Exploiting clean energy is essential for sustainable development and sunlight‐driven photocatalytic water splitting represents one of the most promising approaches toward this goal. Metal‐organic frameworks (MOFs) are competent photocatalysts owing to their tailorable functionality, well‐defined structure, and high porosity. Yet, the introduction of the unambiguous metal‐centered active site into MOFs is still challenging since framework motifs capable of anchoring metal ions firmly are lacking. Herein, the assembly using 1,4‐dicarboxylbenzene‐2,3‐dithiol (H2dcbdt) and Zr‐Oxo clusters to give a thiol‐functionalized UiO‐66 type framework, UiO‐66‐dcbdt, is reported. The thiocatechols on the struts are allowed to capture transition metal (TM) ions to generate UiO‐66‐dcbdt‐M (M  = Fe, Ni, Cu) with unambiguous metal‐thiocatecholate moieties for photocatalytic hydrogen evolution reaction (HER). UiO‐66‐dcbdt‐Cu is found the best catalyst exhibiting an HER rate of 4.18 mmol g−1 h−1 upon irradiation with photosensitizing Ru‐polypyridyl complex. To skip the use of the external sensitizer, UiO‐66‐dcbdt‐Cu is heterojunctioned with titanium dioxide (TiO2) and achieves an HER rate of 12.63 mmol g−1 h−1 (32.3 times that of primitive TiO2). This work represents the first example of MOF assembly employing H2dcbdt as the mere linker followed by chelation with TM ions and undoubtedly fuels the rational design of MOF photocatalysts bearing well‐defined active sites.

Using sunlight to manufacture hydrogen offers promising access to renewable clean energy. For this, low‐cost photocatalyst with effective light absorption and charge transfer are crucial, as current top‐performing systems often involve precious metals like Pd and Pt. An integrated organic–inorganic photocatalyst based on the cheap metals of iron and nickel are reported, wherein the metal ions form strong metal‐sulfur bonds with the organic linker molecules (2,5‐dimercapto‐1,4‐benzenedicarboxylic acid, H4DMBD) to generate 2D coordination sheets for promoting light absorption and charge transport. The 2D sheets are further modified through ionic metal‐carboxylate moieties to allow for functional flexibility. Thus, high‐surface‐area thin nanosheets of this 2D material, with an optimized Fe/Ni ratio (0.25:1.75), and in heterojunction with CdS nanosheet, achieve a stable photocatalytic hydrogen evolution rate of 12.15 µmol mg−1 h−1. This work synergizes coordination network design and nano‐assembly as a versatile platform for catalyzing hydrogen production and other sustainable processes.

Stimulus-responsive long persistent luminescence (LPL) materials have attracted wide attention due to their potential applications in information storage, anti-counterfeiting, optoelectronic devices, etc. However, LPL coordination polymers with room temperature afterglow transition characteristics have not been explored. Herein, mellitic acid and zinc ions were utilized to synthesize an acid–base stable coordination polymer (1) by an organic solvent-free hydrothermal method. 1 possesses a tightly stacked structure and exhibits dual-emission peaks with blue luminescence and blue-green afterglow. Upon exposure to heating, DMSO immersion, or vacuum, 1h, 1s, and 1v were obtained. The original blue luminescence changes to blue-green, while the afterglow turns yellow-green due to the loss of water molecules from the inner cavity. This is the first example of an LPL coordination polymer that can realize room temperature afterglow transition by dehydration operation. Moreover, the emission spectra of 1 can be recovered by exposing 1h, 1s, or 1v to water vapor, suggesting a reversible dehydration/hydration process. Experimental and density functional theory (DFT) results suggest that the fluorescence of 1 originates from the mixing of intra-ligand and ligand-to-metal charge transfer excited states. The triplet state from intersystem crossing is responsible for the long persistent luminescence of phosphorescence emission. The rational structural design along with the conceptual model of anti-counterfeiting and information encryption based on afterglow transition display the unique advantages of the LPL coordination polymer in realizing convenient multiple stimuli-responsive devices.

A robust and porous Ni-based metal–organic framework (MOF), NiL1, was assembled from Ni(II) ions and a dipyrazolate linker (L1 2–). A Ni(II)-anchored MOF catalyst Ni@NiL1-Sal has been successfully prepared by post-synthetic modification (PSM) condensation between NiL1 with salicylaldehyde, followed by chelation of Ni(II) ions by salicylaldimine as a secondary active site. Ni@NiL1-Sal with carbon black was found to exhibit enhanced electrocatalytic hydrogen evolution reaction (HER) performance (the smallest overpotential, 384 mV, and Tafel slope, 87 mV dec–1) when compared with primitive NiL1 and NiL1-Sal. Such improvement in HER highlights the creation of unambiguous secondary active sites as an avenue to the rational design of a functional MOF-based electrocatalyst.

Amongst the rapidly growing metal-organic frameworks (MOFs)-based sensors, the colorimetric MOF sensor for visual test of analytes is highly desired but rarely reported. Here, we developed such a colorimetric sensor...