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1.
J Environ Manage ; 355: 120449, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38432012

RESUMO

N-acyl homoserine lactones (AHLs) function as signaling molecules influencing microbial community dynamics. This study investigates the impact of exogenously applied AHLs on methane production during waste-activated sludge (WAS) anaerobic digestion (AD). Nine AHL types, ranging from 10-4 to 10 µg/g VSS, were applied, comparing microbial community composition under optimal AHL concentrations. Firmicutes, Bacteroidetes, Chloroflexi, and Proteobacteria were identified in anaerobic digesters with C4-HSL, C6-HSL, and C8-HSL. Compared to the control, Halobacterota increased by 19.25%, 20.87%, and 9.33% with C7-HSL, C10-HSL, and C12-HSL. Exogenous C7-HSL enhanced the relative abundance of Methanosarcina, Romboutsia, Sedimentibacter, Proteiniclasticum, Christensenellaceae_R-7_group. C10-HSL increased Methanosarcina abundance. C4-HSL, C6-HSL, C8-HSL, C10-HSL, and C12-HSL showed potential to increase unclassified_Firmicutes. Functional Annotation of Prokaryotic Taxa (FAPROTAX) predicted AHLs' impact on related functional genes, providing insights into their role in AD methanogenesis regulation. This study aimed to enhance the understanding of the influence of different types of exogenous AHLs on AD and provide technical support for regulating the methanogenesis efficiency of AD by exogenous AHLs.


Assuntos
4-Butirolactona , 4-Butirolactona/análogos & derivados , Acil-Butirolactonas , Acil-Butirolactonas/farmacologia , Anaerobiose , 4-Butirolactona/farmacologia , Esgotos , Lactonas
2.
Angew Chem Int Ed Engl ; : e202407468, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847274

RESUMO

The creation of frustrated Lewis pairs on catalyst surface is an effective strategy for tuning CO2 activation. The critical step in the formation of frustrated Lewis pairs is the spatial effect of proximal Lewis acid-Lewis base pairs. Here, we demonstrate a facile surface functionalization methodology that enables hydrogen bonding between N and H atoms to mediate the construction of frustrated Lewis pairs in poly(heptazine imide), thereby increasing the propensity to activate CO2 molecules. Experimental and theoretical results show that the construction of active hydrogen bonding regions can facilitate the bending of CO2 molecules. Furthermore, the delocalization of electron clouds induced by the hydrogen bonding-mediated frustrated Lewis pairs can promote the heterolytic cleavage and photocatalytic conversion of CO2. This work highlights the potential of utilizing hydrogen bonding-mediated strategy in heterogeneously photocatalytic activation of CO2 over polymer materials.

3.
Angew Chem Int Ed Engl ; 63(14): e202318236, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38323753

RESUMO

The controllable photocatalytic C-C coupling of methanol to produce ethylene glycol (EG) is a highly desirable but challenging objective for replacing the current energy-intensive thermocatalytic process. Here, we develop a metal-free porous boron nitride catalyst that demonstrates exceptional selectivity in the photocatalytic production of EG from methanol under mild conditions. Comprehensive experiments and calculations are conducted to thoroughly investigate the reaction mechanism, revealing that the OB3 unit in the porous BN plays a critical role in the preferential activation of C-H bond in methanol to form ⋅CH2OH via a concerted proton-electron transfer mechanism. More prominent energy barriers are observed for the further dehydrogenation of the ⋅CH2OH intermediate on the OB3 unit, inhibiting the formation of some other by-products during the catalytic process. Additionally, a small downhill energy barrier for the coupling of ⋅CH2OH in the OB3 unit promotes the selective generation of EG. This study provides valuable insights into the underlying mechanisms and can serve as a guide for the design and optimization of photocatalysts for efficient and selective EG production under mild conditions.

4.
J Cell Mol Med ; 26(10): 2831-2840, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35355403

RESUMO

Phosgene gas leakage can cause life-threatening acute lung injury (ALI), which is characterized by inflammation, increased vascular permeability, pulmonary oedema and oxidative stress. Although the downregulation of neuronal precursor cell-expressed developmentally downregulated 4 (NEDD4) is known to be associated with inflammation and oxidative damage, its functions in phosgene-induced ALI remain unclear. In this study, rats with phosgene-induced ALI were intravenously injected with NEDD4-overexpressing lentiviruses to determine the functions of NEDD4 in this inflammatory condition. NEDD4 expression was decreased in the lung parenchyma of phosgene-exposed control rats, whereas its expression level was high in the NEDD4-overexpressing rats. Phosgene exposure increased the wet-to-dry lung weight ratio, but NEDD4 abrogated this effect. NEDD4 overexpression attenuated phosgene-induced lung inflammation, lowering the high lung injury score (based on total protein, inflammatory cells and inflammatory factors in bronchoalveolar lavage fluid) and also reduced phosgene-induced oxidative stress and cell apoptosis. Finally, NEDD4 was found to interact with Notch1, enhancing its ubiquitination and thereby its degradation, thus attenuating the inflammatory responses to ALI. Therefore, we demonstrated that NEDD4 plays a protective role in alleviating phosgene-induced ALI, suggesting that enhancing the effect of NEDD4 may be a new approach for treating phosgene-induced ALI.


Assuntos
Lesão Pulmonar Aguda , Ubiquitina-Proteína Ligases Nedd4 , Fosgênio , Receptor Notch1 , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/metabolismo , Animais , Líquido da Lavagem Broncoalveolar , Inflamação/metabolismo , Pulmão/metabolismo , Ubiquitina-Proteína Ligases Nedd4/genética , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Fosgênio/toxicidade , Ratos , Ratos Sprague-Dawley , Receptor Notch1/genética , Receptor Notch1/metabolismo
6.
J Biochem Mol Toxicol ; 35(9): e22851, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34331784

RESUMO

Phosgene may induce acute lung injury (ALI) when a person is exposed to it. Mesenchymal stem cells (MSCs) were affirmed to have therapeutic effects on phosgene-induced ALI. In a previous study, ALI exosomes have been confirmed to promote the proliferation and migration of MSCs. However, the mechanism of this phenomenon is still unclear. MicroRNAs (miRNAs) are essential in the physiological process of cells. In this study, lung-derived exosomes were isolated from phosgene-exposed and normal rats, respectively, through ultracentrifugation and cultured MSCs with these exosomes. We found that rno-miR-34c-3p was downregulated in MSCs cocultured with ALI exosomes. MiR-34c-3p inhibitor promoted the proliferation and migration of MSCs. Moreover, the dual-luciferase reporter assay demonstrated that miR-34c-3p regulated Janus kinase 1 (JAK1) expression. The miR-34c-3p inhibitor also significantly activated the JAK1/signal transducer and activator of transcription 3 (STAT3) signaling pathway. In conclusion, ALI exosomes decrease the miR-34c-3p expression levels, influencing MSCs via the JAK1/STAT3 signaling pathway.


Assuntos
Exossomos/metabolismo , Lesão Pulmonar/metabolismo , Pulmão/metabolismo , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Fosgênio/toxicidade , Animais , Técnicas de Cocultura , Exossomos/patologia , Pulmão/patologia , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/patologia , Masculino , Células-Tronco Mesenquimais/patologia , Ratos , Ratos Sprague-Dawley
7.
Dig Dis Sci ; 66(5): 1400-1408, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32591966

RESUMO

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides and play important roles in a variety of diseases. LncRNAs are involved in many biologic processes including cell differentiation, development, and apoptosis. The intestinal barrier is considered one of the most important protective barriers in humans. Severe damage or dysfunction of the intestinal barrier may be associated with the occurrence and development of many diseases, such as inflammatory bowel disease and ulcerative colitis. LncRNAs have been found to be associated with intestinal barrier function in some studies, which are at an early stage. In this review, we introduce the roles of LncRNAs in the intestinal barrier and investigate the possibility of lncRNAs as a research field in the intestinal barrier.


Assuntos
Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Regulação da Expressão Gênica , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/fisiopatologia , Mucosa Intestinal/fisiopatologia , Permeabilidade , RNA Longo não Codificante/genética
8.
BMC Neurol ; 20(1): 399, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33138778

RESUMO

BACKGROUND: Recent studies regarding the effects of erythropoietin (EPO) for treating traumatic brain injury (TBI) have been inconsistent. This study conducts a meta-analysis of randomized controlled trials (RCTs) to assess the safety and efficacy of EPO for TBI patients at various follow-up time points. METHODS: A literature search was performed using PubMed, Web of Science, MEDLINE, Embase, Google Scholar and the Cochrane Library for RCTs studying EPO in TBI patients published through March 2019. Non-English manuscripts and non-human studies were excluded. The assessed outcomes include mortality, neurological recovery and associated adverse effects. Dichotomous variables are presented as risk ratios (RR) with a 95% confidence interval (CI). RESULTS: A total of seven RCTs involving 1197 TBI patients (611 treated with EPO, 586 treated with placebo) were included in this study. Compared to the placebo arm, treatment with EPO did not improve acute hospital mortality or short-term mortality. However, there was a significant improvement in mid-term (6 months) follow-up survival rates. EPO administration was not associated with neurological function improvement. Regarding adverse effects, EPO treatment did not increase the incidence of thromboembolic events or other associated adverse events. CONCLUSIONS: This meta-analysis indicates a slight mortality benefit for TBI patients treated with EPO at mid-term follow-up. EPO does not improve in-hospital mortality, nor does it increase adverse events including thrombotic, cardiovascular and other associated complications. Our analysis did not demonstrate a significant beneficial effect of EPO intervention on the recovery of neurological function. Future RCTs are required to further characterize the use of EPO in TBI.


Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Eritropoetina/administração & dosagem , Adulto , Humanos , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Environ Sci Technol ; 54(1): 537-549, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31830789

RESUMO

A novel and efficient 3D biohybrid photocatalyst, defective MoS2 nanosheets encapsulated carbonized rape pollen, was fabricated and applied to water disinfection. The rape pollen-MoS2 (PM) biohybrid showed excellent dispersibility, high stability, and efficient charge-carrier separation and migration ability, resulting in the highly enhanced photocatalytic inactivation performance toward various waterborne bacteria under different light sources. The inactivation mechanisms were systematically investigated. Reactive species (RSs), including electrons, holes, and reactive oxygen species (•O2- and •OH), played major roles in inactivating bacteria. The antioxidant system of bacteria exhibited a self-protection capacity by eliminating the photogenerated RSs from PM biohybrid at the early stage of inactivation. With the accumulation of RSs, the cell membrane and membrane-associated functions were destroyed, as suggested by the collapse of cell envelope and subsequent loss of cell respiration and ATP synthesis capacity. The microscopic images further confirmed the destruction of the bacterial membrane. After losing the membrane barrier, the oxidation of cytoplasmic proteins and lipids caused by invaded RSs occurred readily. Finally, the leakage of DNA and RNA announced the irreversible death of bacteria. These results indicated that the bacterial inactivation began with the membrane rupture, followed by the oxidation and leakage of intracellular substances. This work not only provided a new insight into the combination of semiconductors with earth-abundant biomaterials for fabricating high-performance photocatalysts, but also revealed the underlying mechanisms of photocatalytic bacterial inactivation in depth.


Assuntos
Molibdênio , Bactérias , Brassica napus , Catálise , Luz , Pólen
10.
Environ Sci Technol ; 52(8): 4774-4784, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29578698

RESUMO

Ultrathin hydrothermal carbonation carbon (HTCC)-coated cobalt ferrite (CoFe2O4) composites with HTCC coating thicknesses between 0.62 and 4.38 nm were fabricated as novel, efficient, and magnetically recyclable photocatalysts via a facile, green approach. The CoFe2O4/HTCC composites showed high magnetization and low coercivity, which favored magnetic separation for reuse. The results show that the close coating of HTCC on CoFe2O4 nanoparticles enhanced electron transfer and charge separation, leading to a significant improvement in photocatalytic efficiency. The composites exhibited superior photocatalytic inactivation toward Escherichia coli K-12 under visible-light irradiation, with the complete inactivation of 7 log10 cfu·mL-1 of bacterial cells within 60 min. The destruction of bacterial cell membranes was monitored by field-effect scanning electron microscopy analysis and fluorescence microscopic images. The bacterial inactivation mechanism was investigated in a scavenger study, and •O2, H2O2, and h+ were identified as the major reactive species for bacterial inactivation. Multiple cycle runs revealed that these composites had excellent stability and reusability. In addition, the composites showed good photocatalytic bacterial inactivation performance in authentic water matrices such as surface water samples and secondarily treated sewage effluents. The results of this work indicate that CoFe2O4/HTCC composites have great potential in large-scale photocatalytic disinfection operations.


Assuntos
Escherichia coli K12 , Nanopartículas , Carbono , Catálise , Cobalto , Compostos Férricos , Peróxido de Hidrogênio
11.
Nanotechnology ; 28(11): 115708, 2017 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-28211366

RESUMO

Novel hierarchical NiS2 hollow spheres modified by graphite-like carbon nitride were prepared using a facile L-cysteine-assisted solvothermal route. The NiS2/g-C3N4 composites exhibited excellent photocatalytic efficiency in rhodamine B, methyl orange and ciprofloxacin degradation as compared to single g-C3N4 and NiS2, which could be due to the synergistic effects of the unique hollow sphere-like structure, strong visible-light absorption and increased separation rate of the photoinduced electron-hole pairs at the intimate interface of heterojunctions. A suitable combination of g-C3N4 with NiS2 showed the best photocatalytic performance. In addition, an electron spin resonance and trapping experiment demonstrated that the photogenerated hydroxyl radicals and superoxide radicals were the two main photoactive species in photocatalysis. A possible photocatalytic mechanism of NiS2/g-C3N4 composites under visible light irradiation is also proposed. The strategy presented here can be extended to a general strategy for constructing 3D/2D heterostructured photocatalysts for broad applications in photocatalysis.

12.
Crit Care ; 20(1): 124, 2016 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-27156867

RESUMO

BACKGROUND: Septic shock is a major healthcare problem with a high mortality rate that might be caused by immunosuppression. Programmed cell death receptor-1 (PD-1) and programmed cell death receptor ligand-1 (PD-L1), which are co-inhibitory receptor molecules, participate in sepsis-induced immunosuppression. In this study, we investigated which PD-1-related molecules can be used to evaluate the risk stratification and prognosis of septic patients. Furthermore, we explored the prognostic significance of a combination of ideal predictors and conventional clinical risk parameters in septic shock patients. METHODS: In total, 29 healthy controls, 59 septic patients, and 76 septic shock patients were enrolled in this study. Considering that the focus of the research was on the second phase of sepsis, blood samples were obtained at days 3-4 after the onset of systemic inflammatory response syndrome (SIRS). PD-1 and PD-L1 expression were measured on circulating CD4(+) T cells, CD8(+) T cells, and monocytes (PD-L1 only) by flow cytometry. RESULTS: Our results showed that only monocyte PD-L1 expression gradually increased, based on the increasing severity of disease (P < 0.001). Similarly, multivariate logistic regression analysis showed that only monocyte PD-L1 expression was an independent predictor of 28-day mortality in septic shock patients. Area under the receiver operating characteristic curve analysis of the combination of monocyte PD-L1 expression and conventional clinical risk parameters indicated a more significant prognostic ability than analysis of each parameter alone. CONCLUSION: Our study demonstrated that, among PD-1-related molecules, only monocyte PD-L1 expression after 3-4 days of sepsis was associated with risk stratification and mortality in septic patients. Furthermore, measurement of monocyte PD-L1 expression was a promising independent prognostic marker for septic shock patients.


Assuntos
Biomarcadores/sangue , Receptor de Morte Celular Programada 1/metabolismo , Sepse/mortalidade , Idoso , Antígeno B7-H1/análise , Biomarcadores/análise , Estudos de Coortes , Feminino , Humanos , Masculino , Prognóstico , Receptor de Morte Celular Programada 1/análise , Estudos Prospectivos , Sepse/metabolismo , Sepse/terapia , Choque Séptico/metabolismo , Choque Séptico/mortalidade , Choque Séptico/terapia
14.
Phys Chem Chem Phys ; 17(4): 2550-9, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25493638

RESUMO

Ag nanoparticles (NPs) are successfully grown in situ on nanoporous Fe2O3 microboxes (Ag/Fe2O3) simply by annealing Prussian blue (PB) in the presence of silver nitrate for the first time. The catalytic activity of the Ag/Fe2O3 microboxes for the reduction of p-nitrophenol (PNP) with NaBH4 is measured by UV-vis spectroscopy. It is found that the composites exhibit bifunctional properties with high magnetization and excellent catalytic activity toward PNP reduction. The high catalytic activity of the catalyst might be attributed to its high surface area and the synergistic effect on the delivery of electrons between Ag NPs and Fe2O3 microboxes. In addition, efficient reduction is observed and found to depend upon the content of Ag in the Ag/Fe2O3 microboxes. The dosage of the catalyst and the reaction temperature were investigated. Furthermore, the catalysts can be easily recycled by applying an external magnetic field while maintaining the catalytic activity without significant decrease even after running six times. The unique properties provide an ideal platform to study various metal/Fe2O3 catalysts which can be potentially applied in a wide variety of fields of catalysis and green chemistry.

15.
J Nanosci Nanotechnol ; 15(12): 9834-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26682421

RESUMO

Capsaicin is recognized as a natural tumor preventive compound and exhibits a remarkable anticancer action. Strong inhibitory role of capsaicin on gliomas has been well documented. However, the use of capsaicin is limited due to its hydrophobicity, low affinity, and short half-life. The present study aimed to explore the physiochemical characteristics of the capsaicin-loading nanoparticles prepared by methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) amphiphilic block copolymer. It also aimed to evaluate the ability of the nanoparticles to cross the blood-brain barrier. Additionally, the uptake of nanoparticles in the glioma cells and its ability to inhibit cell proliferation were tested in human glioblastoma U251 cells. mPEG-PCL amphiphilic block copolymer was synthesized using the ring-opening polymerization method, and the capsaicin-loading nanoparticles were prepared with the solvent diffusion method. In vitro drug release assay revealed that the capsaicin-loading nanoparticles presented a slow-release characteristic. Coculture of the human glioblastoma U251 cells and the fluorescein-loading nanoparticles showed the uptake of nanoparticles in U251 cells by endocytosis. We found that the NIR-797 isothiocyanate-loading nanoparticles can cross the blood-brain barrier. In addition, the capsaicin-loading nanoparticle showed a remarkable inhibition on the growth of U251 cells. The efficacy of the capsaicin-loading nanoparticles against tumor cells was significantly superior to the capsaicin at low concentrations. It is concluded that the capsaicin-loading nanoparticles can provide an extremely promising approach for chemotherapy of gliomas.


Assuntos
Capsaicina/farmacologia , Portadores de Fármacos/química , Glioma/tratamento farmacológico , Nanopartículas/química , Linhagem Celular Tumoral , Liberação Controlada de Fármacos , Glioblastoma/tratamento farmacológico , Humanos , Tamanho da Partícula , Poliésteres/química , Polietilenoglicóis/química
16.
Nanomicro Lett ; 16(1): 64, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38175306

RESUMO

Carbon dioxide conversion into valuable products using photocatalysis and electrocatalysis is an effective approach to mitigate global environmental issues and the energy shortages. Among the materials utilized for catalytic reduction of CO2, Cu-based materials are highly advantageous owing to their widespread availability, cost-effectiveness, and environmental sustainability. Furthermore, Cu-based materials demonstrate interesting abilities in the adsorption and activation of carbon dioxide, allowing the formation of C2+ compounds through C-C coupling process. Herein, the basic principles of photocatalytic CO2 reduction reactions (PCO2RR) and electrocatalytic CO2 reduction reaction (ECO2RR) and the pathways for the generation C2+ products are introduced. This review categorizes Cu-based materials into different groups including Cu metal, Cu oxides, Cu alloys, and Cu SACs, Cu heterojunctions based on their catalytic applications. The relationship between the Cu surfaces and their efficiency in both PCO2RR and ECO2RR is emphasized. Through a review of recent studies on PCO2RR and ECO2RR using Cu-based catalysts, the focus is on understanding the underlying reasons for the enhanced selectivity toward C2+ products. Finally, the opportunities and challenges associated with Cu-based materials in the CO2 catalytic reduction applications are presented, along with research directions that can guide for the design of highly active and selective Cu-based materials for CO2 reduction processes in the future.

17.
Water Environ Res ; 96(2): e10994, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38351362

RESUMO

This study aimed to improve anaerobic digestion (AD) efficiency through the addition of zero-valent iron (ZVI) and biogas slurry. This paper demonstrated that methane production was most effectively promoted at a biogas slurry reflux ratio of 60%. The introduction of ZVI into anaerobic systems does not enhance its bioavailability. However, both biogas slurry reflux and the combination of ZVI with biogas slurry reflux increase the relative abundance of microorganisms involved in the direct interspecific electron transfer (DIET) process. Among them, the dominant microorganisms Methanosaeta, Methanobacterium, Methanobrevibacter, and Methanolinea accounted for over 60% of the total methanogenic archaea. The Tax4Fun function prediction results indicate that biogas slurry reflux and the combination of ZVI with biogas slurry reflux can increase the content of key enzymes in the acetotrophic and hydrotrophic methanogenesis pathways, thereby strengthening these pathways. The corrosion of ZVI promotes hydrogen production, and the biogas slurry reflux provided additional alkaline and anaerobic microorganisms for the anaerobic system. Their synergistic effect promoted the growth of hydrotrophic methanogens and improved the activities of various enzymes in the hydrolysis and acidification phases, enhanced the system's buffer capacity, and prevented secondary environmental pollution. PRACTITIONER POINTS: Optimal methane production was achieved at a biogas slurry reflux ratio of 60%. Biogas slurry reflux in anaerobic digestion substantially reduced discharge. ZVI addition in combination with biogas slurry reflux facilitates the DIET process.


Assuntos
Ferro , Esgotos , Anaerobiose , Esgotos/microbiologia , Biocombustíveis , Metano/metabolismo , Reatores Biológicos
18.
Adv Mater ; 36(1): e2303287, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37973198

RESUMO

To alleviate the greenhouse effect and address the related energy crisis, solar-driven reduction of carbon dioxide (CO2 ) to value-added products is considered as a sustainable strategy. However, the insufficient separation and rapid recombination of photogenerated charge carriers during photocatalysis greatly limit their reduction efficiency and practical application potential. Here, isolated Cobalt (Co) atoms are successfully decorated into oxygen-doped boron nitride (BN) via an in situ pyrolysis method, achieving greatly improved catalytic activity and selectivity to the carbon monoxide (CO) product. X-ray absorption fine spectroscopy demonstrates that the isolated Co atoms are stabilized by the O and N atoms with an unsaturated CoO2 N1 configuration. Further experimental investigation and theoretical simulations confirm that the decorated Co atoms not only work as the real active center during the CO2 reduction process, but also perform as the electron pump to promote the electron/hole separation and transfer, resulting in greatly accelerated reaction kinetics and improved activity. In addition, the CoO2 N1 coordination geometry is favorable to the conversion from *CO2 to *COOH, which shall be considered as a selectivity-determining step for the evolution of the CO products. The surface modulation strategy at the atomic level opens a new avenue for regulating the reaction kinetics for photocatalytic CO2 reduction.

19.
Adv Mater ; 36(9): e2309199, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38011897

RESUMO

Although S-scheme artificial photosynthesis shows promise for photocatalytic hydrogen production, traditional methods often overly concentrate on a single reduction site. This limitation results in inadequate redox capability and inefficient charge separation, which hampers the efficiency of the photocatalytic hydrogen evolution reaction. To overcome this limitation, a double S-scheme system is proposed that leverages dual reduction sites, thereby preserving energetic photo-electrons and holes to enhance apparent quantum efficiency. The design features a double S-scheme junction consisting of CdS nanospheres decorated with anatase TiO2 nanoparticles coupled with graphitic C3 N4 . The as-prepared catalyst exhibits a hydrogen evolution rate of 26.84 mmol g-1  h-1 and an apparent quantum efficiency of 40.2% at 365 nm. This enhanced photocatalytic hydrogen evolution is ascribed to the efficient charge separation and transport induced by the double S-scheme. Both theoretical calculations and comprehensive spectroscopy tests (both in situ and ex situ) affirm the efficient charge transport across the catalyst interface. Moreover, substituting the reduction-type catalyst CdS with other similar sulfides like ZnIn2 S4 , ZnS, MoS2 and In2 S3 further confirms the feasibility of the proposed double S-scheme configuration. The findings provide a pathway to designing more effective double S-scheme artificial photosynthetic systems, opening up fresh perspectives in enhancing photocatalytic hydrogen evolution performance.

20.
Phys Chem Chem Phys ; 15(38): 15995-6000, 2013 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-23959057

RESUMO

Plasmonic heating to trigger release of oligonucleotides from nanoconjugates is potentially useful for therapeutic purposes and designed assembly of DNA nanostructures. In the past, great controllability has been achieved by introducing distinctive absorption nanoparticle centers, where the anchoring bond (e.g., sulfur-gold bond) has been selectively broken. Instead of releasing the surface-bound duplex DNA via breakage of the gold-sulphur anchor bond, selective and non-destructive dehybridization of DNA under a "mild" condition on different gold nanoconjugates is demonstrated in this work. This finding will permit sequential dehybridization/release of DNA at specific regions of a complex system; thus it can be extended to control gene expression and to manipulate an assembly of highly organized DNA constructs. Particularly we show herein the feasibility of selectively dehybridizing DNA-Au nanoconjugates via localized plasmonic heating, which is accomplished by controlling the laser wavelength, power, and irradiation time.


Assuntos
Ouro/química , Lasers , Nanoconjugados/química , Oligonucleotídeos/química , Sequência de Bases , Carbocianinas/química , Hibridização de Ácido Nucleico , Espectrometria de Fluorescência
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