A series of MOF/ZnO nanocomposites with different ZnO nanorod content were synthesized via a facile hydrothermal reaction. X-ray diffraction (XRD), UV-vis spectroscopy, field-emission scanning electron microscopy (FE-SEM), EDX, BET and FT-IR were employed to characterize the prepared samples. According to the UV-vis spectroscopy, the porphyrin center was filled with a Cu atom in Cu–TCPP. BET analysis shows that the surface area of Cu–TCPP MOF/ZnO nanorods composite was decreased compared to Cu–TCPP MOF. Therefore, ZnO nanorods covered the surface of the Cu–TCPP MOF crystals and distributed between the MOF nanosheets. Photocurrent measurements determined that MOF/ZnO nanocomposite with 15% of ZnO nanorod exhibited higher photoactivity under visible light irradiation. In the prepared nanocomposite, MOF sheets act as electron transport channels to efficiently separate the photogenerated charge carriers from ZnO nanorods. It is hoped that our current work could promote increased interest in designing the nanocomposites of one-dimensional semiconductor and two-dimensional MOFs for different photoassisted applications.

In this work, for the first time we report a highly specific and sensitive mercury ion (Hg²⁺) optical sensor (optode). The optode was prepared by recently synthesized nanocomposites, based on 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THPP) and graphene oxide nanosheets. In this nanocomposite, porphyrin was stabilized on the graphene oxide nanosheets. X-ray diffraction (XRD), UV-vis spectroscopy, field-emission scanning electron microscopy (FE-SEM) and FT-IR were employed to characterize the prepared nanocomposite. In the prepared optical chemical sensor, the formation of a Hg²⁺–ionophore complex between the mercury ions and the membrane phase, changes the UV-vis absorbance of the sensor. To improve the sensor response, various experimental parameters such as pH, concentration of THPP and graphene oxide nanosheets in the prepared nanocomposite were optimized. This optode exhibited a linear range of 6.0 × 10⁻⁹ to 6.0 × 10⁻⁵ mol L⁻¹ Hg(II) with a detection limit of 3.2 × 10⁻⁹ mol L⁻¹ and a response time of ∼210 s. It manifests advantages of low detection limit, fast response time, wide dynamic range, good reversibility, high reproducibility and also remarkable selectivity regarding the number of transition metals ions (i.e. Pb²⁺,Cr³⁺, Zn²⁺, Cd²⁺, Cu²⁺, Fe²⁺, and Ni²⁺). This optode was applied for determining Hg(II) ions in water samples.

Among the very few efforts for the preparation of stable pillared graphene nanostructures, there is no report of tin porphyrin intercalated between TiO₂–graphene (TG) nanosheets. Photocatalytic inactivation of bacteria mediated by TiO₂–graphene nanocomposites has been known as a green route, which has the potential to replace current antibiotic technology. In this work we intercalated a tin complex of tetrakis(4-carboxyphenyl)porphyrin (SnTCPP·Cl₂) between TiO₂–graphene nanosheets (TGSP) with 3% graphene content (TG (3%)). All materials were thoroughly characterized by Raman, XRD, DRS, BET, and SEM analysis. Subsequently, photoelectrochemical investigation determined the photoactivity of the prepared TGSP and the mechanism of the charge transfer in this compound. Furthermore, it has been demonstrated that the incorporation of SnTCPP between the TG nanosheets could successfully develop a new type of photocatalysis system. This photocatalyst is effective for the efficient photocatalytic inactivation of bacteria under visible light illumination.

The complexes [Co(Chel)(PBu₃)]ClO₄ · H₂O [Chel = BFE (bis(1,1,1-trifluoroacetylacetone)ethylenediimine) and BCE (bis(3-chloroacetylacetone)ethylenediimine)] and [Co(Chel)(PPh₃)]ClO₄ · H₂O, (Chel = BBE = bis(benzoylacetone)ethylenediimine and BFE), were synthesized and characterized. The spectroscopic and electrochemical properties of cobalt(III) derivatives of BAE (bis(acetylacetone)ethylenediimine) and related ligands have also been investigated. Electronic spectroscopic data indicate that the absorption between 600 and 760 nm in Co(III) BAE complexes is related to the lowest d–d transition. Axial ligands affect this transition and the reduction potential of Co(III) to Co(II) through σ-interaction with the dz² orbital. The π acceptor property of Schiff-base ligands increases in the order: