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A novel cage-based crystalline covalent organic framework, i.e. Cage-COF-TT (TT = triammonia–terephthalaldehyde), was prepared from a prism-like triammonia-containing molecular cage and terephthalaldehyde. Its ordered structure and porosity are expected to ensure efficient drug delivery as a potent carrier. The excellent cell viability of Cage-COF-TT was testified through MTT assays with respect to both normal mouse cells and normal human hepatocyte cells. In terms of drug delivery performance, Cage-COF-TT exhibit a high loading capacity and efficient drug release profile in a simulated body fluid environment. This work offers new insights into the design and development of a COF-based drug carrier and inspires the development of versatile tools for biomedical applications.

A stable nanoscaled single-excitation ratiometric luminescent pH sensor (MPDB-PCN) over a broad pH range from 2.5 to 8.6 is fabricated through post-synthetic modification of PCN-224 with naphthalimide-derived molecules. Due to the rapid, sensitive and linear response to pH, MPDB-PCN is capable of detecting 3-nitropropionic acid (3-NPA), an acid neurotoxin in food safety, with a low detection limit of 15 μM in sugarcane juice.

A new AgCl/Ag/AgFeO2 composite was synthesized for the first time via a simple precipitation method. The very detailed characterizations were enforced in photocatalytic activity and stability. The photocatalytic performance was studied by the degradation of the rhodamine B (RhB, a cationic dye) under visible irradiation. The as-prepared AgCl/Ag/AgFeO2 photocatalyst exhibited excellent photocatalytic activity and stability under the visible light region compared to pure AgCl and AgFeO2. About 97.47% of RhB can be removed in 60 min by the optimized AgCl/Ag/AgFeO2 composite, which was ∼2.26 and ∼10.83 times as fast as that pure AgCl and pure AgFeO2. After three cycles visible light irradiation experiments found that degradation rate of RhB reached 76.35%, which was still higher than pure AgCl and AgFeO2. The obviously enhanced photocatalytic activity of AgCl/Ag/AgFeO2 composites can be attributed to the efficient separation of electron-hole pairs of the Z-scheme heterostructure between AgCl, Ag and AgFeO2. In this study, we also found the superoxide radicals ( O2−) was considered to be the dominant active radical in the degradation of dye.

Mechanical coating followed by thermal oxidation in the atmosphere was used to prepare TiO 2 /SnO 2 composite coatings. The coatings were characterized by X-ray diffraction (XRD), scanning electronic spectroscopy (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and so on. Results show that continuous rutile TiO 2 coatings decorated with discrete SnO 2 particles were formed during thermal oxidation at the temperature range of 873–1073 K. Through the temperature range, a small quantity of SnO was formed. However, tiny amount of Ti 2 O 3 was formed only when oxidation temperature was 1073 K. The surface topography evolution of rutile TiO 2 crystals during the thermal oxidation and relevant mechanism was also examined. Equiaxed, rod, columnar and needle TiO 2 crystals with nanoscale were formed at temperatures from 873–1073 K. The topography evolution indicates that the diffusion of oxygen species into the formed rutile TiO 2 layer was predominant at 873 K. It favored the growth of equiaxed crystals in the tangent plane rather than radial direction of Al 2 O 3 ball substrate at the early stage of the thermal oxidation. However, the diffusion of Ti cations became prevailing compared with oxygen species at 1073 K. The reaction of Ti and oxygen species occurred at the external surface of the formed TiO 2 layer where rutile TiO 2 needles were formed. During thermal oxidation at 973 K, both the Ti cations and oxygen species were involved in the diffusion process and clusters of paired/parallel rutile TiO 2 nanorods were formed. The addition of metallic Sn remarkably affected the surface topography and the grain size of rutile TiO 2 crystals through regulating the diffusion of Ti cations and changing the local oxygen concentration surrounding Ti coatings. A proper additive amount refined the grains of rutile TiO 2 .