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Heteroatom-doped layered porous carbons are recently regarded as promising electrode materials for high energy density supercapacitors because they can integrate high-level heteroatom-doping and layered nano-space together to provide huge pseudocapacitive reaction areas and accelerate ion diffusion/transport. Herein, an innovative strategy is reported to prepare N/B/O co-doped layered porous carbons via ammonium folate-reinforced self-assembly of gelatin and boric acid followed by carbonization. Biomass-derived ammonium folate not only acts as an N-riched precursor but also can fasten in the process of self-assembly via boric acid-assisted electrostatic adsorption and hydrogen bonding to promote the formation of stable 3D cross-linked networks, resulting in the obtained N/B/O co-doped layered porous carbon (BNLC-850) has a large specific surface area (1822 m2 g-1 ), hierarchical porous structure and super-high heteroatom contents (N, 12.65; B, 5.67; and O, 13.84 at.%). The BNLC-850 achieves an ultrahigh specific capacitance of 525.2 F g-1 in the alkaline electrolyte at 0.5 A g-1 , meanwhile, DFT calculations reveal that the high-level N/B/O-doping can effectively weaken the adsorption barriers of K-ions. Moreover, the BNLC-850 assembles anti-freezing flexible solid-state supercapacitors in MPEI-TF-IL gel polymer electrolyte deliver a high energy density of 41.2 Wh kg-1 , excellent flexibility, and long cycle-life at -20 °C.
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Cyano-rich g-C3 N4 materials are widely used in various fields of photochemistry due to the very powerful electron-absorbing ability and electron storage function of cyano, as well as its advantages in improving light absorption, adjusting the energy band structure, increasing the polarization rate and electron density in the structure, active site concentration, and promoting oxygen activation ability. Notwithstanding, there is yet a huge knowledge break in the design, preparation, detection, application, and prospect of cyano-rich g-C3 N4 . Accordingly, an overall review is arranged to substantially comprehend the research progress and position of cyano-rich g-C3 N4 materials. An overall overview of the current research position in the synthesis, characterization (determination of their location and quantity), application, and reaction mechanism analysis of cyano-rich g-C3 N4 materials to provide a quantity of novel suggestions for cyano-modified carbon nitride materials' construction is provided. In view of the prevailing challenges and outlooks of cyano-rich g-C3 N4 materials, this paper will purify the growth direction of cyano-rich g-C3 N4 , to achieve a more in-depth exploration and broaden the applications of cyano-rich g-C3 N4 .
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The ethanol oxidation reaction (EOR) is an attractive alternative to the sluggish oxygen evolution reaction in electrochemical hydrogen evolution cells. However, the development of high-performance bifunctional electrocatalysts for both EOR and hydrogen evolution reaction (HER) is a major challenge. Herein, the synthesis of Pd3 Pb@Pt core-shell nanocubes with controlled shell thickness by Pt-seeded epitaxial growth on intermetallic Pd3 Pb cores is reported. The lattice mismatch between the Pd3 Pb core and the Pt shell leads to the expansion of the Pt lattice. The synergistic effects between the tensile strain and the core-shell structures result in excellent electrocatalytic performance of Pd3 Pb@Pt catalysts for both EOR and HER. In particular, Pd3 Pb@Pt with three Pt atomic layers shows a mass activity of 8.60 A mg-1 Pd+Pt for ethanol upgrading to acetic acid and close to 100% of Faradic efficiency for HER. An EOR/HER electrolysis system is assembled using Pd3 Pb@Pt for both the anode and cathode, and it is shown that low cell voltage of 0.75 V is required to reach a current density of 10 mA cm-2 . The present work offers a promising strategy for the development of bifunctional catalysts for hybrid electrocatalytic reactions and beyond.
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The crystal plane effect has gained extensive attention in heterogeneous catalysis reactions; however, it is far from being systematically probed in titanium dioxide (TiO2)-supported vanadium catalysts. Herein, a series of vanadium (V) single atoms and clusters anchored on TiO2 with different crystal planes was fabricated by an improved "top-down" protocol. The dispersion state, electronic structure, and redox properties of the V single-atom and VOx cluster-supported catalysts were systematically analyzed by a series of characterization methods, including X-ray absorption near edge structure (XANES) and density functional theory (DFT) calculations, and their catalytic performances were examined for aerobic oxidative desulfurization (AODS) of 4,6-dimethyl-dibenzothiophen (4,6-DMDBT) with O2 as the oxidant. The results unveiled that the synergistic effect between the V single atom and the VOx cluster perceptibly promoted the catalytic performances of VOx/TiO2 samples. Therein, VOx/TiO2-(001) shows the lowest apparent activation energy (Ea) value of 46.3 kJ/mol and the optimal AODS performance with complete 4,6-DMDBT conversion to 4,6-dimethyldibenzothiophene sulfone (4,6-DMDBTO2) within 60 min at 120 °C as compared with VOx/TiO2-(101) (81.9 kJ/mol and 180 min) and VOx/TiO2-(100) (68.0 kJ/mol and 240 min), which should be attributed to its higher V5+/V4+ ratio, the optimal redox behavior of the V species, the moderate adsorption energy between 4,6-DMDBT and VOx active centers, and the synthetic effect of V single atoms and VOx clusters. Moreover, VOx/TiO2-(001) exhibits robust durability in seven cycles of reuse, showcasing the potential for practical applications in the future.
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Largemouth bass ranavirus (LMBV) is an epidemic disease that seriously jeopardizes the culture of largemouth bassï¼Micropterus salmoidesï¼, and it has a very high incidence in largemouth bass. Once an outbreak occurs, it may directly lead to the failure of the culture, resulting in substantial economic losses, but there is no effective vaccine or special effective drug yet. Consequently, it is important to establish an accurate, sensitive, convenient and specific detection approach for preventing LMBV infection. The recombinant enzyme-assisted amplification (RAA) technology was used in combination with clustered regularly interspaced short palindromic repeats (CRISPR), and associated protein 13a (CRISPR/Cas13a) to detect LMBV. We designed RAA primers and CRISPR RNA (crRNA) that targeted the conserved region in the LMBV main capsid protein (MCP) gene, amplified sample nucleic acids using the RAA technology, performed CRISPR/Cas13a fluorescence detection and evaluated the sensitivity and specificity of the established method with qPCR as a control method. This technique was able to determine the results by collecting fluorescence signals, visualizing fluorescence by UV excitation and combining with lateral flow strips (LFS). The sensitivity and specificity of the established method were consistent with the qPCR method. Besides, it was performed at a constant temperature of 37 °C and the sensitivity of the reaction system was 3.1 × 101 copies/µL, with no cross-reactivity with other common aquatic pathogens. Further, the positive detection rate of the proposed method in 32 clinical samples was consistent with that of qPCR. In conclusion, our established RAA-CRISPR/Cas13 method for detecting LMBV is sensitive, simple and specific, which is applicable in the rapid on-site detection and epidemiological monitoring of LMBV.
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Bass , Infecções por Vírus de DNA , Doenças dos Peixes , Ranavirus , Animais , Proteínas do CapsídeoRESUMO
Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi4O5Br2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi4O5Br2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO2 and Cr(VI) reduction. Specifically, CuTCPP/Bi4O5Br2-2 achieves a CO generation rate of 17.14 µmol g-1 under 5 h irradiation, which is twice as high as that of Bi4O5Br2 (8.57 µmol g-1). Besides, the optimized CuTCPP/Bi4O5Br2-2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.
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Pulmonary hypertension (PH) is a disease characterized by advanced pulmonary vasculature remodeling that is thought to be curable only through lung transplantation. The application of angiogenic hepatocyte growth factor (HGF) is reported to be protective in PH through its anti-vascular remodeling effect, but excessive HGF-mediated immature neovascularization is not conducive to the restoration of pulmonary perfusion because of apparent vascular leakage. As a canonical antiangiogenic molecule, pigment epithelium-derived factor (PEDF) inhibits angiogenesis and reduces vascular permeability in a variety of diseases. However, the effect of PEDF on HGF-based PH treatment remains to be determined. In this study, monocrotaline-induced PH rats and endothelial cells isolated from rat and human PH lung tissues were used. We assessed PH progression, right cardiac function, and pulmonary perfusion in HGF- and/or PEDF-treated rats with PH. Additionally, the receptor and mechanism responsible for the role of PEDF in HGF-based PH therapy were investigated. In this study, we found that HGF and PEDF jointly prevent PH development and improve right cardiac function in rats with PH. Moreover, PEDF delivery increases the pulmonary perfusion in PH lungs and inhibits immature angiogenesis and vascular endothelial (VE)-cadherin junction disintegration induced by HGF without affecting the therapeutic inhibition of pulmonary vascular remodeling by HGF. Mechanistically, PEDF targets VE growth factor receptor 2 and suppresses its phosphorylation at Y951 and Y1175 but not Y1214. Finally, VE growth factor receptor 2/VE protein tyrosine phosphatase/VE-cadherin complex formation and Akt and Erk1/2 inactivation were observed in rat and human PH lung endothelial cells. Collectively, our data indicate that PEDF additively enhances the efficacy of HGF against PH, which may provide new insights into treatment strategies for clinical PH.
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Hipertensão Pulmonar , Serpinas , Ratos , Humanos , Animais , Fator de Crescimento de Hepatócito/efeitos adversos , Fator de Crescimento de Hepatócito/metabolismo , Hipertensão Pulmonar/metabolismo , Células Endoteliais/metabolismo , Proteínas do Olho/farmacologia , Proteínas do Olho/metabolismo , Serpinas/farmacologia , Serpinas/metabolismoRESUMO
P-block metals have gradually been utilized to synthesize non-noble-metal catalysts for oxygen reduction reaction (ORR) due to the easily tunable localized p-orbitals and resulted versatile electronic structures. The high-density single-atom bismuth sites (Bi-NC) anchored onto nitrogen-doped three-dimensional porous carbon are proved to possess significant electrocatalytic ORR performance. Theoretical calculations unveil positively charged bismuth centers prominently improved the adsorption capacity of N-doped carbon to O2 . The p orbitals of Bi sites within Bi-NC easily generate hybrid states with p orbitals of O2 , thus promoting charge transfer and ultimately reducing the energy barrier of ORR. Benefiting from p-orbital electrons regulation of bismuth atoms, Bi-NC exhibit ORR half-wave potential of 0.86 V (vs RHE). Additionally, both liquid and quasi-solid zinc-air batteries with Bi-NC as air-cathodes achieve higher power density and specific capacity than 20 wt% Pt/C, and comparable stability and round-trip efficiency with 20 wt% Pt/C. The discovery sheds light on the theoretical and practical guidance for p-block metallic single-atom catalysts.
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Single-atom adsorbents (SAAs) featuring maximized atom utilization and uniform isolated adsorption sites have aroused extensive research interest in recent years as a novel class of adsorption materials research. Nevertheless, it is still challenging to gain a fundamental understanding of the complicated behaviors of SAAs for adsorbing thiophenic compounds (THs). Herein, this work systematically investigated the mechanisms of adsorption desulfurization (ADS) over a single group IIIA metal atom (Ga, In, and Tl) anchored on hexagonal boron nitride nanosheets (BNNSs) via density functional theory (DFT) calculations. First, all the possible doping sites have been considered and their stabilities have been evaluated by the doped energy. DFT calculations reveal that metal atoms prefer to substitute B atoms on BNNSs rather than N atoms. Additionally, SAAs all exhibit considerably enhanced adsorption capacity for THs primarily by the sulfur-metal (S-M) bond with π-π interactions maintained. Among them, In-atom-based SAAs would be adequate to provide the highest adsorption energy (In_cen_B, -40.1 kcal mol-1). Furthermore, from the perspective of adsorption energy, the SAAs show superior selectivity to THs than aromatic compounds due to the newly formed S-M bond. We hope that our work will manifest the design and application of SAAs in the field of ADS and shed light on a new strategy for fabricating SAAs based on BNNSs.
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The development of an efficient and low-cost electrocatalyst for oxygen evolution reaction (OER) is the key to improving the overall efficiency of water electrolysis. Here, we report the design of a three-dimensional (3-D) heterostructured Ni9S8/Ni3S2 precatalyst composed of unstable Ni9S8 and inert Ni3S2 components, which undergoes in situ electrochemical activation to generate an amorphous-NiOOH/Ni3S2 heterostructured catalyst. In situ Raman spectroscopy combined with ex situ characterizations, such as X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy, reveals that during the activation, Ni9S8 loses the sulfur element to form nickel oxides and eventually transforms to amorphous NiOOH at O2-evolving potentials, while the Ni3S2 component is rather inert that its majority in the bulk remains, thus forming a 3-D congee-like NiOOH/Ni3S2 heterostructure with the Ni3S2 crystalline particles randomly dispersed among amorphous NiOOH species. Unlike the sparse heterostructure that consists of a layer of NiOOH on top of Ni3S2, our unique congee-like NiOOH/Ni3S2 heterostructure provides plentiful reactive amorphous-crystalline interfacial sites. Moreover, the partial electron transfer between the NiOOH and remaining Ni3S2, benefiting from their dense interfacial sites, contributes to a higher valence state of the Ni3+ active centers in NiOOH, hence optimizing the adsorption of OER intermediates. Density functional theory calculations further disclose that the electronic structure regulation not only optimizes the Gibbs free energy of intermediate adsorption but also tunes the OH* absorption behavior to be exothermic, elucidating the spontaneous occurrence of OH* absorption and hence improves the OER. Therefore, a low overpotential of only 197 mV at an O2-evolving current density of 10 mA/cm2, a small Tafel slope of 38.8 mV/dec, and good stability are achieved on the amorphous-NiOOH/crystalline-Ni3S2 heterostructured catalyst.
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The development of efficient and stable bifunctional electrocatalysts based on non-noble metals for water electrolysis is both urgent and challenging. However, unresolved issues remain regarding the challenge of identifying the active phase and gaining a comprehensive understanding of its surface reconstruction and functionality throughout the reaction process. In this study, we have combined doping and heterostructure construction by a one-step electrodeposition and a subsequent activation treatment to synthesize Fe, V co-doped Co3O4/Co(OH)2 and Co/Co(OH)2 heterointerfaces (referred to as A-Co60Fe1.1V). These heterointerfaces, composed of Co/Co(OH)2 and Co3O4/Co(OH)2, are proposed to facilitate charge transfer process during catalysis. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the introduction of V and Fe dopants increases the valence state of Co centers in Co3O4 and Co(OH)2. Further operando Raman spectroscopy reveals that Co(OH)2 and Co3O4 with the high-valence Co centers remain stable during the hydrogen evolution reaction (HER) process. These high-valence Co centers are believed to promote the crucial water dissociation step and therefore enhance the overall HER catalysis. On the other hand, during the oxygen evolution reaction (OER), Fe, V co-doping leads to an earlier formation of the active CoOOH species, while Fe doping can further help stabilize the more reactive ß-CoOOH species instead of the less reactive γ-CoOOH. As a result, the A-Co60Fe1.1V catalyst exhibits significantly improved catalytic activity for both HER and OER that it requires low overpotentials of 51 and 250 mV, respectively, to attain a current density of 10 mA cm-2. Moreover, when utilized as both the cathode and anode in alkaline water electrolysis, the A-Co60Fe1.1V catalyst can operate at a mere 1.54 V voltage while maintaining 10 mA cm-2, surpassing the majority of non-noble metal catalysts. Remarkably, it also exhibits stability for at least 40 h at â¼100 mA cm-2.
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The exploitation of highly efficient and cost-effective selective adsorbents for adsorptive desulfurization (ADS) remains a challenge. Fortunately, single-atom adsorbents (SAAs) characterized by maximized atom utilization and atomically dispersed adsorption sites have great potential to solve this problem as an emerging class of adsorption materials. Herein, aiming at improving the efficiency of ADS performance via the economical and feasible strategy, the desirable SAAs have been fabricated by uniformly anchoring aluminum (Al) atoms on hexagonal boron nitride nanofibers (BNNF) via an in situ pyrolysis method. Remarkably, Al-BN-1.0 exhibited a superior adsorption capacity of 46.1 mg S/g adsorbent for dibenzothiophene, with a 45% increase in adsorption capacity compared to the pristine BNNF. Additionally, it demonstrated excellent adsorption of other thiophene sulfides. Moreover, the ADS mechanisms have been investigated through special adsorption experiments combined with density functional theory (DFT) calculations. It was demonstrated that the superior ADS performance and selectivity of Al-BN-1.0 originate from the sulfur-aluminum (S-Al) and π-π interactions cooperating synergistically. This work would cast light on a novel fabrication strategy for the SAAs based on the two-dimensional material with a tunable metal site configurations and densities for varied selective adsorption and separation.
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In this contribution, we rationally designed and controllably fabricated a NiMo/Al2O3-montmorillonite (3D-NiMo/Al2O3-MMT) monolithic catalyst via a 3D printing strategy with economical montmorillonite (MMT) as a binder. The catalytic performance of the resulting NiMo/Al2O3-MMT for 4,6-dimethyldibenzothiophene (4,6-DMDBT) hydrodesulfurization (HDS) was evaluated. The experimental results unveil that the 3D-NiMo/Al2O3-MMT monolithic catalyst exhibits robust stability and exceptional HDS activity with 99.2% 4,6-DMDBT conversion (residual 4 ppm of S), which is remarkably superior to that of conventional NiMo/Al2O3 (61.5%), NiMo/MMT (63.2%), and even NiMo/Al2O3-MMT (76.5%) prepared by the mechanical-mixing method. This should be ascribed to the synthetic effect between the MMT binder and the Al2O3 substrate, which effectively weakens the interaction between the Mo species and the Lewis acids on the original Al2O3 surface, thereby significantly increasing the content of reducible Mo species and considerably facilitating the formation of more highly active NiMoS phase (Type II) with optimal average stacking layers and thereafter remarkably enhancing the ultradeep HDS activity of the 3D-NiMo/Al2O3-MMT monolithic catalyst.
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The design and preparation of catalysts with both excellent stability and maximum exposure of catalytic active sites is highly desirable; however, it remains challenging in heterogeneous catalysis. Herein, a entropy-stabilized single-site Mo catalyst via a high-entropy perovskite oxide LaMn0.2Fe0.2Co0.2Ni0.2Cu0.2O3 (HEPO) with abundant mesoporous structures was initiated by a sacrificial-template strategy. The presence of electrostatic interaction between graphene oxide and metal precursors effectively inhibits the agglomeration of precursor nanoparticles in a high-temperature calcination process, thereby endowing the atomically dispersed Mo6+ coordinated with four O atoms on the defective sites of HEPO. The unique structure of single-site Mo atoms' random distribution with an atomic scale greatly enriches the oxygen vacancy and increases surface exposure of the catalytic active sites on the Mo/HEPO-SAC catalyst. As a result, the obtained Mo/HEPO-SAC exhibits robust recycling stability and ultra-high oxidation activity (turnover frequency = 3.28 × 10-2) for the catalytic removal of dibenzothiophene (DBT) with air as the oxidant, which represents the top level and is strikingly higher than the state-of-the-art oxidation desulfurization catalysts reported previously under the same or similar reaction conditions. Therefore, the finding here for the first time expands the application of single-atom Mo-supported HEPO materials into the field of ultra-deep oxidative desulfurization.
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Developing catalysts with optimized surface properties is significant for advanced catalysis. Herein, a rational architectural design is proposed to successfully synthesize yolk-shell nickel molybdate with abundant oxygen vacancies (YS-VO-NMO) via an acid-assisted defect engineering strategy. Notably, YS-VO-NMO with the yolk-shell structure shows complex nanoconfined interior space, which is beneficial to the mass transfer and active sites exposure. Moreover, the defect engineering strategy is of great importance to modulate the surface electronic structure and atomic composition, which contributes to the enrichment of oxygen vacancies. Benefiting from these features, the higher hydrogen peroxide activation is achieved by YS-VO-NMO to produce more hydroxyl radicals compared with untreated nickel molybdate. Consequently, the defect-engineered YS-VO-NMO not only features superior catalytic activity (99.5%) but also retains high desulfurization efficiency after recycling eight times. This manuscript provides new inspiration for designing more promising defective materials via defect engineering and architecture for different applications besides oxidative desulfurization.
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Achieving long-term stable deep desulfurization at room temperature and recovering high value-added sulfone products is a challenge at present. Herein, a series of catalysts [Cnmim]5VW12O40Br (CnVW12, 1-alkyl-3-methylimidazolium bromide tungstovanadate, n = 4, 8, 16) were presented for the room temperature catalytic oxidation of dibenzothiophene (DBT) and its derivatives. Factors affecting the reaction process, such as the amount of catalyst, oxidant, and temperature, were systematically discussed. C16VW12 showed higher catalytic performance, and 100% conversion and selectivity could be achieved in 50 min with only 10 mg. The mechanism study showed that the hydroxyl radical was the active radical in the reaction. Benefiting from the "polarity strategy", the sulfone product accumulated after 23 cycles in a C16VW12 system, and the yield and purity were about 84% and 100%, respectively.
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Acidic deep eutectic solvents (DESs) have been considered desirable extractants and catalysts for desulfurization. However, their hydrogen bond donors (HBDs) are usually sole organic acids, which are not conducive to efficient green catalysis. Herein, a novel inorganic-organic dual-acid DES (DADES) was reported for efficient extractive and oxidative desulfurization. Benefiting from the physical interaction among the three components in a DADES, a transparent homogeneous liquid can be obtained even though inorganic acid (boric acid, BA) and organic acid (acetic acid, AA) can be immiscible. Furthermore, the dual-acid HBD can increase the acidity of the DADES and reduce its viscosity, accelerating its mass transfer efficiency and enhancing its catalytic activity. With 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as the hydrogen bond acceptor, [Bmim]Cl/BA/0.3AA effectively activated hydrogen peroxide and achieved sulfur removal of 96.6% at 40 °C. Furthermore, the universality of the synergistic effect in various DADESs was confirmed by the modulation of the types of organic acids. This study not only motivates the construction of more intriguing novel DESs based on the DADES concept but also highlights their potential in clean fuel production.
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Objective: Accumulating evidence supports neuroprotective effects of regulatory T cells (Tregs) in response to brain injury. However, the precise mechanisms underlying the beneficial effects of Tregs on suppressing neuroinflammation after subarachnoid hemorrhage (SAH) remain unclear. Methods: We performed flow cytometry to detect the infiltration of Tregs into the brain at different time points after SAH. Behavioral tests, including Adhesive and Rotarod, were performed to assess neurological deficits in mice after SAH. Bulk RNA sequencing was used to investigate the transcriptomic change of Tregs infiltrating into the brain after SAH. qPCR was performed to verify the variation of inflammatory cytokines expression in the brain after Tregs exogenous infusion. FoxP3-DTR mice and Il10 gene KO mice were used to explore the mechanism of Tregs inhibiting neuron apoptosis after infiltrating the brain following SAH onset. Results: Peripheral Tregs infiltrated into the brain one day after SAH and gradually accumulated in the hemorrhagic hemisphere. An exogenous infusion of Tregs significantly improved the neurological function of mice after SAH, while poor recovery of neurological function was observed in Tregs depletion mice. Transcriptome sequencing data suggested that the immunosuppressive function of brain-infiltrated Tregs was significantly upregulated. qPCR showed that the expression of pro-inflammatory cytokines decreased in the brain of SAH mice after exogenous Tregs infusion. Bioinformatic analysis revealed that IL-10 and other cytokines secreted by brain-infiltrated Tregs were upregulated after SAH. Moreover, exogenous infusion of Il10 gene KO Tregs did not totally improve neurological function in SAH mice. Conclusions: Tregs infiltrated into the brain in the early stage after SAH and exerted neuroprotective effect by secreting IL-10 to suppress neuroinflammation and reduce neuron apoptosis.
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Fármacos Neuroprotetores , Hemorragia Subaracnóidea , Animais , Camundongos , Citocinas/metabolismo , Interleucina-10 , Doenças Neuroinflamatórias , Fármacos Neuroprotetores/metabolismo , Transdução de Sinais/fisiologia , Hemorragia Subaracnóidea/complicações , Linfócitos T ReguladoresRESUMO
Endowing a semiconductor with tunable edge active sites will effectively enhance catalytic performance. Herein, an edge-site-rich ordered macroporous BiOCl (BiOCl-P) with abundant dangling bonds is constructed via the colloidal crystal template method. The edge-site-rich ordered macroporous structure provides abundant adsorption sites for CO2 molecules, as well as forms numerous localized electron enrichment areas, accelerating charge transfer. DFT calculations reveal that the dangling bonds-rich configuration can effectively reduce the CO2 activation energy barrier, boost the CO double bond dissociation, and facilitate the proton electron coupling reaction. As a result, the BiOCl-P achieves a higher CO and CH4 generation rate of 78.07 and 3.03 µmol g-1 under 4 h Xe lamp irradiation in a solid-gas system. Finally, the CO2 molecules' conversion process is further investigated by in situ Fourier-transform infrared spectroscopy. This work realizes a new avenue toward the design of vibrant semiconductors on the nanoscale to boost inert CO2 photoreduction.
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Dióxido de Carbono , Semicondutores , Adsorção , Catálise , ElétronsRESUMO
Bimetallic materials have been regarded as promising catalysts for efficient alkaline water splitting. However, the spontaneous reconstruction of the surface structures of the catalysts before catalysis has long been overlooked. Here, we present that in situ dissolution of MoO42- in CoMoO4 boosts spontaneous surface reconstruction in an alkaline medium. Our results reveal that CoMoO4 microrod arrays function as precatalysts that undergo spontaneous surface reconstruction under alkaline conditions, forming a layer of Co3O4/CoMoO4 and CoOOH/CoMoO4 heterostructures. X-ray photoelectron spectroscopy (XPS) combined with in situ Raman spectroscopy reveals that in such activated CoMoO4 (A-CoMoO4), the partial electron transfer from Co to Mo sites helps induce a higher valence state of Co centers and the heterostructure of Co3O4/CoMoO4 may promote the generation of CoOOH, which is very likely the precursor to the active Co4+ species for oxygen evolution reaction (OER) catalysis. During the hydrogen evolution reaction (HER), Co3O4 generated after surface reconstruction can promote the dissociation of water, which is considered the rate-determining step of the alkaline HER. Hence, A-CoMoO4 exhibits superior bifunctional electrocatalytic activities that the overpotentials at a working current density of 10 mA cm-2 for the HER and OER are only 13 and 264 mV, respectively. Inspired by the remarkable bifunctionality, the electrolytic cell employing A-CoMoO4 as both anode and cathode shows an appealing potential of 1.51 V to deliver 10 mA cm-2 for overall water splitting. Similarly, CoVOx also shows the spontaneous surface reconstruction behavior in the alkaline medium, which we propose can be extended to a series of oxometalate catalysts.