Photoluminescence, electrochemical behavior and photocatalytic activities of cobalt(II) coordination polymer nanostructures synthesized by sonochemical process

Sonochemical fabrication of Cu(II) and Zn(II) metal-organic framework films on metal substrates

In this article, we demonstrate a rapid and facile method for in-situ growth of metal-organic framework (MOF) films on Cu or Zn metal substrates by sonochemical techniques. The substrates were first treated with a strong oxidizing agent to convert the metal to the corresponding metal hydroxide. Ultrasonic irradiation provided the energy to drive the reaction between the metal ion sources and organic ligands. Four MOF films (Cu-BTC, Cu-BDC, ZIF-8 and MOF-5) were successfully fabricated by this approach. The produced films were characterized by scanning electron microscopy and X-ray diffraction analysis. The effects of organic ligand concentration and ultrasonic irradiation time on MOF film synthesis were also systematically investigated. The rapid and facile fabrication method presented in this article could serve a new route to grow MOF films on various gas sensor surfaces. Of the MOF films, ZIF-8 film was tested as a potential methane sensor.

Luminescence, electrochemical and photocatalytic properties of sub-micron nickel(II) and cobalt(II) coordination polymers synthesized by sonochemical process

Submicron structures of Ni^II/Co^II-based coordination polymers (CPs) [Ni(L1)(mip)·H₂O]_n (1) and {[Co(L2)(mip)]·0·.5H₂O}_n(2) (L1=1,6-bis(5,6-dimethylbenzimidazole)hexane, L2=1,6-bis(benzimidazole)hexane, H₂mip=5-methylisophthalic acid) were obtained by ultrasonic irradiation and structurally characterized by elemental analysis, powder X-ray diffraction and scanning electron microscopy. Structural analysis show that two CPs feature uninodal 3-connected 2D hcb layer, whilst CP 2 is further extended into a 3D complicated supramolecular network by C14-H14⋯O2 hydrogen bonds. Ultrasonic time and power influencing morphology of sub-micron sized CPs, were also discussed. Besides that, thermal stability, luminescence, electrochemical properties and photocatalytic activity of sub-micron sized 1 and 2 were presented in detail. Moreover, sub-micron sized 1 manifests the higher photocatalytic activity than sub-micron sized 2 for decomposition of methylene blue (MB) under UV irradiation.

Ultrasonic-promoted rapid preparation of PVC/TiO2-BSA nanocomposites: Characterization and photocatalytic degradation of methylene blue

In the present project in order to prevent agglomeration and better dispersion of TiO₂ nanoparticles (NPs) in the poly(vinyl chloride) (PVC) matrix, initially, the surface of TiO₂ NPs was covered by bovine serum albumin protein (BSA) via sonication method. Then, the TiO₂-BSA powders were embedded into the PVC matrix using ultrasonic irradiations. With mechanical and magnetic stirring homogenous mixture was not obtained. So sonication process was very essential and vital. Physical, chemical and structural properties of the samples were investigated with various tools. Morphology studies showed the well distribution of spherical TiO₂ NPs in the PVC matrix. TGA analysis showed that nanocomposites (NCs) have higher thermal stability than the pristine polymer. The photocatalytic activity tests by destroying the methylene blue dye on the pristine TiO₂ NPs, TiO₂-BSA NPs and PVC/TiO₂-BSA NC 6 wt% were examined. The results showed that the photocatalytic activity of TiO₂ NPs was reduced in the presence of BSA and PVC. It can be concluded that the TiO₂-BSA NPs and PVC/TiO₂-BSA NC 6 wt% have UV shielding properties and can protect film from degradation by UV.

A multifunctional Ni(ii) coordination polymer: synthesis, crystal structure and applications as a luminescent sensor, electrochemical probe, and photocatalyst

A new Ni(ii) complex containing 2,5-dichloroterephthalate and rigid bis(imidazole) ligands, which manifests multifunctional properties, has been synthesized and characterized.