Abstract The oriented assembly of heterostructures at the boundaries of nanosheets offers substantial advantages over surface‐based heterostructures, owing to their enhanced built‐in electric fields, more efficient charge transport pathways, and greater accessibility of active sites. However, the precise design of boundary‐engineered heterojunctions remains challenging due to the complex process and unclear growth mechanism. Herein, the development of a boundary‐engineered heterojunction is reported by loading Ce‐Ni(OH) 2 onto the edges of Co‐MOF nanosheets through a regulated electrodeposition process, driven by boundary effect induced by Ce single‐atom doping. A systematic investigation is conducted to explore the effects of boundary effect on the construction of boundary‐engineered heterojunctions. The Co‐MOF/Ce‐Ni(OH) 2 @CC exhibits superior oxygen evolution reaction (OER) activity, achieving an ultra‐low overpotential of 140 mV at 10 mA cm −2 in 1 M KOH. Enhanced by density functional theory (DFT) calculations and in situ Raman characterization, the Ce single‐atom acts as an electron reservoir for Ni sites via the Ce─O─Ni chain during OER, thereby facilitating electron transfer from Ni(OH) 2 to Co‐MOF. This promotes the formation of NiOOH and boosts the OER activity. Furthermore, the Kelvin probe force microscopy (KPFM) analysis reveals that the incorporation of Ce intensifies the local electric field at the nanosheet boundary, and facilitates the deposition of Ni(OH) 2 on the edges, thereby promoting the formation of boundary‐engineered heterojunctions.

Abstract Copper nanoclusters with stable compositions and precise structures have long been sought after, as they possess properties that are absent in gold and silver counterparts. However, the creation of copper nanoclusters with novel compositions, structures, and functionalities remains largely unexplored in the literature. In this study, we demonstrate that selenide doping is an effective method for fabricating stable copper nanostructures through controlled synthesis and structure determination of a copper–selenide nanocluster. The nanocluster of [Cu 32 Se 7 (BnSe) 18 (PPh 3 ) 6 ] + (denoted as Cu 32 Se 7 , Bn is benzyl) has been prepared by reducing copper salts in the presence of organic diselenides. The atomic structure of the Cu 32 Se 7 cluster, accurately determined through single‐crystal X‐ray diffraction, reveals a core–shell arrangement of Cu 20 Se 7 @Cu 12 (BnSe) 18 (PPh 3 ) 6 , where Se 2− anions are well dispersed in the Cu 20 framework. Notably, this cluster represents a rare example of copper–selenide semiconductor nanoclusters. Experimental and theoretical analysis shows strong interactions between Se ligands and metal atoms, resulting in high stability of the Cu 32 Se 7 cluster. Furthermore, the cluster exhibits excellent catalytic performance in the hydroboration reaction of alkynes, producing a range of vinylboron compounds with adjustable structures and functions. Importantly, the cluster undergoes no structural or nuclearity changes during the reaction, as confirmed by extended X‐ray absorption fine structure and X‐ray photoelectron spectroscopy studies. This study not only presents a molecular cluster model highlighting the effectiveness of selenide dopants in fabricating new copper nanostructures but also paves the way for utilizing stable copper nanoclusters in diverse and exciting areas beyond catalysis.

Metal-organic framework (MOF) glasses are an emerging class of glasses which complement traditional inorganic, organic and metallic counterparts due to their hybrid nature. Although a few zeolitic imidazolate frameworks have been made into glasses, how to melt and quench the largest subclass of MOFs, metal carboxylate frameworks, into glasses remains challenging. Here, we develop a strategy by grafting the zwitterions on the carboxylate ligands and incorporating organic acids in the framework channels to enable the glass formation. The charge delocalization of zwitterion-acid subsystem and the densely filled channels facilitate the coordination bonding mismatch and thus reduce the melting temperature. Following melt-quenching realizes the glass formation of a family of carboxylate MOFs (UiO-67, UiO-68 and DUT-5), which are usually believed to be un-meltable. Our work opens up an avenue for melt-quenching porous molecular solids into glasses.

Main group metals are routinely considered as catalytically inactive. In this work, we for the first time prepared a p-block tin single atom catalyst (Sn SA –NC) with Sn–N 4 active site for effectively improving the lithium–sulfur battery performance.

Abstract Electrochemical nitrate (NO 3 − ) reduction to ammonia (NH 3 ) under ambient conditions is promising to promote the artificial nitrogen cycling. Despite the development of transition metal‐based catalysts, their incident in situ electrochemical reconstruction always leads to the ambiguity of veritable active sites and reaction mechanisms. In this work, we report an approach to encapsulate Ni@Ni 2 P particles with cationic Ni vacancies in hollow N‐doped carbon nanofibers (designated Ni@Ni 2‐ x P@N‐CNFs) for electrocatalytic NO 3 − reduction to NH 3 and have investigated their surface reconstruction and reaction mechanisms using various in situ electrochemical characterizations and theoretical calculations. Specially, the regulation of cationic Ni vacancy concentration in the three defective Ni@Ni 2‐ x P@N‐CNFs catalysts leads to the 3.92‐fold NH 3 yield rate difference at −0.2 V versus RHE. During the electrocatalytic reaction process, new amorphous Ni(OH) 2 and NiOOH species form on the surface of Ni@Ni 2‐ x P@N‐CNFs and the stable amorphous Ni(OH) 2 species benefits the generation of more active hydrogen (*H) for hydrogenation with NO 3 − . This is further verified by the different reaction rate‐determining steps on the pristine and reconstructed defective catalysts. Integration of the optimized defective catalyst as cathode into a stable aqueous Zn–NO 3 –battery provides high power density and Faraday efficiency for NH 3 .

Abstract Three metal covalent organic frameworks (MCOFs), namely RuCOF‐ETTA, RuCOF‐TPB and RuCOF‐ETTBA, were synthesized by incorporating the photosensitive Ru II tris(2,2′‐bipyridine) unit into the skeleton. Interestingly, each RuCOF contains three isostructural covalent organic frameworks that interlock together with the Ru II centers serving as point of registry. The covalently linked network coupling with uniformly distributed Ru II units allowed the RuCOFs to exhibit superior chemical stability, strong light‐harvesting ability, and high photocatalytic activity toward hydrogen evolution (20 308 μmol g −1 h −1 ). This work illustrates the potential of developing versatile MCOFs‐based photocatalysts from functionalized metal complex building unit and further enriches the MCOFs family.

Abstract Dynamically self‐adaptive optimizing the local microenvironment of Ru─O bonds to enhance the adsorption of the *H is crucial for the efficient catalytic process. However, the limited regulatory strategies are unable to spontaneously control the Ru─O reconstruction process, thereby preventing the competitive adsorption of key intermediates at the catalytic active sites. Herein, an electronic asymmetry engineering is proposed by Ru single atoms coordinate with P and O atoms to create a local asymmetric O─Ru─P moiety, achieving dynamic optimization of Ru─O bond under the potential driven state during the HER process. The resultant Ru SA ─CoP electrocatalyst exhibits remarkable overpotentials of 15, 38, and 36 mV at a current density of 10 mA cm −2 in alkaline, acidic, and neutral media. Advanced in‐situ characterization reveals that the asymmetric O─Ru─P sites can modulate electron redistribution under the potential‐driven conditions, which achieves dynamic optimization of Ru─O bonds and strengthens Ru─H bonding interactions. More importantly, when the voltage is removed, the Ru─O bond is clearly observed again, which reveals the dynamic adaptation of Ru─O coordination during the reaction process. This work reveals the influence of the dynamic coordination evolution and structural adaptability of electrocatalysts on catalytic performance, providing valuable ideas for the design and synthesis of efficient electrocatalysts.

Abstract Recently, to achieve the goal of increasing both crop yield and water/nitrogen use efficiency with a better irrigation regime is a major challenge in semi-arid areas. In this study, we presented a two seasonal-field experiment that considers irrigation regimes, i.e., no irrigation (W0), irrigated in jointing (W1), both in jointing and flowering (W2) after the re-greening, and varieties (S086; J22) to compare the response of the sensitivity of wheat leaf physiological indicators, yield, water/N use efficiency and soil water consumption to irrigation regimes. The results showed that the WUE, IWUE and soil water-holding consumption (SWC) decreased with the increase in amount of irrigation. Additionally, 45.5% of the excessive irrigation water input did not promote wheat yield (W1 vs. W2). The degree of SWC in the 0–120 cm soil layer was highly related to wheat growth. S086 was beneficial for the usage of SWC under a low amount of irrigation. As well, irrigation positively affected the activities of superoxide dismutase (SOD) and catalase (CAT) in the flag leaf (P<0.05) during crop yield production. A decrease of irrigation helped to increase the concentrations of SS and Pro and decrease of amount of MDA for S086. Thus, a high yield of S086 was found under deficit irrigation (W1, a 31.3% reduction of irrigation water than that of W2). Thus, our studies suggested that one irrigation event in jointing stage for the S086 variety was essential to meet the win-win goal of high crop yield and water use efficiency with low groundwater consumption.

Abstract While the ambient N 2 reduction to ammonia (NH 3 ) using H 2 O as hydrogen source (2N 2 +6H 2 O=4NH 3 +3O 2 ) is known as a promising alternative to the Haber–Bosch process, the high bond energy of N≡N bond leads to the extremely low NH 3 yield. Herein, we report a highly efficient catalytic system for ammonia synthesis using the low‐temperature dielectric barrier discharge plasma to activate inert N 2 molecules into the excited nitrogen species, which can efficiently react with the confined and concentrated H 2 O molecules in porous metal–organic framework (MOF) reactors with V 3+ , Cr 3+ , Mn 3+ , Fe 3+ , Co 2+ , Ni 2+ and Cu 2+ ions. Specially, the Fe‐based catalyst MIL‐100(Fe) causes a superhigh NH 3 yield of 22.4 mmol g −1 h −1 . The investigation of catalytic performance and systematic characterizations of MIL‐100(Fe) during the plasma‐driven catalytic reaction unveils that the in situ generated defective Fe−O clusters are the highly active sites and NH 3 molecules indeed form inside the MIL‐100(Fe) reactor. The theoretical calculation reveals that the porous MOF catalysts have different adsorption capacity for nitrogen species on different catalytic metal sites, where the optimal MIL‐100(Fe) has the lowest energy barrier for the rate‐limiting *NNH formation step, significantly enhancing efficiency of nitrogen fixation.

Abstract The limited design strategy of three‐dimensional covalent organic frameworks (3D COFs) greatly restricts their structural diversification and potential applications. Herein, we propose an inwardly directed linker propagation strategy for the targeted assembly of 3D COFs (COF‐IN‐1 and COF‐IN‐2) and compare them with outwardly directed expanded COFs (COF‐OUT‐1 and COF‐OUT‐2). COF‐OUTs exhibit planar heteroporous 2D frameworks with cpt topology, while COF‐INs engineer controlled triple entanglements into networks, forming 3D frameworks with acs topology. Moreover, the COFs assembled via inwardly directed linker propagation effectively enhanced the production of H 2 O 2 photosynthesis. To demonstrate the application potential, a biphasic fluid system was constructed for continuous H 2 O 2 photosynthesis and extraction. This work not only expands the design strategy for achieving 3D COFs but also demonstrates that the dimensional regulation of frameworks and tuning of applications can arise from different expanding directions of the linkers.

Abstract The design of three‐dimensional covalent organic frameworks (3D COFs) using linear and trigonal linkers remains challenging due to the difficulty in achieving a specific non‐planar spatial arrangement with low‐connectivity building units. Here, we report the novel 3D COFs with linear and trigonal linkers, termed TMB‐COFs, exhibiting srs topology. The steric hindrance provides an additional force to alter the torsion angles of peripheral triangular units, guiding the linear unit to connect with the trigonal unit into 3D srs frameworks, rather than the more commonly observed two‐dimensional (2D) hcb structures. Furthermore, we comprehensively examined the hydrogen peroxide photocatalytic production capacity of the TMB‐COFs in comparison with analogous 2D COFs. The experimental results and DFT calculations demonstrate a significant enhancement in photocatalytic hydrogen peroxide production efficacy through framework regulation. This work emphasizes the steric configuration using low connectivity building units, offering a fresh perspective on the design and application of 3D COFs.

Abstract The development of low‐cost, high‐efficiency, and stable electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is a key challenge in water electrolysis. Here, an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo 2 N quantum dots decorated on conductive N‐doped graphene via codoping single‐atom Al and O (denoted as AlO@Mo 2 N‐NrGO) is reported. The conversion of Anderson polyoxometalates anion cluster ([AlMo 6 O 24 H 6 ] 3− , denoted as AlMo6) to Mo 2 N quantum dots not only result in the generation of more exposed active sites but also in situ codoping atomically dispersed Al and O, that can fine‐tune the electronic structure of Mo 2 N. It is also identified that the surface reconstruction of AlOH hydrates in AlO@Mo 2 N quantum dots plays an essential role in enhancing hydrophilicity and lowering the energy barriers for water dissociation and hydrogen desorption, resulting in a remarkable alkaline HER performance, even better than the commercial 20% Pt/C. Moreover, the strong interfacial interaction (MoN bonds) between AlO@Mo 2 N and N‐doped graphene can significantly improve electron transfer efficiency and interfacial stability. As a result, outstanding stability over 300 h at a current density higher than 100 mA cm −2 is achieved, demonstrating great potential for the practical application of this catalyst.

Abstract The targeted construction of efficient CO 2 capture platforms for photocatalysis remains a significant challenge. Herein, we precisely engineered a proton clamp within a series of covalent organic frameworks (COFs) to function as CO 2 traps, thereby significantly enhancing the photocatalytic reduction of CO 2 to CO. The proton clamp was rationally designed by using an S‐shaped molecular motif featuring appropriate interatomic distances and strategically positioned protonation sites. Remarkably, the protonated COFs exhibited a superior CO production rate of 109 µmol g −1 h −1 in a gas‐solid reaction condition. The experimental and theoretical investigations confirmed that the proton clamp not only facilitated efficient CO 2 trapping but also rapidly delivered protons to the active sites, accelerating the reaction kinetics. This work provides molecular‐level insights into protonation strategies for optimizing photocatalytic CO 2 reduction, offering a new design principle for advanced COF‐based photocatalysts.