A series of stable heterometallic Fe2M cluster‐based MOFs (NNU‐31‐M, M=Co, Ni, Zn) photocatalysts are presented. They can achieve the overall conversion of CO2 and H2O into HCOOH and O2 without the ...assistance of additional sacrificial agent and photosensitizer. The heterometallic cluster units and photosensitive ligands excited by visible light generate separated electrons and holes. Then, low‐valent metal M accepts electrons to reduce CO2, and high‐valent Fe uses holes to oxidize H2O. This is the first MOF photocatalyst system to finish artificial photosynthetic full reaction. It is noted that NNU‐31‐Zn exhibits the highest HCOOH yield of 26.3 μmol g−1 h−1 (selectivity of ca. 100 %). Furthermore, the DFT calculations based on crystal structures demonstrate the photocatalytic reaction mechanism. This work proposes a new strategy for how to design crystalline photocatalyst to realize artificial photosynthetic overall reaction.
A series of stable heterometallic Fe2M cluster‐based MOFs achieve the overall conversion of CO2 and H2O into HCOOH and O2 without the assistance of additional sacrificial agent and photosensitizer. A strategy is proposed to design crystalline photocatalysts to realize the overall artificial photosynthetic reaction.
Abstract
The electrochemical CO
2
reduction to high-value-added chemicals is one of the most promising and challenging research in the energy conversion field. An efficient ECR catalyst based on a ...Cu-based conductive metal-organic framework (Cu-DBC) is dedicated to producing CH
4
with superior activity and selectivity, showing a Faradaic efficiency of CH
4
as high as ~80% and a large current density of −203 mA cm
−2
at −0.9 V vs. RHE. The further investigation based on theoretical calculations and experimental results indicates the Cu-DBC with oxygen-coordinated Cu sites exhibits higher selectivity and activity over the other two crystalline ECR catalysts with nitrogen-coordinated Cu sites due to the lower energy barriers of Cu-O
4
sites during ECR process. This work unravels the strong dependence of ECR selectivity on the Cu site coordination environment in crystalline porous catalysts, and provides a platform for constructing highly selective ECR catalysts.
•Lanthanide molecular probes are promising candidates for NIR bioimaging and biosensing.•We summarized the design, synthesis and applications of lanthanide complexes for bioimaging.•Lanthanide ...complexes will be the next generation biomedical theranostic agents.
Recent advances in NIR detector bloom the design of NIR fluorophores for bioimaging guided diagnosis and therapeutics, with reduced light-tissue interaction, enhanced signal-to-noise ratio and increased penetration depth. NIR lanthanide molecular probes represent an important and emerging group of NIR imaging and sensing materials with attractive structural and photophysical characteristics including small sizes, metal-centered emission, long decay lifetime, large Stokes shift and high resistance to photobleaching. In this review, the sensitization of lanthanides and design principle of lanthanide molecular probes were described. We summarized the recent progresses in last decade on NIR luminescent lanthanide molecular probes by precisely tuning the antenna ligands. The development tendency of applying lanthanide molecular probes for in vivo bioimaging and biosensing would also be discussed, showing the unique and attractive properties of lanthanide coordination compounds compared to organic molecules and inorganic quantum nanoparticles.
Artificial photosynthetic diluted CO2 reduction directly driven by natural sunlight is a challenging, but promising way to realize carbon‐resources recycling utilization. Herein, a three‐in‐one ...photocatalytic system of CO2 enrichment, CO2 reduction and H2O oxidation sites is designed for diluted CO2 reduction. A Zn‐Salen‐based covalent organic framework (Zn‐S‐COF) with oxidation and reductive sites is synthesized; then, ionic liquids (ILs) are loaded into the pores. As a result, EmimBF4@Zn‐S‐COF shows a visible‐light‐driven CO2‐to‐CO conversion rate of 105.88 µmol g−1 h−1 under diluted CO2 (15%) atmosphere, even superior than most photocatalysts in high concentrations CO2. Moreover, natural sunlight driven diluted CO2 reduction rate also reaches 126.51 µmol g−1 in 5 h. Further experiments and theoretical calculations reveal that the triazine ring in the Zn‐S‐COF promotes the activity of H2O oxidation and CO2 reduction sites, and the loaded ILs provide an enriched CO2 atmosphere, realizing the efficient photocatalytic activity in diluted CO2 reduction.
This article presents an obstacle-avoidance method for manipulator systems working in a cluttered environment. Based on the concept of the artificial potential field, a velocity potential field ...method is proposed, with the attractive velocity function designed in configuration space and the repulsive velocity function designed in Cartesian space. The attractive and repulsive velocities calculated by the local information together drive the manipulator to reach the target point without colliding with obstacles. To overcome the local minima problem, virtual target points are selected based on the rapidly exploring random trees method, which can consider the global information. The manipulator reaches the virtual target points one by one until the desired target is reached. The proposed method considers both global and local information and can significantly increase the probability of achieving a feasible and continuous trajectory for manipulator systems in cluttered environments. The simulation results verify the effectiveness of the proposed method.
Nucleic acid (NA) computation has been widely developed in the past years to solve kinds of logic and mathematic issues in both information technologies and biomedical analysis. However, the ...difficulty to integrate non‐NA molecules limits its power as a universal platform for molecular computation. Here, we report a versatile prototype of hybridized computation integrated with both nucleic acids and non‐NA molecules. Employing the conformationally controlled ligand converters, we demonstrate that non‐NA molecules, including both small molecules and proteins, can be computed as nucleic acid strands to construct the circuitry with increased complexity and scalability, and can be even programmed to solve arithmetical calculations within the computational nucleic acid system. This study opens a new door for molecular computation in which all‐NA circuits can be expanded with integration of various ligands, and meanwhile, ligands can be precisely programmed by the nuclei acid computation.
With utilization of conformationally controlled ligand converters, different kinds of non‐nucleic acid molecules, including both small molecules and proteins, can be integrated into nucleic acid computation to construct circuitries with increased complexity and scalability and to even perform algorithmic calculations. This hybridized system establishes a universal platform for molecular computation.
Although photocatalytic C−H activation has been realized by using heterogeneous catalysts, most of them require high‐temperature conditions to provide the energy required for C−H bond breakage. The ...catalysts with photothermal conversion properties can catalyze this reaction efficiently at room temperature, but so far, these catalysts have been rarely developed. Here, we construct bifunctional catalysts Rh‐COF‐316 and ‐318 to combine photosensitive covalent organic frameworks (COFs) and transition‐metal catalytic moiety using a post‐synthetic approach. The Rh‐COF enable the heterogeneous C−H activation reaction by photothermal conversion for the first time, and exhibit excellent yields (up to 98 %) and broad scope of substrates in 4+2 annulation at room temperature, while maintaining the high stability and recyclability. Significantly, this work is the highest yield reported so far in porous materials catalyzing C(sp2)−C(sp2) formation at room temperature. The excellent performances can be attributed to the COF‐316, which enhances the photothermal effect (ΔT=50.9 °C), thus accelerating C−H bond activation and the exchange of catalyst with substrates.
In this work, a general post‐synthetic strategy for constructing bifunctional catalysts, Rh‐COF, which connect photosensitive covalent organic frameworks and transition‐metal catalytic groups through covalent bonding, was developed. Fascinatingly, such complexes enable efficient photothermal conversion properties, which can improve the photothermal catalytic performances in C−H activation to obtain excellent yield, substrate suitability and recyclability.
2D nanomaterials with flexibly modifiable surfaces are highly sought after for various applications, especially in room‐temperature chemiresistive gas sensing. Here, we have prepared a series of COF ...2D nanomaterials (porphyrin‐based COF nanosheets (NS)) that enabled highly sensitive and specific‐sensing of NO2 at room temperature. Different from the traditional 2D sensing materials, H2‐TPCOF was designed with a largely reduced interlayer interaction and predesigned porphyrin rings as modifiable sites on its surfaces for post‐metallization. After post‐metallization, the metallized M‐TPCOF (M=Co and Cu) showed remarkably improved sensing performances. Among them, Co‐TPCOF exhibited highly specific sensing toward NO2 with one of the highest sensitivities of all reported 2D materials and COF materials, with an ultra‐low limit‐of‐detection of 6.8 ppb and fast response/recovery. This work might shed light on designing and preparing a new type of surface‐highly‐modifiable 2D material for various chemistry applications.
A series of metalloporphyrin covalent organic framework based nanosheets has been synthesized and successfully applied in specific sensing of NO2 at room temperature.
Despite wide applications of bimetallic electrocatalysis in oxygen evolution reaction (OER) owing to their superior performance, the origin of the improved performance remains elusive. The underlying ...mechanism was explored by designing and synthesizing a series of stable metal–organic frameworks (MOFs: NNU‐21–24) based on trinuclear metal carboxylate clusters and tridentate carboxylate ligands. Among the examined stable MOFs, NNU‐23 exhibits the best OER performance; particularly, compared with monometallic MOFs, all the bimetallic MOFs display improved OER activity. DFT calculations and experimental results demonstrate that introduction of the second metal atom can improve the activity of the original atom. The proposed model of bimetallic electrocatalysts affecting their OER performance can facilitate design of efficient bimetallic catalysts for energy storage and conversion, and investigation of the related catalytic mechanisms.
An iron atom in an Fe3 cluster is replaced by a second metal to form Fe2M clusters, which can serve as nodes to bridge with organic ligands and construct stable bimetallic MOFs. The introduction of the second metal atom can improve the activity of the original atom and thus improve the oxygen evolution reaction performance of electrocatalysts.
Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and ...good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag‐N2C2/CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag‐N2C2 configuration have been identified by aberration‐correction high‐angle‐annular‐dark‐field scanning transmission electron microscopy (AC‐HAADF‐STEM) and extended X‐ray absorption. Experiments and DFT calculations further verify that Ag‐N2C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag‐N2C2/CN catalyst exhibits much better H2 evolution activity than the N‐coordinated Ag single atom in CN (Ag‐N4/CN), and is even superior to the Pt nanoparticle‐loaded CN (PtNP/CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.
A new Ag single atom in carbon nitride (Ag‐N2C2/CN) photocatalyst with Ag‐N2C2 configuration is developed. It affords fast charge transfer, high Ag loading, and good stability. Noteworthily, the Ag‐N2C2/CN exhibits much better hydrogen evolution activity than Ag‐N4/CN, and even superior to the platinum‐loaded CN.
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