions when the temperature is lower than − 17.54 K. After rising temperature, this material exhibits paramagnetic property. This work opens up strategies toward the brand new morphologies and components of PNMs, endowing this kind of material with new functions. [ABSTRACT FROM AUTHOR]