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Global clean energy demands can be effectively addressed using the promising approach of hydrogen energy generation combined with less energy consumption. Hydrogen can be generated, and urea-rich wastewater pollution can be mitigated in a low-energy manner using the urea oxidation reaction (UOR). This paper seeks to assemble a unique electrocatalyst of a pristine 2D MOF, [Co(HBTC)(DMF)]n(Co-MUM-3), from 1,3,5-benzenetricarboxylate (BTC) to oxidize urea in simulated seawater. Ni foam (NF)-based working electrodes were fabricated by incorporating a series of heterometallic CuCo-MUM-3 frameworks (Cu0.1Co0.9-MUM-3, Cu0.2Co0.8-MUM-3, Cu0.3Co0.7-MUM-3, and Cu0.4Co0.6-MUM-3), after which their application in the urea oxidation reaction was examined. A very low required overpotential [1.26 V vs reversible hydrogen electrode (RHE) in 1 M KOH + 0.5 M NaCl (simulated seawater) + 0.33 M urea] and a Tafel slope of 112 mV dec–1could be observed for the Cu0.3Co0.7-MUM-3 electrocatalyst, ensuring the achievement of urea electro-oxidation and hydrogen evolution reactions at a corresponding 10 mA cm–2electrocatalytic current density. A relatively lower overpotential will be evident compared to other reported pristine MOFs, outperforming the commercial catalyst RuO2(1.41 V at 10 mA cm–2, 131 mV dec–1) and ensuring considerable stability at significantly high current densities for a minimum of 72 h.

Defect engineering is an extremely effective strategy for modifying metal–organic frameworks (MOFs), which can break through the application limitations of traditional MOFs and enhance their functionality. Herein, we report a highly robust nanoporous thulium(III)–organic framework, {[Tm2(BDCP)(H2O)5](NO3)·3DMF·2H2O}n(NUC-105), with [Tm(COO)2(H2O)]nchains and [Tm2(COO)4(H2O)8] dinuclears as metal nodes and 2,6-bis(2,4-dicarboxylphenyl)-4-(4-carboxylphenyl)pyridine (BDCP) linkers. In NUC-105, each of the four chains of [Tm(COO)2]nand the two rows of [Tm2(COO)4(H2O)8] units is unified by the organic skeleton, resulting in a rectangular nanochannel with dimensions of 15.35 Å × 11.29 Å, which leads to a void volume of 50%. It is worth mentioning that the [Tm2(COO)4(H2O)8] cluster is very rare in terms of its higher level of associated water molecules, implying that the activated host framework can serve as a strong Lewis acid. NUC-105aexhibited great heterogeneous catalytic performance for CO2cycloaddition with epoxides under the reaction conditions (0.60 mol % NUC-105a, 5.0 mol % n-Bu4NBr, 65 °C, 5 h), ensuring exclusive selectivity and high conversion rates. In addition, NUC-105a’s strong catalytic impact on the Knoevenagel condensation of aldehydes and malononitrile can be attributed to the collaboration between the drastically unsaturated Lewis acidic Tm3+centers and Lewis basic pyridine groups.

A variety of new inorganic and organic materials have emerged to advance laser technologies and optical engineering. A rational design approach can contribute significantly to fabricating nonlinear optically active metal–organic frameworks (MOFs) by considering the underlying structure–property linkage. Here, it has been embarked on a study of novel samarium(III) MOF, ([Sm2(ata)3(DMF)4]·DMF (ata2–: 2-aminoterephthalate), abbreviated as NH2-Sm-MUM-4) with enhanced nonlinear optical (NLO) properties. The crystal structure of this MOF represents a 6-connected framework with a pcutopology and distinctive characteristics, including open metal sites, free amine groups, and great stability, making it suitable for third-order NLO activity. The nonlinear index of refraction (n2) revealed the self-focusing impacts of NH2-Sm-MUM-4 at different incident intensities. The highest value of n2and β related to 10 mw power of incident intensity are 5.15 cm2/W and 2.65 cm/W, respectively. As far as the authors know, this is the first study examining the potential systematic structural–property associations in Sm-MOFs considering improved third-order NLO properties.