Bismuth organic frameworks exhibiting enhanced phosphorescence

Highly efficient electrochemical detection of H2O2 utilizing an innovative copper porphyrinic nanosheet decorated bismuth metal-organic framework modified electrode

The ability to detect hydrogen peroxide is important due to the presence in biological systems. Researchers are highly interested in developing efficient electrochemical hydrogen peroxide sensors. Metal-organic frameworks (MOFs) with their composites, an emerging class of porous materials, are ideal candidates for heterogeneous catalysts because of their versatile functionalities. Using a facile solvothermal reaction, we fabricated a 2D Cu-TCPP nanosheet uniformly grown on a 3D Bi-MOF. The process takes advantage of the large surface area and pore volume of the Bi-MOF while maintaining the crystallinity of Bi-BTC when Cu-TCPP is added to the surface. The sensor was fabricated by depositing the Bi-BTC-Cu-TCPP nanocomposites on a glassy carbon electrode to conduct electrochemical measurements such as cyclic voltammetry and electrochemical impedance spectroscopy. Finally, differential pulse voltammetry was utilized to investigate the effect of hydrogen peroxide on the electrochemical activity of Bi-BTC-Cu-TCPP deposited on a glassy carbon electrode. This electrode showed high electrochemical performance activity for the reduction of hydrogen peroxide. The sensor showed a linear response to H2O2 in the 10-120 μM concentration range, with a detection limit of 0.20 μM. The sensor was also stable and selective for H2O2 in the presence of other interfering species. This work demonstrates the potential of nanocomposite-based electrochemical sensors for sensitive and selective detection of H2O2. Besides, the modified electrode has many advantages, including remarkable catalytic activity, long-term stability, good reproducibility, and a good signal response during H2O2 reduction.

Efficient Europium Sensitization via Low-Level Doping in a 2-D Bismuth-Organic Coordination Polymer

A new bismuth-organic compound containing 1,10-phenanthroline (phen) and 2,5-pyridinedicarboxylic acid (PDC) was synthesized and structurally characterized by single-crystal X-ray diffraction. The structure consists of 2-D {Bi(phen)(HPDC)(PDC)}n sheets wherein the PDC ligands bridge metal centers via three unique bonding modes. The 2-D sheets are further connected through strong hydrogen-bonding interactions to form a 3-D supramolecular network. The parent compound displayed yellow photoluminescence in the solid state at room temperature. Doping studies were undertaken to incorporate Eu3+ into the structure, statistically replacing Bi3+ in small quantities (1, 5, and 10 mol % Eu3+ relative to Bi3+). All three compounds displayed characteristic Eu3+ emission, with total quantum yields as high as 16.0% and sensitization efficiencies between 0.21 and 0.37 depending on the Eu3+ doping percentage.