Electrochemical Synthesis and Electrocatalytic Oxygen-Evolution Performance of Two-Dimensional NiCo-BPDC Materials.

Metal-organic frameworks (MOFs) have been widely studied as electrocatalysts, and the research strategy to improve their electrocatalytic oxygen evolution reaction (OER) performance is to modify their structure. In this paper, two-dimensional bimetallic MOFs were constructed to improve electrocatalytic OER performance. Using a mild electrochemical method with Ni and Co as metal sources and 4, 4 '-biphenyl dicarboxylic acid (H2 BPDC) as ligand, two-dimensional NiCo-BPDC was synthesized and then deposited on a carbon cloth electrode. The results show that NiCo-BPDC/CC possessed a low overpotential of 356 mV at a current density of 20 mA cm-2 with a small Tafel slope of 86 mV dec-1 in 1.0 M KOH solution. The two-dimensional NiCo-BPDC exhibits excellent electrocatalytic OER performance because the coordination of Ni and Co in the material and the interaction of the two-dimensional materials provide a large electrochemically active surface area and expose more metal active sites for OER, thus improving the reaction efficiency and indicating NiCo-BPDC as potential OER electrocatalyst.

Continuous and Rapid Synthesis of UiO-67 by Electrochemical Methods for the Electrochemical Detection of Hydroquinone.

Continuous and rapid synthesis of UiO-67 under mild conditions has been achieved by electrochemical methods for the first time. In the reaction system, a zirconium sheet was utilized as electrodes and a metal source for the assembly of UiO-67. High-crystalline UiO-67 with a regular tetrahedral morphology of around 1 µm was obtained within 1.5 h under the optimized solvent composition, voltage, and temperature conditions. This electrochemical synthetic method of UiO-67 in our work overcomes the shortcomings of high temperature and pressure of a traditional solvothermal method, which proposes new ideas for the large-scale and rapid synthesis of UiO-67. The UiO-67 synthesized by an electrochemical method was prepared as a UiO-67-carbon paste electrode (CPE), which exhibited a linear response to hydroquinone (HQ) in the range of 5-300 µM with a detection limit of 3.6 × 10-9 M (S/N = 3), for the electrochemical detection of HQ. It was confirmed that UiO-67-CPE possessed excellent reusability and antiinterference ability for the detection of HQ, and its detection ability even did not change after standing for 3 months. We further tried to apply UiO-67-CPE to the practical determination of HQ in tap water and river water samples, and the results proved that the recovery rate is 97.9-104.7% in real samples.

Rapid and Low-Cost Electrochemical Synthesis of UiO-66-NH2 with Enhanced Fluorescence Detection Performance.

Rapid and low-cost synthesis of metal-organic frameworks (MOFs) are very meaningful for their future practical application. In the present study, a Zr-based ultrastable MOF, UiO-66-NH2, was successfully synthesized by electrochemical method using metal Zr as the metal source at room temperature and atmospheric pressure. The effects of the reaction conditions, including the ratio of solvent (electrolyte), the applied voltage and different reaction time, on the crystallinity, morphology, and synthesis rate of the product were fully investigated. The results confirm that electrochemically synthesized UiO-66-NH2 under the optimized condition possesses apparent merits such as high crystallinity, uniform morphology and high porosity. Moreover, the electrochemical synthesis method of UiO-66-NH2 is promising for the large-scale and economical synthesis of nanoscale product to gramme degree. Interestingly, the resulting UiO-66-NH2 synthesized by this electrochemical method exhibits more excellent performance for the fluorescence detection of Fe3+ ions in water (detection limit of 10-8 mol/L) than that of the material prepared by solvothermal method.

Rapid and Large-Scale Synthesis of IRMOF-3 by Electrochemistry Method with Enhanced Fluorescence Detection Performance for TNP.

Rapid and large-scale synthesis of metal-organic frameworks (MOFs) materials is of great significance for their practical applications. For the first time, we have electrochemically synthesized IRMOF-3 at room temperature by applying a voltage to a zinc electrode immersed in electrolyte containing 2-aminoterephthalic acid (NH2-H2BDC). The reaction conditions, including the ratio of solvent (electrolyte), the applied voltage, and different reaction times, were investigated and optimized. The degree of crystallinity and nanomorphology of the synthesized IRMOF-3 can be controlled by changing the reaction conditions. More importantly, we demonstrated that the electrochemical synthesis strategy can rapidly obtain nanoscale IRMOF-3 with high crystallinity on a gram scale. In addition, in comparison with the product of solvothermal synthesis, the electrochemically synthesized nanoscale IRMOF-3 exhibits improved fluorescent detection ability to 2,4,6-trinitrophenol (TNP) with a detection limit of about 0.1 ppm.

Postsynthetic Modification of ZIF-90 for Potential Targeted Codelivery of Two Anticancer Drugs.

Combination therapy has been regarded as a promising strategy for cancer treatment due to the enhanced anticancer efficacy achieved by blocking multiple drug resistance pathways. In this work, a drug carrier based on nanoscale ZIF-90 for the codelivery of two anticancer drugs has been synthesized by covalently attaching doxorubicin (DOX) to the surface of ZIF-90 via Schiff base reaction of amino group in DOX and aldehyde group of imidazole-2-carboxaldehyde (ICA) ligand and encapsulating 5-fluorouracil (5-FU) into the pores of the framework. The results of drug loading measurements show that the loading amount of drugs was estimated as high as 36.35 and 11-13.5 wt % for 5-FU and DOX, respectively. Moreover, we demonstrated that the carrier had the potential of cancer-targeted delivery of drugs for the collapse of framework under the pH environment around cancer cells and subsequently releasing drugs. Drug release at pH 5.5, imitating the environment of tumor, can reach over 95%, and the release time is less 16 h, meaning a more effective and faster release of drugs around tumoral cells than that in a normal environment. This is the first report for cancer-targeted codelivery of two different chemical drugs based on nanoscale metal-organic frameworks (NMOFs).