Among the large family of metal–organic frameworks (MOFs), Zr-based MOFs, which exhibit rich structure types, outstanding stability, intriguing properties and functions, are foreseen as one of the most promising MOF materials for practical applications. Although this specific type of MOF is still in its early stage of development, significant progress has been made in recent years. Herein, advances in Zr-MOFs since 2008 are summarized and reviewed from three aspects: design and synthesis, structure, and applications. Four synthesis strategies implemented in building and/or modifying Zr-MOFs as well as their scale-up preparation under green and industrially feasible conditions are illustrated first. Zr-MOFs with various structural types are then classified and discussed in terms of different Zr-based secondary building units and organic ligands. Finally, applications of Zr-MOFs in catalysis, molecule adsorption and separation, drug delivery, and fluorescence sensing, and as porous carriers are highlighted. Such a review based on a specific type of MOF is expected to provide guidance for the in-depth investigation of MOFs towards practical applications.

Zr-based metal-organic frameworks: design, synthesis, structure, and applications.

Metal-organic frameworks (MOFs)-an emerging class of hybrid porous materials built from metal ions or clusters bridged by organic linkers-have attracted increasing attention in recent years. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, make them promising candidates as drug delivery hosts. Furthermore, scientists have made remarkable achievements in the field of nanomedical applications of MOFs, owing to their facile synthesis on the nanoscale and alternative functionalization via inclusion and surface chemistry. A brief introduction to the applications of MOFs in controlled drug/cargo delivery and cancer therapy that have been reported in recent years is provided here.

Metal-Organic Framework (MOF)-Based Drug/Cargo Delivery and Cancer Therapy.

Highly efficient removal of metal ion pollutants, such as toxic and nuclear waste-related metal ions, remains a serious task from the biological and environmental standpoint because of their harmful effects on human health and the environment. Recently, highly porous metal–organic frameworks (MOFs), with excellent chemical stability and abundant functional groups, have represented a new addition to the area of capturing various types of hazardous metal ion pollutants. This review focuses on recent progress in reported MOFs and MOF-based composites as superior adsorbents for the efficient removal of toxic and nuclear waste-related metal ions. Aspects related to the interaction mechanisms between metal ions and MOF-based materials are systematically summarized, including macroscopic batch experiments, microscopic spectroscopy analysis, and theoretical calculations. The adsorption properties of various MOF-based materials are assessed and compared with those of other widely used adsorbents. Finally, we propose our personal insights into future research opportunities and challenges in the hope of stimulating more researchers to engage in this new field of MOF-based materials for environmental pollution management.

Metal–organic framework-based materials: superior adsorbents for the capture of toxic and radioactive metal ions

The recent advancement of water stable metal–organic frameworks (MOFs) expands the application of this unique porous material. This review article aims at studying their applications in terms of five major areas: adsorption, membrane separation, sensing, catalysis, and proton conduction. These applications are either conducted in a water-containing environment or directly targeted on water treatment processes. The representative and significant studies in each area were comprehensively reviewed and discussed for perspectives, to serve as a reference for researchers working in related areas. At the end, a summary and future outlook on the applications of water stable MOFs are suggested as concluding remarks.

Applications of water stable metal–organic frameworks

Presented in this paper is a deep investigation into the defect chemistry of UiO-66 when synthesized in the presence of monocarboxylic acid modulators under the most commonly employed conditions. We unequivocally demonstrate that missing cluster defects are the predominant defect and that their concentration (and thus the porosity and composition of the material) can be tuned to a remarkable extent by altering the concentration and/or acidity of the modulator. Finally, we attempt to rationalize these observations by speculating on the underlying solution chemistry.

Defect Engineering: Tuning the Porosity and Composition of the Metal–Organic Framework UiO-66 via Modulated Synthesis

Though many efforts have been devoted to the adsorptive removal of hazardous materials of organophosphorus pesticides (OPs), it is still highly desirable to develop novel adsorbents with high adsorption capacities. In the current work, the removal of two representative OPs, glyphosate (GP) and glufosinate (GF), was investigated by the exceptionally stable Zr-based MOFs of UiO-67. The abundant Zr–OH groups, resulting from the missing-linker induced terminal hydroxyl groups and the inherent bridging ones in Zr–O clusters of UiO-67 particles, served as natural anchorages for efficient GP and GF capture in relation with their high affinity toward phosphoric groups in OPs. The correlation between the most significant parameters such as contact time, OPs concentration, adsorbent dose, pH, as well as ionic strength with the adsorption capacities was optimized, and the effects of these parameters on the removal efficiency of GP and GF from the polluted aqueous solution were investigated. The adsorption of GP on U...

Effective adsorption and enhanced removal of organophosphorus pesticides from aqueous solution by Zr-based MOFs of UiO-67.

Inherent anchorages in UiO-66 nanoparticles for efficient capture of alendronate and its mediated release

Defect creation in metal-organic frameworks for rapid and controllable decontamination of roxarsone from aqueous solution.


 Si-Cu composites composed of alternating Si-rich layer and Cu layers were obtained by two-potential pulse electrodeposition of -1900 and -1600 mV in 0.002 mol/L Cu(TfO)2-1 mol/L SiCl4(saturated)-[BMP]Tf2N ionic liquid at room temperature. The potential lasting time ratios for -1900 and -1600 mV changed from 0.5s/0.5s to 4s/0.5s, respectively. All of the Si-Cu composites showed an interconnected porous structure caused by the SiCl4 bubbles templates formation during electrodeposition. In particular, the Si-Cu 4-1 composite prepared at -1900 mV /-1600 mV for 2s/0.5s within 1 h, presented an interconnected mesoporous and macropore structure. And the Si-Cu 4-1 composite exhibited the best rate and cycle performances as anode of lithium-ion battery, with the initial capacity of 1589.2 mAh/g and capacity retention ratio of 72.6% after 1000 cycles at 1C. This is attributed to the lowest charge transfer resistance and fastest Li+ transfer ability due to the beneficial porosity-structure. This finding provides a new idea for the directly designing of interconnected porous material by pulse electrodeposition.

Pulse Electrodeposition of Interconnected Porous Si-Cu Composites as Anodes for Lithium-Ion Batteries

Platinum-rare earth metal (Pt-RE) nanoalloys are regarded as a potential high performance oxygen reduction reaction (ORR) catalyst. However, wet chemical synthesis of the nanoalloys is a crucial challenge because of the extremely high oxygen affinity of RE elements and the significantly different standard reduction potentials between Pt and RE. Here, this paper presents a molten-salt electrochemical synthetic strategy for the compositional-controlled preparation of platinum-neodymium (Pt-Nd) nanoalloy catalysts. Carbon-supported platinum-neodymium (Ptx Nd/C) nanoalloys, with distinct compositions of Pt5 Nd and Pt2 Nd, are obtained through molten-salt electrochemical deoxidation of platinum and neodymium oxide (Pt-Nd2 O3 ) precursors supported on carbon. The Ptx Nd/C nanoalloys, especially the Pt5 Nd/C exhibit a mass activity of 0.40 A mg-1 Pt and a specific activity of 1.41 mA cm-2 Pt at 0.9 V versus RHE, which are 3.1 and 7.1 times higher, respectively, than that of commercial Pt/C catalyst. More significantly, the Pt5 Nd/C catalyst is remarkably stable after undergoing 20 000 accelerated durability cycles. Furthermore, the density-functional-theory (DFT) calculations confirm that the ORR catalytic performance of Ptx Nd/C nanoalloys is enhanced by compressive strain effect of Pt overlayer, causing a suitable weakened binding energies of O* Δ E O ∗ $\Delta {E}_{{{\rm{O}}}^*}$ and Δ E OH ∗ $\Delta {E}_{{\rm{OH}}^*}$ .

Bing Li

Papers

Effective adsorption and enhanced removal of organophosphorus pesticides from aqueous solution by Zr-based MOFs of UiO-67.

Inherent anchorages in UiO-66 nanoparticles for efficient capture of alendronate and its mediated release

Defect creation in metal-organic frameworks for rapid and controllable decontamination of roxarsone from aqueous solution.

Pulse Electrodeposition of Interconnected Porous Si-Cu Composites as Anodes for Lithium-Ion Batteries

Molten-Salt Electrochemical Deoxidation Synthesis of Platinum-Neodymium Nanoalloy Catalysts for Oxygen Reduction Reaction.