Metal-organic frameworks (MOFs) have received increasing attention as promising electrode materials in supercapacitors (SCs). Yet poor conductivity in most MOFs largely thwarts their capacitance and/or rate performance. In this work, an effective strategy was developed to reduce the bulk electric resistance of MOFs by interweaving MOF crystals with polyaniline (PANI) chains that are electrochemically deposited on MOFs. Specifically we synthesized cobalt-based MOF crystals (ZIF-67) onto carbon cloth (CC) and further electrically deposited PANI to give a flexible conductive porous electrode (noted as PANI-ZIF-67-CC) without altering the underlying structure of the MOF. Electrochemical studies showed that the PANI-ZIF-67-CC exhibits an extraordinary areal capacitance of 2146 mF cm(-2) at 10 mV s(-1). A symmetric flexible solid-state supercapacitor was also assembled and tested. This strategy may shed light on designing new MOF-based supercapacitors and other electrochemical devices.

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A powerful roll-to-roll hot-pressing strategy for mass production of metal-organic framework (MOF)-based filters (MOFilters) using various MOF systems with ranges of substrates is presented. Thus-obtained MOFilters show superior particulate matter removal efficiency under desired working temperatures. Such versatile MOFilters can be scaled up and purposely designed, which endows MOFilters with great potentials in both residential and industrial pollution control.

Radical anions of electron-deficient systems are widely used, but are easily reoxidized upon exposure to air. Therefore, the stabilization of radical anions under ambient conditions is of great significance, but still remains a scientific challenge. Herein, perylenediimide is employed to prepare a crystalline metal-organic framework for stabilizing radical anions without extensive chemical modification. The porous, three-dimensional framework of perylenediimide can trap electron donors such as amine vapors and produce radical anions in-situ through photo-induced electron transfer. The radical anions are protected against quenching by shielding effect in air and remain unobstructed in air for at least a month. Because of the high yield and stability of the radical anions, which are the basis for near-infrared photothermal conversion, the framework shows high near-infrared photothermal conversion efficiency (η = 52.3%). The work provides an efficient and simple method towards ambient stable radical anions and affords a promising material for photothermal therapy.

The design of highly stable, selective and efficient electrocatalysts for CO2 reduction reaction is desirable while largely unmet. In this work, a series of precisely designed polyoxometalate-metalloporphyrin organic frameworks are developed. Noted that the integration of {ε-PMo8VMo4VIO40Zn4} cluster and metalloporphyrin endows these polyoxometalate-metalloporphyrin organic frameworks greatly advantages in terms of electron collecting and donating, electron migration and electrocatalytic active component in the CO2 reduction reaction. Thus-obtained catalysts finally present excellent performances and the mechanisms of catalysis processes are discussed and revealed by density functional theory calculations. Most importantly, Co-PMOF exhibits remarkable faradaic efficiency ( > 94%) over a wide potential range (−0.8 to −1.0 V). Its best faradaic efficiency can reach up to 99% (highest in reported metal-organic frameworks) and it exhibits a high turnover frequency of 1656 h−1 and excellent catalysis stability ( > 36 h).

Metal-organic frameworks (MOFs) are a promising class of nanoporous polymeric materials. However, the processing of such fragile crystalline powders into desired shapes for further applications is often difficult. A photoinduced postsynthetic polymerization (PSP) strategy was now employed to covalently link MOF crystals by flexible polymer chains, thus endowing the MOF powders with processability and flexibility. Nanosized UiO-66-NH2 was first functionalized with polymerizable functional groups, and its subsequent copolymerization with monomers was easily induced by UV light under solvent-free and mild conditions. Because of the improved interaction between MOF particles and polymer chains, the resulting stand-alone and elastic MOF-based PSP-derived membranes possess crack-free and uniform structures and outstanding separation capabilities for Cr(VI) ions from water.

Mimicking natural photosynthesis to convert CO2 with H2O into value-added fuels achieving overall reaction is a promising way to reduce the atmospheric CO2 level. Casting the catalyst of two or more catalytic sites with rapid electron transfer and interaction may be an effective strategy for coupling photocatalytic CO2 reduction and H2O oxidation. Herein, based on the MOF ∪ COF collaboration, we have carefully designed and synthesized a crystalline hetero-metallic cluster catalyst denoted MCOF-Ti6Cu3 with spatial separation and functional cooperation between oxidative and reductive clusters. It utilizes dynamic covalent bonds between clusters to promote photo-induced charge separation and transfer efficiency, to drive both the photocatalytic oxidative and reductive reactions. MCOF-Ti6Cu3 exhibits fine activity in the conversion of CO2 with water into HCOOH (169.8 μmol g−1h−1). Remarkably, experiments and theoretical calculations reveal that photo-excited electrons are transferred from Ti to Cu, indicating that the Cu cluster is the catalytic reduction center.

Efficient conversion of carbon dioxide (CO2) into value-added products is essential for clean energy research. Design of stable, selective, and powerful electrocatalysts for CO2 reduction reaction (CO2RR) is highly desirable yet largely unmet. In this work, a series of metalloporphyrin-tetrathiafulvalene based covalent organic frameworks (M-TTCOFs) are designed. Tetrathiafulvalene, serving as electron donator or carrier, can construct an oriented electron transmission pathway with metalloporphyrin. Thus-obtained M-TTCOFs can serve as electrocatalysts with high FECO (91.3%, −0.7 V) and possess high cycling stability (>40 h). In addition, after exfoliation, the FECO value of Co-TTCOF nanosheets (~5 nm) is higher than 90% in a wide potential range from −0.6 to −0.9 V and the maximum FECO can reach up to almost 100% (99.7%, −0.8 V). The electrocatalytic CO2RR mechanisms are discussed and revealed by density functional theory calculations. This work paves a new way in exploring porous crystalline materials in electrocatalytic CO2RR.