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Rapid and accurate determination of biomarkers of human poisoning in real urine is of great significance for the assessment of health status. Herein, a luminescent urea-functionalized metal-organic framework (MOF), {[Cd(L) 0.5 (bpbix)]· x (solv)} n (1) (H 4 L = 5,5'-(((naphthalene-1,5-diylbis(azanediyl))bis(carbonyl))bis(azanediyl))diisophthalic acid; bpbix = 4,4'-bis((1 H -imidazol-1-yl)methyl)biphenyl), has been successfully synthesized, and exhibits good stability in aqueous solutions in the normal urinary pH range and real urine. Complex 1 can serve as a dual-responsive luminescent biosensor for the detection of diphenyl phosphate (DPP) and hippuric acid (HA) as biomarkers of flame retardant triphenyl phosphate and toluene poisoning, and shows the advantages of high sensitivity, rapid response, good anti-interference capability, and reversibility. More significantly, complex 1 is successfully applied to the sensitive and accurate detection of DPP and HA in real urine with satisfactory recoveries. This work presents a dual-responsive luminescent MOF-based biosensor for simple, rapid, accurate, and reversible determination of urinary DPP and HA, which has promising application potential for the diagnosis of diseases related to triphenyl phosphate and toluene poisoning.

The preparation of ultra-small and well-dispersed metal nanoparticles (NPs) is of great importance for promoting oxygen reduction. Here, a metal (Fe and Zn) NP (7 nm) based catalyst derived from a Zn-based metal–organic framework was obtained by a vapor adsorption strategy, demonstrating a high half-wave potential (0.868 V) and power density (196 mW cm−2). [ABSTRACT FROM AUTHOR]

The production of metal–organic framework (MOF) nanoplates with well‐defined geometric morphology is remarkable for expanding their applications. Herein, the cobalt‐based MOF nanoplates with hexagonal channels from a layer‐pillared MOF are accomplished, via a molecular scalpel strategy, utilizing monodentate pyridine to replace the bidentate 4,4′‐bipyridine. The morphology can be modified from nanorods to nanoplates with controllable thickness tuned by the amounts of pyridine. Succeeding carbonization treatment transforms the MOF nanoplates into Co particles homogeneously encapsulated in the nitrogen‐doped carbon layers. The prepared catalyst with a unique platelike morphology displays a high half‐wave potential of 0.88 V in oxygen reduction reaction. When used in primary Zn−air batteries, it delivers a high peak power density of 280 mW cm−2. This work clarifies the structure‐morphology‐reactivity connection of MOF nanoplates. [ABSTRACT FROM AUTHOR]

Hollow CoFe alloy coupled with N-doped Ketjen Black (CoFe@NC/KB-800) is prepared by pyrolysis of a novel Fe-glu coated {Co(L)(BPDC)} n. Benefiting from micro-/meso-/macropore structure, ultra-high specific surface area (1318.8 m2 g−1), and enriched active sites (hollow CoFe alloy and N-doped porous carbon), CoFe@NC/KB-800 exhibits excellent ORR/OER activity with a low △ E of 0.77 V. Liquid and all-solid-state ZABs equipped with CoFe@NC/KB-800 display huge potential in portable devices. [Display omitted] • Novel nitrogenous {Co(L)(BPDC)} n is prepared. • Hollow CoFe alloys can shorten the mass transport pathways. • N-doped Ketjen Black can enhance stability and electrical conductivity. • CoFe@NC/KB-800-based ZAB exhibits a low voltage gap of 0.65 V. • DFT calculations indicate the synergism of CoFe@NC sites. Rational design of highly effcient bifunctional oxygen catalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a significant challenge for rechargeable Zn–air battery (ZAB). Herein, a newly developed hybrid catalyst (denoted as CoFe@NC/KB-800) consisting of hollow CoFe alloy and nitrogen-doped Ketjen Black is synthesized by pyrolysis of a novel Fe-glucosamine coated cobalt-based metal–organic framework. By virtue of ultra-high specific surface area of 1318.8 m2 g−1 and micro-/meso-/macropore structure, the optimal CoFe@NC/KB-800 catalyst exhibits a low reversible oxygen overpotential (Δ E) of 0.77 V between ORR and OER. Density functional theory (DFT) calculations validate that the superior catalytic activity is ascribed to synergistic CoFe@NC structure. Impressively, liquid ZAB catalyzed by CoFe@NC/KB-800 displays a high peak power density of 160 mW cm−2 and a low voltage gap of 0.65 V after 600 cycles. Three all-solid-state ZABs in series can successfully light LED (~2.2 V), displaying tremendous potentials in portable devices. [ABSTRACT FROM AUTHOR]

Rational design of non-noble metal-based bifunctional electrocatalysts for hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) is still a challenge in water splitting. Herein, a MOF-on-MOF (MOF = metal-organic framework) strategy is developed to obtain trimetal-based nitrogen-doped carbon nanotubes arrays loaded on nickel foams (denoted as FeNiCo@NC/NF). Benefiting from the superior compositional and structural feature, FeNiCo@NC/NF self-supported electrodes exhibit excellent bifunctional HER and OER activity with a low overpotential of 145 and 245 mV at 10 mA cm−2. When simultaneously used as cathode and anode for water splitting, it only requires 1.61 V to achieve 10 mA cm−2 and even outperforms the benchmark electrode couple of Pt/C||RuO 2 at higher current densities. Studies discover that trimetallic FeNiCo nanoparticles can provide more synergetic metal active sites, interconnected N-doped carbon nanotubes arrays can offer more effective electron transports channels, and conductive Ni foam substrate can reduce the internal impedance of the material. Density functional theory (DFT) calculations also demonstrate that FeNiCo@NC/NF electrode possesses a favorable Gibbs free energy of hydrogen adsorption (ΔG H*) value of −0.13 eV, which is benefit for its superior HER activity. Overall, our work reports an efficient self-supported electrode for hydrogen/oxygen evolution reactions and water splitting. • Synergistic effect among trimetals and N-dopants enhances HER/OER activities. • N-CNTs could offer more effective electron transports channels. • Hierarchical structure ensures super-fast evolution and escape of H 2 and O 2. • Without polymer binder reduces the internal impedance of the material. • ΔG H* = −0.13 eV further manifests their superior HER activity. [ABSTRACT FROM AUTHOR]