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Herein, three tritopic carboxylic acids were used to construct three Zr-MOFs, HIAM-4033, HIAM-4034, and HIAM-4035, to investigate the effect of carboxyl position on the MOF structures. The results showed that HIAM-4033 and HIAM-4034 possess (3,9)-c models with different underlying nets, whereas HIAM-4035 exhibits the same underlying net as UiO-68. Nanosized HIAM-4033 exhibits excellent sensitivity and selectivity for detecting aromatic acids, such as benzoic acid and 2-fluorobenzoic acid, compared with aliphatic acids and inorganic acids. This study offers new insights into achieving an organic linker directed structure evolution of Zr-MOFs, which might facilitate the discovery of unprecedented underlying nets. [ABSTRACT FROM AUTHOR]

The development of nanoscaled luminescent metal–organic frameworks (nano‐LMOFs) with organic linker‐based emission to explore their applications in sensing, bioimaging and photocatalysis is of great interest as material size and emission wavelength both have remarkable influence on their performances. However, there is lack of platforms that can systematically tune the emission and size of nano‐LMOFs with customized linker design. Herein two series of fcu‐ and csq‐type nano‐LMOFs, with precise size control in a broad range and emission colors from blue to near‐infrared, were prepared using 2,1,3‐benzothiadiazole and its derivative based ditopic‐ and tetratopic carboxylic acids as the emission sources. The modification of tetratopic carboxylic acids using OH and NH2 as the substituent groups not only induces significant emission bathochromic shift of the resultant MOFs, but also endows interesting features for their potential applications. As one example, we show that the non‐substituted and NH2‐substituted nano‐LMOFs exhibit turn‐off and turn‐on responses for highly selective and sensitive detection of tryptophan over other nineteen natural amino acids. This work sheds light on the rational construction of nano‐LMOFs with specific emission behaviours and sizes, which will undoubtedly facilitate their applications in related areas. [ABSTRACT FROM AUTHOR]

Development of cost‐effective and highly efficient oxygen evolution reaction (OER) electrocatalysts has become a vital project of renewable energy technologies. The OER is critical for a variety of electrochemical energy devices such as water electrolyzers, metal‐air batteries, CO2 reduction, and electrosynthesis of ammonia. Compared to extensively studied metal oxide catalysts, graphitized carbon catalysts have been newly emerged as promising OER catalysts especially in less corrosive alkaline media, due to their low cost, high electrical conductivity, unique physicochemical properties, and excellent electrocatalytic performances. In this review, we discussed recent advances in nanostructured carbon electrocatalysts. At first, metal‐free OER carbon electrocatalysts including single‐ and multi‐heteroatom doping and edge‐ and defect‐rich defects are introduced. Then, transition metal and heteroatom co‐doped nanocarbons are summarized including Co−N−C, Ni−N−C, and Fe‐N−C. In addition, carbon based hybrid electrocatalysts are highlighted, which include carbon based transition metal nitrides (TMNx), sulfides (TMSx), and selenides (TMSex), and phosphides (TMPx). Finally, current challenges and perspective for future research on carbon‐based OER catalysts are outlined. [ABSTRACT FROM AUTHOR]

Zirconium-based metal-organic frameworks (Zr-MOFs) have been extensively studied due to their very rich structural chemistry. The combination of nearly unlimited carboxylic acid-based linkers and Zr 6 clusters with multiple connectivities has led to diverse structures and specific properties of resultant Zr-MOFs. Herein, we demonstrate the successful use of reticular chemistry to construct two novel Zr-MOFs, HIAM-4040 and HIAM-4040-OH, with zfu topology. Based on a thorough structural analysis of (4,4)-connected lvt-type Zr-tetracarboxylate frameworks and a judicious linker design, we have obtained the first example of a Zr-pentacarboxylate framework featuring unprecedented 5-connected organic linkers and 5-connected Zr 6 clusters. Compared with HIAM-4040, a larger Stokes shift is achieved in HIAM-4040-OH via hydroxyl group induced excited-state intramolecular proton transfer (ESIPT). HIAM-4040-OH exhibits high chemical and thermal stability and is used for HClO detection in aqueous solution with excellent sensitivity and selectivity., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

Herein, we demonstrate the successful utilization of reticular chemistry as an excellent designing strategy for the deliberate construction of a zirconium-tetracarboxylate metal-organic framework (MOF) inspired by the Olympic rings. HIAM-4017, with an unprecedented (4,8)-c underlying net topology termed jcs , was developed via insightful reconstruction of the rings and judicious design of a nonsymmetric organic linker. HIAM-4017 exhibits high porosity and excellent chemical and thermal stability. Furthermore, excited-state intramolecular proton transfer (ESIPT) was achieved in an isoreticular MOF, HIAM-4018, with a large Stokes shift of 155 nm as a result of introducing the hydroxyl group to the linker skeleton to induce OH···N interactions. Such interactions were analyzed thoroughly by employing the time-dependent density functional theory (TD-DFT). Because of their good thermal and chemical stability, and strong luminescence, nanosized HIAM-4017 and HIAM-4018 were fabricated and used for Cr 2 O 7 2- detection. Both MOFs demonstrate excellent sensitivity and selectivity. This work represents a neat example of building structure- and property-specific MOFs guided by reticular chemistry.

Current Sn-based materials are ideal catalysts developed to drive the electrochemical conversion of CO 2 to formate, but competing proton reduction to hydrogen is an ever-present drain on catalytic selectivity. Herein, we report a reliable electrochemical exfoliation route, with the assistance of alternating voltage, for large-scale preparation of two-dimensional (2D) ultrathin tin monosulfide nanosheets (SnS NSs), which feature a large lateral size of 1.0 μm with a thickness of ∼5.0 nm. Systematic electrochemical studies demonstrated that the achieved SnS NSs exhibited an outstanding electrocatalytic activity towards the CO 2 reduction reaction (CO 2 RR) to the formate product, as evidenced by a considerable faradaic efficiency (F.E.) of 82.1%, a high partial current density of 18.9 mA cm -2 at -1.1 V, and a low Tafel slope of 180 mV dec -1 . Further, using an electrode prepared from the resulting SnS NSs by the particle transfer method, a remarkably high formate F.E. over 91% was achieved in a wide potential window. Such high performance renders the SnS NSs among the best reported tin sulfide-based CO 2 RR electrocatalysts. Theoretical calculations coupled with comprehensive experimental studies demonstrated that the synergistic effect between the ultrathin layered architecture and dominantly exposed (001) plane of SnS NSs accounted for the uniquely efficient catalytic activity for the CO 2 RR., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)