Covalent organic frameworks (COFs), as a new emerging class of highly crystalline advanced porous materials with fascinating structural tunability and diversity as well as the desired semiconductor ...properties, have gained significant attention as highly promising and efficient photocatalysts or designer platforms for a variety of photocatalytic applications in recent years; thus a comprehensive review is timely to summarize the advances of this field. In this review, a background and brief timeline concerning the developments and key achievements of COFs are provided. Afterwards, a systematic overview of the potential photocatalytic applications realized to date in the fast growing field of COFs is provided with the aim of presenting a full blueprint of COFs for possible photochemical energy conversion and reactions. Finally, the challenges remaining and personal perspectives on further development of this type of material for photocatalysis are presented.
In this review, a comprehensive summary of the potential photocatalytic applications realized to date in the fast-growing field of COFs is provided with the aim to present a full blueprint of COFs for photochemical energy conversion and reactions.
A benzodifuran-based donor-acceptor covalent organic framework was synthesized and employed for efficient simulated sunlight-driven photocatalytic hydrogen evolution from water, which exhibited a ...superior and steady hydrogen evolution rate of 1390 μmol g
−1
h
−1
and an outstanding apparent quantum yield (AQY) of 7.8% was obtained at 420 nm.
A benzodifuran-functionalized donor-acceptor covalent organic framework was synthesized and employed for efficient sunlight-driven hydrogen evolution from water.
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•This review comprehensively overviews the potential of COFs for photocatalysis and photothermal catalysis.•The synthetic strategies for the COF-based photocatalysts are discussed in ...detail.•The application scope and corresponding reaction mechanism of COF-based photocatalysts is systematically investigated.•Foreseeable challenges and perspectives for the development of COF-based photocatalysts are proposed.
Light-involved catalysis, including photocatalysis and photothermal catalysis, has been considered as one of the most promising alternatives to traditional thermocatalysis for various organic transformation reactions, while the development of highly efficient photocatalysts is the prerequisite and of significant importance in the field of light-mediated catalysis. Covalent organic frameworks (COFs) represent a new class of crystalline molecular solids with periodically ordered skeletons that feature a series of unique properties, such as structural designability and durability, extensive π-electron conjugations, light-harvesting as well as semiconducting characteristics. Benefiting from these outstanding properties, the blooming development of COFs in recent years has brought promising impetus for the realization of visible-light induced organic transformations by photocatalysis or photothermal catalysis. In this review, the up-to-date applications of COFs as versatile platforms for various selective light-initiated organic transformations were comprehensively summarized and discussed. Firstly, the general background and synthetic strategies of COF-based photocatalysts were briefly introduced, followed by the detailed classification and discussion of each type of reactions reported thus far. Finally, the limitations, critical challenges, and future perspectives of COF photocatalysis and photothermal catalysis were provided. It is anticipated that this review can serve as a starting point for the researchers to get in-depth insight into this largely unexplored but promising field and stimulate more intensive research for rational design of more efficient COF-based photocatalysts to achieve more creative visible-light involved photosynthesis.
Covalent organic frameworks (COFs), featuring semiconductor-like behavior, have recently garnered widespread interest for applications in photocatalysis by virtue of their well-defined and tailorable ...porous structures, high surface areas and excellent chemical stability. A facile strategy for designing COFs exerting efficient charge transfer and separation as well as suppressing charge carrier recombination is the precise integration of electron-donating and electron-withdrawing moieties to form long-range ordered donor-acceptor (D-A) type structures. In this work, we rationally designed and synthesized a novel imine-linked COF (
DABT-Py-COF
) by the condensation of a newly designed D-A-D type monomer of 4,4′,4′′,4′′′-(benzo
c
1,2,5thiadiazole-4,7-diylbis(9,9-dimethyl-9,10-dihydroacridine-10,2,7-triyl))tetrabenzaldehyde and 1,3,6,8-tetrakis(4-aminophenyl)pyrene under solvothermal conditions. Remarkably, the obtained
DABT-Py-COF
exhibited outstanding and steady hydrogen production with a maximum hydrogen evolution rate (HER) of 5458 μmol g
−1
h
−1
under visible-light irradiation (AM 1.5). This work has paved the way for the rational design and preparation of more efficient D-A type COFs for photocatalysis.
Derived from a D-A-D motif monomer, a novel COF was designed and synthesized, which exhibited excellent efficiency for hydrogen evolution from water under visible-light irradiation as a photocatalyst.
A fully sp
-carbon conjugated COF (Py-FTP-COF) was designed and synthesized, exhibiting excellent hydrogen evolution rate of 5.22 mmol g
h
. More importantly,
hydrogenation of nitroarenes under ...visible-light irradiation without any additional hydrogen source was successfully accomplished for the first time over COF-based materials.
Multicomponent reactions (MCRs), as a powerful one-pot combinatorial synthesis tool, have been recently applied to the synthesis of covalent organic frameworks (COFs). Compared with the thermally ...driven MCRs, the photocatalytic MCR-based COF synthesis has not yet been investigated. Herein, we first report the construction of COFs by a photocatalytic multicomponent reaction. Upon visible-light irradiation, a series of COFs with excellent crystallinity, stability, and permanent porosity are successfully synthesized via photoredox-catalyzed multicomponent Petasis reaction under ambient conditions. Additionally, the obtained Cy-N 3 -COF exhibits excellent photoactivity and recyclability for the visible-light-driven oxidative hydroxylation of arylboronic acids. The concept of photocatalytic multicomponent polymerization not only enriches the methodology for COF synthesis but also opens a new avenue for the construction of COFs that might not be possible with the existing synthetic methods based on thermally driven MCRs.
Hydrogen peroxide (H
2
O
2
), as an important environmentally friendly oxidant, has been widely used in bleaching, disinfection, wastewater treatment and chemical synthesis, while the artificial ...photosynthesis of H
2
O
2
from H
2
O and O
2
over certain photocatalysts has been considered as a clean and energy-saving approach and has been widely explored in recent years. Covalent organic frameworks (COFs) represent a newly blooming class of crystalline porous materials with periodically ordered structures that possess a set of intriguing features, including diverse structural designability and durability, high porosity and low density, wide light-harvesting ability and semiconducting properties. Benefiting from these particular properties, the blooming developments of COFs in recent years have brought promising impetus for the realization of efficient visible-light driven H
2
O
2
production. Thus, a systematic and comprehensive review is timely to provide constructive guidance for the development and rational design of more efficient COF-based photocatalysts. In this review, the up-to-date application of COF-based photocatalysts for H
2
O
2
photosynthesis was comprehensively summarized and discussed. Firstly, the general background and fundamental principles of COF-based photocatalysts for photocatalytic H
2
O
2
production were briefly introduced, followed by the detailed classification and discussion of the strategies reported thus far for realizing improved photocatalytic performance. In addition, the challenges and prospects of COF-based photocatalysts for visible-light driven H
2
O
2
production were addressed.
This review comprehensively summarized and discussed the up-to-date application of COF-based photocatalysts for efficient H
2
O
2
photosynthesis, aiming to provide constructive guidance for the fast development of this field.
We have successfully developed a novel synthetic route for the synthesis of naphthyridinones. This was achieved through a reaction between formyl-phenylpropiolamides and arylamines, utilizing an ...intramolecular Povarov reaction. Notably, this reaction exhibited remarkable tolerance towards a wide range of substituents, resulting in the formation of diverse products using simple reaction conditions. Additionally, we discovered that the same substrates can undergo intramolecular carbonyl-alkyne metathesis reactions in the absence of anilines. This versatile transformation enabled the synthesis of quinolinones and chromen-2-ones with high yields.
In this study, we aimed to investigate the effect of electro-acupuncture (EA) pretreatment at zusanli (ST36) acupoint on lipopolysaccharide (LPS)-induced endotoxemic rat model and explore the ...underlying molecular mechanisms. Rats were treated with EA at ST36 for 7 days before being subjected to LPS. Two hours post-LPS, samples such as serum, local acupoint tissues, and spleens were collected and processed for investigations including cytokine production, cytosolic calcium (Ca
2+
) concentration, Ca
2+
influx, cannabinoid CB2 receptor (CB2R) expression, and TLR4/NF-κB signaling. Our results showed EA pretreatment significantly attenuated LPS-induced inflammatory cytokine production, such as TNF-α, IL-1β, and IL-6. EA also enhanced CB2R expression, inhibited Ca
2+
influx, and inactivated TLR4/NF-κB signaling, subsequently resulting in a substantial reduction of Ca
2+
concentration. Importantly, CB2R antagonist AM630 effectively abrogated the suppressive effect of EA at ST36 on the endotoxemic rats, suggesting CB2R was involved in the anti-inflammatory effect of EA. EA pretreatment could enhance CB2R expression, inhibit Ca
2+
influx, and inactivate TLR4/NF-κB signaling, which contributes to the alleviation of LPS-induced inflammation in rats.
Background
Early diagnosis of hepatocellular carcinoma (HCC) can significantly improve patient survival. We aimed to develop a blood‐based assay to aid in the diagnosis, detection and prognostic ...evaluation of HCC.
Methods
A three‐phase multicentre study was conducted to screen, optimise and validate HCC‐specific differentially methylated regions (DMRs) using next‐generation sequencing and quantitative methylation‐specific PCR (qMSP).
Results
Genome‐wide methylation profiling was conducted to identify DMRs distinguishing HCC tumours from peritumoural tissues and healthy plasmas. The twenty most effective DMRs were verified and incorporated into a multilocus qMSP assay (HepaAiQ). The HepaAiQ model was trained to separate 293 HCC patients (Barcelona Clinic Liver Cancer (BCLC) stage 0/A, 224) from 266 controls including chronic hepatitis B (CHB) or liver cirrhosis (LC) (CHB/LC, 96), benign hepatic lesions (BHL, 23), and healthy controls (HC, 147). The model achieved an area under the curve (AUC) of 0.944 with a sensitivity of 86.0% in HCC and a specificity of 92.1% in controls. Blind validation of the HepaAiQ model in a cohort of 523 participants resulted in an AUC of 0.940 with a sensitivity of 84.4% in 205 HCC cases (BCLC stage 0/A, 167) and a specificity of 90.3% in 318 controls (CHB/LC, 100; BHL, 102; HC, 116). When evaluated in an independent test set, the HepaAiQ model exhibited a sensitivity of 70.8% in 65 HCC patients at BCLC stage 0/A and a specificity of 89.5% in 124 patients with CHB/LC. Moreover, HepaAiQ model was assessed in paired pre‐ and postoperative plasma samples from 103 HCC patients and correlated with 2‐year patient outcomes. Patients with high postoperative HepaAiQ score showed a higher recurrence risk (Hazard ratio, 3.33, p < .001).
Conclusions
HepaAiQ, a noninvasive qMSP assay, was developed to accurately measure HCC‐specific DMRs and shows great potential for the diagnosis, detection and prognosis of HCC, benefiting at‐risk populations.
The HepaAiQ assay integrates the most effective HCC‐specific methylation biomarkers using multilocus quantitative PCR.
In multicentre studies, the HepaAiQ model accurately distinguishes HCC from other liver diseases, surpassing existing serum tests.
The HepaAiQ excels in early‐stage HCC detection in high‐risk patients and post‐resection assessment, potentially fulfilling clinical needs with high accuracy, accessibility and affordability.
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