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1.
Proc Natl Acad Sci U S A ; 120(13): e2218819120, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36943875

RESUMEN

Certain ciliary transmembrane and membrane-tethered signaling proteins migrate from the ciliary tip to base via retrograde intraflagellar transport (IFT), essential for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. During this process, the BBSome functions as an adaptor between retrograde IFT trains and these signaling protein cargoes. The Arf-like 13 (ARL13) small GTPase resembles ARL6/BBS3 in facilitating these signaling cargoes to couple with the BBSome at the ciliary tip prior to loading onto retrograde IFT trains for transporting towards the ciliary base, while the molecular basis for how this intricate coupling event happens remains elusive. Here, we report that Chlamydomonas ARL13 only in a GTP-bound form (ARL13GTP) anchors to the membrane for diffusing into cilia. Upon entering cilia, ARL13 undergoes GTPase cycle for shuttling between the ciliary membrane (ARL13GTP) and matrix (ARL13GDP). To achieve this goal, the ciliary membrane-anchored BBS3GTP binds the ciliary matrix-residing ARL13GDP to activate the latter as an ARL13 guanine nucleotide exchange factor. At the ciliary tip, ARL13GTP recruits the ciliary matrix-residing and post-remodeled BBSome as an ARL13 effector to anchor to the ciliary membrane. This makes the BBSome spatiotemporally become available for the ciliary membrane-tethered phospholipase D (PLD) to couple with. Afterward, ARL13GTP hydrolyzes GTP for releasing the PLD-laden BBSome to load onto retrograde IFT trains. According to this model, hedgehog signaling defects associated with ARL13b and BBS3 mutations in humans could be satisfactorily explained, providing us a mechanistic understanding behind BBSome-cargo coupling required for proper ciliary signaling.


Asunto(s)
Síndrome de Bardet-Biedl , Cilios , Humanos , Cilios/metabolismo , Transporte de Proteínas/genética , Síndrome de Bardet-Biedl/genética , Proteínas Hedgehog/metabolismo , Proteínas de la Membrana/metabolismo , Guanosina Trifosfato/metabolismo , Flagelos/metabolismo
2.
Mol Psychiatry ; 29(5): 1417-1426, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38278992

RESUMEN

Human genetic studies indicate that suicidal ideation and behavior are both heritable. Most studies have examined associations between aberrant gene expression and suicide behavior, but behavior risk is linked to the severity of suicidal ideation. Through a gene network approach, this study investigates how gene co-expression patterns are associated with suicidal ideation and severity using RNA-seq data in peripheral blood from 46 live participants with elevated suicidal ideation and 46 with no ideation. Associations with the presence of suicidal ideation were found within 18 co-expressed modules (p < 0.05), as well as in 3 co-expressed modules associated with suicidal ideation severity (p < 0.05, not explained by severity of depression). Suicidal ideation presence and severity-related gene modules with enrichment of genes involved in defense against microbial infection, inflammation, and adaptive immune response were identified and investigated using RNA-seq data from postmortem brain that revealed gene expression differences with moderate effect sizes in suicide decedents vs. non-suicides in white matter, but not gray matter. Findings support a role of brain and peripheral blood inflammation in suicide risk, showing that suicidal ideation presence and severity are associated with an inflammatory signature detectable in blood and brain, indicating a biological continuity between ideation and suicidal behavior that may underlie a common heritability.


Asunto(s)
Encéfalo , Ideación Suicida , Suicidio , Transcriptoma , Humanos , Femenino , Masculino , Transcriptoma/genética , Suicidio/psicología , Adulto , Encéfalo/metabolismo , Persona de Mediana Edad , Redes Reguladoras de Genes/genética , Depresión/genética , Depresión/sangre , Inflamación/genética , Inflamación/sangre
3.
J Transl Med ; 22(1): 161, 2024 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365674

RESUMEN

BACKGROUND: The autophagy adapter SQSTM1/p62 is crucial for maintaining homeostasis in various organs and cells due to its protein-protein interaction domains and involvement in diverse physiological and pathological processes. Vascular endothelium cells play a unique role in vascular biology and contribute to vascular health. METHODS: Using the Cre-loxP system, we generated mice with endothelium cell-specific knockout of p62 mediated by Tek (Tek receptor tyrosine kinase)-cre to investigate the essential role of p62 in the endothelium. In vitro, we employed protein mass spectrometry and IPA to identify differentially expressed proteins upon knockdown of p62. Immunoprecipitation assays were conducted to demonstrate the interaction between p62 and FN1 or LAMC2 in human umbilical vein endothelium cells (HUVECs). Additionally, we identified the degradation pathway of FN1 and LAMC2 using the autophagy inhibitor 3-methyladenine (3-MA) or proteasome inhibitor MG132. Finally, the results of immunoprecipitation demonstrated that the interaction between p62 and LAMC2 was abolished in the PB1 truncation group of p62, while the interaction between p62 and FN1 was abolished in the UBA truncation group of p62. RESULTS: Our findings revealed that p62 Endo mice exhibited heart, lung, and kidney fibrosis compared to littermate controls, accompanied by severe cardiac dysfunction. Immunoprecipitation assays provided evidence of p62 acting as an autophagy adapter in the autophagy-lysosome pathway for FN1 and LAMC2 degradation respectively through PB1 and UBA domain with these proteins rather than proteasome system. CONCLUSIONS: Our study demonstrates that defects in p62 within endothelium cells induce multi-organ fibrosis and cardiac dysfunction in mice. Our findings indicate that FN1 and LAMC2, as markers of (EndoMT), have detrimental effects on HUVECs and elucidate the autophagy-lysosome degradation mechanism of FN1 and LAMC2.


Asunto(s)
Cardiopatías , Proteína Sequestosoma-1 , Animales , Humanos , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Autofagia , Endotelio/metabolismo , Cardiopatías/genética , Cardiopatías/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Complejo de la Endopetidasa Proteasomal/farmacología , Proteína Sequestosoma-1/genética , Proteína Sequestosoma-1/metabolismo , Fibrosis/genética , Fibrosis/metabolismo
4.
Respir Res ; 25(1): 267, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38970088

RESUMEN

BACKGROUND: Lung cancer is the second most common cancer with the highest mortality in the world. Calumenin as a molecular chaperone that not only binds various proteins within the endoplasmic reticulum but also plays crucial roles in diverse processes associated with tumor development. However, the regulatory mechanism of calumenin in lung adenocarcinoma remains elusive. Here, we studied the impact of calumenin on lung adenocarcinoma and explored possible mechanisms. METHODS: 5-ethynyl-2'-deoxyuridine assay, colony formation, transwell and wound healing assays were performed to explore the effects of calumenin on the proliferation and migration of lung adenocarcinoma cells. To gain insights into the underlying mechanisms through which calumenin knockdown inhibits the migration and proliferation of lung adenocarcinoma, we performed Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Gene Set Enrichment Analysis and Ingenuity Pathway Analysis based on transcriptomics by comparing calumenin knockdown with normal A549 cells. RESULTS: The mRNA and protein levels of calumenin in lung adenocarcinoma are highly expressed and they are related to an unfavorable prognosis in this disease. Calumenin enhances the proliferation and migration of A549 and H1299 cells. Gene Set Enrichment Analysis revealed that knockdown of calumenin in A549 cells significantly inhibited MYC and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog signaling pathways while activating interferon signals, inflammatory signals, and p53 pathways. Ingenuity pathway analysis provided additional insights, indicating that the interferon and inflammatory pathways were prominently activated upon calumenin knockdown in A549 cells. CONCLUSIONS: The anti-cancer mechanism of calumenin knockdown might be related to the inhibition of MYC and KRAS signals but the activation of interferon signals, inflammatory signals and p53 pathways.


Asunto(s)
Adenocarcinoma del Pulmón , Movimiento Celular , Proliferación Celular , Neoplasias Pulmonares , Invasividad Neoplásica , Humanos , Proliferación Celular/fisiología , Movimiento Celular/fisiología , Adenocarcinoma del Pulmón/patología , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/genética , Progresión de la Enfermedad , Células A549 , Proteínas de Unión al Calcio/metabolismo , Proteínas de Unión al Calcio/genética , Regulación Neoplásica de la Expresión Génica
5.
Chem Rev ; 122(6): 5411-5475, 2022 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-35014799

RESUMEN

In recent years, the continuous development of magnetic nanostructures (MNSs) has tremendously promoted both fundamental scientific research and technological applications. Different from the bulk magnet, the systematic engineering on MNSs has brought a great breakthrough in some emerging fields such as the construction of MNSs, the magnetism exploration of multidimensional MNSs, and their potential translational applications. In this review, we give a detailed description of the synthetic strategies of MNSs based on the fundamental features and application potential of MNSs and discuss the recent progress of MNSs in the fields of nanomedicines, advanced nanobiotechnology, catalysis, and electromagnetic wave adsorption (EMWA), aiming to provide guidance for fabrication strategies of MNSs toward diverse applications.


Asunto(s)
Nanoestructuras , Adsorción , Catálisis , Fenómenos Magnéticos , Nanomedicina , Nanoestructuras/química
6.
Int J Mol Sci ; 25(6)2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38542520

RESUMEN

Injuries and subclinical effects from exposure to blasts are of significant concern in military operational settings, including tactical training, and are associated with self-reported concussion-like symptomology and physiological changes such as increased intestinal permeability (IP), which was investigated in this study. Time-series gene expression and IP biomarker data were generated from "breachers" exposed to controlled, low-level explosive blast during training. Samples from 30 male participants at pre-, post-, and follow-up blast exposure the next day were assayed via RNA-seq and ELISA. A battery of symptom data was also collected at each of these time points that acutely showed elevated symptom reporting related to headache, concentration, dizziness, and taking longer to think, dissipating ~16 h following blast exposure. Evidence for bacterial translocation into circulation following blast exposure was detected by significant stepwise increase in microbial diversity (measured via alpha-diversity p = 0.049). Alterations in levels of IP protein biomarkers (i.e., Zonulin, LBP, Claudin-3, I-FABP) assessed in a subset of these participants (n = 23) further evidenced blast exposure associates with IP. The observed symptom profile was consistent with mild traumatic brain injury and was further associated with changes in bacterial translocation and intestinal permeability, suggesting that IP may be linked to a decrease in cognitive functioning. These preliminary findings show for the first time within real-world military operational settings that exposures to blast can contribute to IP.


Asunto(s)
Traumatismos por Explosión , Conmoción Encefálica , Personal Militar , Humanos , Masculino , Personal Militar/psicología , Funcion de la Barrera Intestinal , Traumatismos por Explosión/complicaciones , Conmoción Encefálica/complicaciones , Biomarcadores
7.
Molecules ; 29(13)2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38999150

RESUMEN

Functionalized imidazo[1,2-α]pyridines are important scaffolds in pharmaceuticals. Herein, we present an efficient 3-sulfonylmethylation protocol for imidazo[1,2-α]pyridines by sodium sulfinates in DMA and H2O (2:1) via an FeCl3-catalyzed three-component coupling reaction. Various sulfonylmethyl imidazo[1,2-α]pyridines were thus afforded in high yields with excellent functional group tolerance. A plausible oxidation-addition mechanism was proposed.

8.
J Am Chem Soc ; 145(11): 6112-6122, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36883963

RESUMEN

Rational design of crystalline catalysts with superior light absorption and charge transfer for efficient photoelectrocatalytic (PEC) reaction coupled with energy recovery remains a great challenge. In this work, we elaborately construct three stable titanium-oxo clusters (TOCs, Ti10Ac6, Ti10Fc8, and Ti12Fc2Ac4) modified with a monofunctionalized ligand (9-anthracenecarboxylic acid (Ac) or ferrocenecarboxylic acid (Fc)) and bifunctionalized ligands (Ac and Fc). They have tunable light-harvesting and charge transfer capacities and thus can serve as outstanding crystalline catalysts to achieve efficient PEC overall reaction, that is, the integration of anodic organic pollutant 4-chlorophenol (4-CP) degradation and cathodic wastewater-to-H2 conversion. These TOCs can all exhibit very high PEC activity and degradation efficiency of 4-CP. Especially, Ti12Fc2Ac4 decorated with bifunctionalized ligands exhibits better PEC degradation efficiency (over 99%) and H2 generation than Ti10Ac6 and Ti10Fc8 modified with a monofunctionalized ligand. The study of the 4-CP degradation pathway and mechanism revealed that such better PEC performance of Ti12Fc2Ac4 is probably due to its stronger interactions with the 4-CP molecule and better •OH radical production. This work not only presents the effective combination of organic pollutant degradation and simultaneously H2 evolution reaction using crystalline coordination clusters as both anodic and cathodic catalyst but also develops a new PEC application for crystalline coordination compounds.

9.
Cancer Immunol Immunother ; 72(6): 1479-1492, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36472587

RESUMEN

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis and limited effective treatment options. Notably, immunotherapy is a potential therapeutic approach for TNBC. This study performed single-cell RNA sequencing on TNBC and found highly expressed CXCL9 in M1 macrophages. An intercellular communication network was found between M1 macrophages and M2 macrophages, and M1 macrophages could differentiate into M2 macrophages over time. Meanwhile, CXCL9 expression started to decrease in association with cell differentiation from M1 macrophages to M2 macrophages. Additionally, the M1 macrophage had strong connections to the M2 macrophage in the MHC-II signaling network. Through GSVA analysis, the MHC-II pathway activity of the M1 macrophages was significantly stronger than that of the M2 macrophages. Furthermore, CXCL9 was enriched in the MHC-II signaling pathway. CXCL9 was significantly enriched in the JAK/STAT signaling pathway. Western blot revealed that CXCL9 overexpression promotes JAK1/STAT2 expression in MDA-MB-231 cells. These findings indicate that CXCL9 is a potential clinical biomarker of prognosis and immunotherapy efficacy for TNBC patients. Also, it stimulates JAK/STAT activity, which in turn modifies the tumor microenvironment.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/patología , Transducción de Señal/genética , Quinasas Janus/metabolismo , Microambiente Tumoral , Factores de Transcripción STAT/metabolismo , Línea Celular Tumoral , Quimiocina CXCL9/metabolismo
10.
J Org Chem ; 88(13): 8454-8464, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37364091

RESUMEN

Herein, we report a mild, one-pot method for silver-catalyzed tandem cycloisomerization/[5 + 2] cycloaddition reactions between readily accessible cyclopropyl-tethered allenyl ketones and benzopyranone-derived oxidopyrylium ylides. The reactions proceed via a cyclobutene-fused furan intermediate generated in situ by a cycloisomerization/1,2-carbene transfer/ring-expansion cascade. This method, which features an unprecedented formal [5 + 2] cycloaddition, delivers good to excellent yields of structurally complex bibridged benzocycloheptanones bearing a strained cyclobutane ring and an O-bridged ring.

11.
J Org Chem ; 88(7): 4092-4100, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-36972580

RESUMEN

A novel hydroiodic acid-promoted metal-free C(sp2)-H sulfenylation of electron-rich arenes was developed using stable and easy-to-handle sodium sulfinates as sulfur sources. Diverse kinds of asymmetric aryl sulfides were afforded in good yields from various commercially available aromatic substrates under mild conditions. Comprehensive mechanistic experiments demonstrate that RSO2SR and RSSR are the key intermediates responsible for the redox process.

12.
Nano Lett ; 22(16): 6808-6815, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35947428

RESUMEN

Metallic magnesium is a promising high-capacity anode material for energy storage technologies beyond lithium-ion batteries. However, most reported Mg metal anodes are only cyclable under shallow cycling (≤1 mAh cm-2) and thus poor Mg utilization (<3%) conditions, significantly compromising their energy-dense characteristic. Herein, composite Mg metal anodes with high capacity utilization of 75% are achieved by coating magnesiophilic gold nanoparticles on copper foils for the first time. Benefiting from homogeneous ionic flux and uniform deposition morphology, the Mg-plated Au-Cu electrode exhibits high average Coulombic efficiency of 99.16% over 170 h cycling at 75% Mg utilization. Moreover, the full cell based on Mg-plated Au-Cu anode and Mo6S8 cathode achieves superior capacity retention of 80% after 300 cycles at a low negative/positive ratio of 1.33. This work provides a simple yet effective general strategy to enhance Mg utilization and reversibility, which can be extended to other metal anodes as well.

13.
Nano Lett ; 22(21): 8679-8687, 2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-36315106

RESUMEN

Two-dimensional MXenes produce competitive performances when incorporated into lithium-sulfur batteries (LSBs), solving key problems such as the poor electronic conductivity of sulfur and dissolution of its polysulfide intermediates. However, MXene nanosheets are known to easily aggregate and restack during electrode fabrication, filtration, or water removal, limiting their practical applicability. Furthermore, in complex electrocatalytic reactions like the multistep sulfur reduction process in LSBs, MXene alone is insufficient to ensure an optimal reaction pathway. In this work, we demonstrate for the first time a loose templating of sulfur spheres using Ti3C2Tx MXene nanosheets decorated with polymorphic CoSe2 nanoparticles. This work shows that the templating of sulfur spheres using nanoparticle-decorated MXene nanosheets can prevent nanosheet aggregation and exert a strong electrocatalytic effect, thereby enabling improved reaction kinetics and battery performance. The S@MXene-CoSe2 cathode demonstrated a long cycle life of 1000 cycles and a low capacity decay rate of 0.06% per cycle in LSBs.

14.
J Transl Med ; 20(1): 571, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36474281

RESUMEN

BACKGROUND: Mitochondrial dysfunction is an important pathogenic event in acute kidney injury (AKI). GCN5L1 is a specific acetyltransferase in mitochondria, which regulates glucose and fatty acid metabolism. However, the role of GCN5L1 in mitochondrial dysfunction and the pathogenesis of ischemic AKI are not fully understood. METHODS: The protein level of GCN5L1 was detected by western blot assay. Acetylated proteomics was used to explore the level of acetylated TFAM. Duolink proximity ligation assay and co-immunoprecipitation were used to detect the interaction of TFAM and translocase of outer membrane 70 (TOM70). mtDNA copy number, the expression of mitochondrial electron transport chain complexes, the number and morphology of mitochondria were measured. The renal injury of AKI mice was reflected by the levels of creatinine and urea nitrogen and the pathological changes of renal tissue. RESULTS: We showed that GCN5L1 was highly expressed in vivo and in vitro and renal tubules specific knockdown of GCN5L1 could effectively attenuate AKI-induced mitochondrial impairment. Besides, acetylated proteomics revealed that acetylated TFAM was significantly upregulated in AKI mice kidney, which reminded us that TFAM might be an acetylating substrate of GCN5L1. Mechanistically, we evidenced that GCN5L1 could acetylate TFAM at its K76 site and subsequently inhibited its binding to TOM70, thereby reducing TFAM import into mitochondria and mitochondrial biogenesis. Clinically, GCN5L1 and acetylated TFAM were positively correlated with disease severity (all p < 0.05). CONCLUSIONS: In sum, these data demonstrated an unrecognized regulating mechanism of GCN5L1 on TFAM acetylation and its intracellular trafficking, and a potential intervening target for AKI associated mitochondrial disorders as well.


Asunto(s)
Lesión Renal Aguda , Biogénesis de Organelos , Ratones , Animales , Proteínas de Unión al ADN , Proteínas del Grupo de Alta Movilidad/genética
15.
Inorg Chem ; 61(29): 11182-11188, 2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35798569

RESUMEN

The high theoretical capacity of vanadium oxides makes them promising cathode candidates for the rechargeable lithium-ion batteries (LIBs). Nevertheless, the relatively poor electrical conductivity and capacity retention hinder the practical application and have to be overcome urgently for the increasing demand for storage technologies. Herein, a new BRG system composed of bimetallic oxide/rhodamine B (RB)/reduced graphene oxide (RGO) was prepared through the facile self-sacrificing template of the precursor polyoxometalate (POM) composites POMs/RB/RGO (PRG). RB not only acts as a cationic mediator to facilitate the loading of POMs on graphene for conversion to oxides but also promotes the formation of uniform nanorods on the RGO. The prepared composite FeV3O8-RB/RGO-1 as the cathode exhibits superior cycling stability (specific capacity of 225 mA h g-1 at 100 mA g-1) and elastic rate capabilities for LIBs. What is more, the new PRG precursor provides versatile possibilities for the design of oxide composites from the self-sacrificing template of POMs-based composites with abundant architectural designs and compositions for the energy storage system.

16.
Org Biomol Chem ; 20(45): 8885-8892, 2022 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-36317597

RESUMEN

A controllable and rapid synthesis of disulfides and thiosulfonates from sodium sulfinates mediated by hydroiodic acid is presented for the first time. In these reactions, ethanol and H2O are employed as solvents to generate different products, thiosulfonates can be further transformed to corresponding disulfides in an ethanol reaction system. Moreover, these simple methods are environmentally benign and can be performed under mild conditions with a short reaction time, showing good functional group tolerance.


Asunto(s)
Disulfuros , Sodio , Solventes , Etanol
17.
Molecules ; 27(5)2022 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-35268808

RESUMEN

In recent years, transmission Raman spectroscopy (TRS) has emerged as a potent new tool for rapid, nondestructive quantitation in pharmaceutical manufacturing. In order to expand the applicability of TRS and enhance its use in product quality monitoring during drug production, we aimed, in the present study, to apply partial least-squares (PLS) approaches to build a model consisting of 150 handmade tablets and covering 15 levels through the use of a multifactor orthogonal design of experiment (DOE), which was used to predict concentrations of validation tablets made by hand. The difference between results according to HPLC and TRS were negligible. The model was used to predict the active pharmaceutical ingredient (API) content in four random commercial paracetamol tablets, and corrected with the spectra of the commercial tablets to obtain four corresponding models. The results show that the content relative error in the model's predictions after correction with commercially available tablets was significantly lower than that before correction. The corrected model was used to make predictions for 20 tablets from the brand Panadol. Compared with the HPLC results, the prediction relative error was basically less than 4.00%, and the relative standard deviation (RSD) of the content was 0.86%.


Asunto(s)
Acetaminofén , Espectrometría Raman , Calibración , Cromatografía Líquida de Alta Presión , Análisis de los Mínimos Cuadrados , Espectrometría Raman/métodos , Comprimidos/química
18.
Angew Chem Int Ed Engl ; 61(34): e202207282, 2022 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-35748491

RESUMEN

Hybrid CO2 electroreduction (HCER) is recognized as an important strategy to improve the total value of redox products and energy conversion efficiency. In this work, a coordination catalyst model system (Ni8 -TET with active oxidation sites, Ni-TPP with active reduction sites and PCN-601 with redox-active sites) for HCER was established for the first time. Especially, PCN-601 can complete both anodic methanol oxidation and cathodic CO2 reduction with FEHCOOH and FECO over 90 %. The performance can be further improved with light irradiation (FE nearly 100 %). DFT calculations reveal that the transfer of electrons from NiII 8 clusters to metalloporphyrins under electric fields results in the raised oxidizability of Ni8 clusters and the raised reducibility of metalloporphyrin, which then improves the electrocatalytic performance. This work serves as a well-defined model system and puts forward a new design idea for establishing efficient catalysts for hybrid CO2 electroreduction.

19.
Angew Chem Int Ed Engl ; 61(50): e202212162, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36229417

RESUMEN

Strategy that can design powerful photothermal-catalysts to achieve photothermal-effect assisted coupling-catalysis is much desired for the improvement of energy conversion efficiency and redox product value in CO2 electroreduction system. Herein, a kind of bifunctional viologen-containing covalent organic framework (Ni-2CBpy2+ -COF) has been prepared and successfully applied in photothermal-assisted co-electrolysis of CO2 and methanol. Specifically, the FECO (cathode) and FEHCOOH (anode) for Ni-2CBpy2+ -COF can reach up to ≈100 % at 1.9 V with ≈31.5 % saved overall electricity-consumption when the anodic oxygen evolution reaction (OER) is replaced by methanol oxidation. The superior performance could be attributed to the cyclic diquats in Ni-2CBpy2+ -COF that enhance the photothermal effect (ΔT=49.1 °C) to accelerate faster charge transfer between catalyst and immediate species as well as higher selectivity towards desired products as revealed by DFT calculations and characterizations.

20.
Angew Chem Int Ed Engl ; 60(26): 14536-14544, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-33834580

RESUMEN

Spinel zinc cobalt oxide (ZnCo2 O4 ) is not considered as a superior catalyst for the electrochemical oxygen evolution reaction (OER), which is the bottleneck reaction in water-electrolysis. Herein, taking advantage of density functional theory (DFT) calculations, we find that the existence of low-spin (LS) state cobalt cations hinders the OER activity of spinel zinc cobalt oxide, as the t2g 6 eg 0 configuration gives rise to purely localized electronic structure and exhibits poor binding affinity to the key reaction intermediate. Increasing the spin state of cobalt cations in spinel ZnCo2 O4 is found to propagate a spin channel to promote spin-selected charge transport during OER and generate better active sites for intermediates adsorption. The experiments find increasing the calcination temperature a facile approach to engineer high-spin (HS) state cobalt cations in ZnCo2 O4 , while not working for Co3 O4 . The activity of the best spin-state-engineered ZnCo2 O4 outperforms other typical Co-based oxides.

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