Hua Yao

Mixed matrix membranes incorporated with Ln-MOF for selective and sensitive detection of nitrofuran antibiotics based on inner filter effect

The detection of antibiotics is critical and challenging due to the pervasive use of antibiotics had inevitably brought some negative impacts on ecosystem and human health. Herein, we reported an anti-interfere ability enhanced luminescent sensor of lanthanide metal-organic framework (Ln-MOF) filled mixed matrix membranes (MMMs), which combining the processibility of poly(methyl methacrylate) (PMMA) polymer with Ln-MOF of {[Tb2(AIP)2(H2O)10]·(AIP)·4H2O}n (Tb-AIP, where AIP is 5-aminoisophthalate) fillers. The as-fabricated Tb-AIP MMMs are stable in water with a wide pH range and exhibit characteristic blue emission of Tb3+. Significantly, the Tb-AIP MMMs show highly selective and sensitive to nitrofuran antibiotics (NFAs) via inner filter effect (IFE), and yet remain unaffected not only by other common antibiotics but also by other types of analytes (metal ions and anions) that may coexist. The limits of detection for nitrofurantoin (NFT) and nitrofurazone (NFZ) are 0.30 and 0.35μM, respectively. As a proof of concept, the proposed MMMs sensor are demonstrated to be feasible for application in detecting NFAs in original water of Pearl River and bovine serum samples, the corresponding quenching constants and limits of detection are similar to their standard detections in an acceptable range. Furthermore, this MMMs sensor for NFAs detection was reversible after washing with deionized water. The luminescent Ln-MOF filled MMMs presented here provides a functional platform for simple yet useful in sensing of NFAs in environment and biology systems.

Electro-synthesized Ni coordination supermolecular-networks-coated exfoliated graphene composite materials for high-performance asymmetric supercapacitors

The high surface area of metal–organic frameworks (MOFs) has attracted considerable attention toward them as promising candidates for electrochemical capacitors, but their poor conductivity has limited their use in this field. Coordination supramolecular networks (CSNs) also exhibit a high specific surface area. However, they have been scarcely applied as electrode materials for supercapacitors yet. In the present study, a honeycomb-shaped Ni-pydc (pydc = pyridine-2,6-dicarboxylate) supermolecular-networks-coated electrochemically exfoliated graphene (Ni-pydc@EEG) composite was synthesized via a simple one-step electrochemical synthesis. The capacitance of the Ni-pydc@EEG composite increased sharply up to 835.3 F g−1 at 5 A g−1, while the pure Ni-pydc supermolecular networks could store only 158.7 F g−1 and the pure EEG could achieve only about 193.6 F g−1. This high capacitive performance could be attributed to the electrochemical synergistic effect between the redox active Ni-pydc and the EEG. To test for practical application, a small solid-state asymmetric device (Ni-pydc@EEG//EEG) was assembled and achieved a considerable energy density of 14.5 W h kg−1 at a high power density of 7500 W kg−1 and the ability to power a 2.5 W fan motor directly. The present work illustrates the magnificent potential of coordination supermolecular networks in electrochemical energy storage applications.

A nickel coordination supramolecular network synergized with nitrogen-doped graphene as an advanced cathode to significantly boost the rate capability and durability of supercapacitors

The strategy of developing new electrode materials, which integrate well with carbon materials or conducting polymers to form a robust synergistic composite, can distinctly boost the electrochemical performance of supercapacitors (SCs). In this study, a novel Ni coordination supramolecular network (CSN) of [Ni2(3,5-PDC)2·(H2O)8·(H2O)2]n (denoted as Ni-PDC, 3,5-PDC = 3,5-pyridinedicarboxylic acid) was successfully integrated with nitrogen-doped graphene (NG) via a one-step hydrothermal method, forming a superior composite electrode material of Ni-PDC@NG. The Ni-PDC@NG electrode showed a high specific capacitance of 735 F g−1 at a current density of 1 A g−1 and an outstanding cycling stability (85.3% capacitance retention after 14 000 cycles); furthermore, it also maintained a good rate capability by exhibiting a capacitance retention of 53% even at a high current density of 40 A g−1. Significantly, a SC device was assembled with the Ni-PDC@NG electrode as the cathode and an activated carbon electrode as the anode, which not only exhibited a high energy density of 21.7 W h kg−1 at a power density of 801 W kg−1, but also retained 45.2% of its initial energy density even at a high power density of 16 036 W kg−1. Besides, this as-fabricated device exhibited excellent long-term durability with 97.9% capacitance retention after 6000 cycles.