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The incorporation of oxyanion groups offers a greater potential for enhancing the activity of oxygen evolution reaction (OER) electrocatalysts compared to traditional metal cations doping, owing to their unique configurations and high electronegativity. However, the incorporation of oxyanion groups that differ from those derived from the oxidation of anions in transition metal monoxides poses significant challenges, thereby limiting further applications of oxyanion group modification approach. Herein, we present a novel sulfate salt assistant approach to fabricate Fe-doped Ni2P modified with SO42-/carbon (Fe-Ni2P-S/C) nanofibers as highly efficient OER electrocatalyst. The optimized Fe-Ni2P-S/C nanofibers display superb OER activity, requiring low overpotentials of 266, 323, and 357 mV at 100, 500, and 1000 mA cm-2, respectively. Theoretical calculations reveal that the co-adsorption of PO43- and SO42- on the surface of reconstructed electrocatalyst can reduce the energy barrier of rate-determining step, thereby resulting in enhanced OER activity. The present study emphasizes the crucial role played by anion groups in OER activity as well as proposes a novel approach for incorporating anion groups into electrocatalysts.
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BACKGROUND: Ovarian cancer (OvCa) is the most lethal of the gynecologic malignancies. Immune checkpoint inhibitors, which have revolutionized the treatment of multiple malignancies, have had limited efficacy in OvCa patients. This lack of effectiveness is partly due to the abnormal ovarian tumor microenvironment (TME), displaying a desmoplastic, highly fibrotic extracellular matrix. High extracellular matrix deposition leads to a buildup of compressive forces that cause tumor blood vessel collapse, reduced vessel perfusion, poor delivery of drugs, and compromised trafficking of cytotoxic T-cells to these tumors. METHODS: Using two syngeneic OvCa models, we tested the effect of losartan, a widely prescribed anti-hypertensive drug, on reprogramming the TME and chemosensitizing the cancer cells. RESULTS: Losartan treatment (i) reprograms the TME leading to increased vascular perfusion, and thus enhances drug delivery and immune effector cell intratumoral infiltration and function; and (ii) rewires the OvCa cells by suppressing the IGF-1 signaling, resulting in enhanced chemosensitivity. As a result of the combined tumor and stromal effects, losartan treatment enhances the efficacy of chemo-immunotherapy in OvCa models. CONCLUSION: The safety and low cost ( < $1-2/day) of losartan warrant rapid translation of our findings to patients with OvCa.
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Defect-rich nitrogen-doped biocatalyst (B-NC) was synthesized from natural cellulose of wheat straw using straightforward mechanical method and one-step pyrolysis approach. In contrast to the nitrogen-doped biocatalyst (NC), by leveraging the synergistic effects of nitrogen dopants and surface defects, the microenvironment-modulated B-NC exhibited the enhanced mass transfer efficiency and a significant improvement in reactivity for p-nitrophenol degradation (111 %-196 %). The catalyst's exceptional performance primarily arose from graphitic N, pyridinic N and CO active sites, which mainly derived from the cellulose structure of wheat straw and nitrogen dopants. Electron paramagnetic resonance and quenching tests confirmed that the B-NC/peroxymonosulfate system generated more reactive species (SO4â¢-, â¢OH, O2â¢-, and 1O2) during p-nitrophenol degradation, surpassing the NC/peroxymonosulfate system. Additionally, both density functional theory calculations and electrochemical experiments provided evidence of peroxymonosulfate strongly adsorbing onto B-NC's defect sites, facilitating the formation of catalyst/peroxymonosulfate* complexes and promoting electron transfer processes. This research provides valuable insights into the regulation of defects in nitrogen-doped biocatalyst derived from natural cellulose, presenting a promising solution for remediating refractory organic pollutants.
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Histidine kinases (HKs) are important sensor proteins in fungi and play an essential role in environmental adaptation. However, the mechanisms by which fungi sense and respond to fungivores attack via HKs are not fully understood. In this study, we utilized Neurospora crassa to investigate the involvement of HKs in responding to fungivores attack. We found that the 11 HKs in N. crassa not only affected the growth and development, but also led to fluctuations in antioxidant production. Ten mutants in the genes encoding HKs (except ∆phy1) showed increased production of reactive oxygen species (ROS), especially upon Sinella curviseta attack. The ROS burst triggered changes in conidia and perithecial beaks formation, as well as accumulation of ß-glucan, ergothioneine, ergosterol, and carotenoids. ß-glucan was increased in ∆hk9, ∆os1, ∆hcp1, ∆nik2, ∆sln1, ∆phy1 and ∆phy2 mutants compared to the wild-type strain. In parallel, ergothioneine accumulation was improved in ∆phy1 and ∆hk16 mutants and further increased upon attack, except in ∆os1 and ∆hk16 mutants. Additionally, fungivores attack stimulated ergosterol and dehydroergosterol production in ∆hk9 and ∆os1 mutants. Furthermore, deletion of these genes altered carotenoid accumulation, with wild-type strain, ∆hk9, ∆os1, ∆hcp1, ∆sln1, ∆phy2, and ∆dcc1mutants showing an increase in carotenoids upon attack. Taken together, HKs are involved in regulating the production of conidia and antioxidants. Thus, HKs may act as sensors of fungivores attack and effectively improve the adaptive capacity of fungi to environmental stimuli.
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Histidina Quinasa , Neurospora crassa , Especies Reactivas de Oxígeno , Neurospora crassa/genética , Neurospora crassa/metabolismo , Histidina Quinasa/genética , Histidina Quinasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Esporas Fúngicas/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Animales , Regulación Fúngica de la Expresión Génica , Artrópodos/genética , Artrópodos/microbiología , Mutación , Adaptación Fisiológica/genética , Ergosterol/metabolismo , beta-Glucanos/metabolismo , Antioxidantes/metabolismo , Carotenoides/metabolismo , ErgotioneínaRESUMEN
Dry reforming of methane (DRM) to syngas is an important route to co-convert CH4 and CO2. However, the highly endothermic nature of DRM induces the thermocatalysis to commonly operate at high temperatures that inevitably causes coke deposition through pyrolysis of methane. Herein, benefiting from the mass spectrometric experiments complemented with quantum chemical calculations, we have discovered that the bimetallic oxide cluster Rh2CoO- can mediate the co-conversion of CH4 and CO2 at room temperature giving rise to two free H2 molecules and two adsorbed CO molecules (COads). The only elementary step requiring the input of external energy (e.g., high temperature) is desorption of COads from the reaction intermediate Rh2CoOC2O2-. The doping effect of Co has also been clarified that the Co could tune the charge distribution and orbital energy of the active metal Rh, enabling the enhancement of cluster reactivity toward C-H activation, which is essential to facilitating the DRM to syngas. This work not only underlines the importance of temperature control over elementary steps in practical thermocatalysis but also identifies a promising active species containing the late 3d transition metal to drive DRM to syngas. The findings could provide novel insights into design of bimetallic catalysts for co-conversion of CH4 and CO2 at low temperatures.
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Atomic oxygen radical anion (Oâ -) represents an important type of reactive centre that exists in both chemical and biological systems. Gas-phase atomic clusters can be studied under isolated and well controlled conditions. Studies of Oâ --containing clusters in the gas-phase provide a unique strategy to interpret the chemistry of Oâ - radicals at a strictly molecular level. This review summarizes the research progresses made since 2013 for the reactivity of Oâ - radicals in the atomically precise metal oxide clusters including negatively charged, nanosized, and neutral heteronuclear metal clusters benefitting from the development of advanced experimental techniques. New electronic and geometric factors to control the reactivity and product selectivity of Oâ - radicals under dark and photo-irradiation conditions have been revealed. The detailed mechanisms of Oâ - generation have been discussed for the reaction systems of nanosized and heteroatom-doped metal oxide clusters. The catalytic reactions mediated by the Oâ - radicals in metal clusters have also been successfully established and the microscopic mechanisms about the dynamic generation and depletion of Oâ - radicals have been clearly understood. The studies of Oâ - containing metal oxide clusters in the gas-phase provided new insights into the chemistry of reactive oxygen species in related condensed-phase systems.
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The multi-cationic site occupation control of rare earth doped phosphor materials is one of the key factors in achieving single-phase full-spectrum emission. In this work, the site distribution of Eu2+ in Ca9NaGd0.667(PO4)7 (CNGP):x%Eu2+ phosphors with multi-cationic sites was determined. Under 385 nm excitation, CNGP:x%Eu2+ samples exhibited a cyan emission composed of three sub-Gaussian components. The CNGP:1.5%Eu2+ phosphor was structurally modified through the partial substitution of Mg2+ for Ca2+ according to the crystallographic site engineering theory, and corresponding luminescent properties had been adjusted. When the concentration of Mg2+ changed, the Ca9-yMgyNaGd0.667(PO4)7:1.5%Eu2+ (CNGPE:yMg2+) phosphors exhibited a tunable emission from cyan to orange and achieved white light emission at y = 0.6. Based on the change of the crystal field environment, the mechanism of Mg2+ substitution affecting the luminescence characteristics of CNGP:x%Eu2+ phosphors was researched in detail. The light-emitting diode device consisted of a CNGPE:0.6Mg2+ phosphor and a 385 nm chip and had a high color rendering index (CRI = 91.9), low correlated color temperature (CCT = 4852 K), and excellent color stability. The optical performance of this device makes it promising to be used in full spectrum lighting.
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Understanding the impact of climate warming on crop yield and its associated mechanisms is paramount for ensuring food security. Here, we conduct a thorough analysis of the impact of vapor pressure deficit (VPD) on maize yield, leveraging a rich dataset comprising temporal and spatial observations spanning 40 years across 31 maize-growing locations in Northeast and North China. Our investigation extends to the influencing meteorological factors that drive changes in VPD during the maize growing phase. Regression analysis reveals a linear negative relationship between VPD and maize yield, demonstrating diverse spatiotemporal characteristics. Spatially, maize yield exhibits higher sensitivity to VPD in Northeast China (NEC), despite the higher VPD levels in North China Plain (NCP). The opposite patterns reveal that high VPD not invariably lead to detrimental yield impacts. Temporal analysis sheds light on an upward trend in VPD, with values of 0.05 and 0.02 kPa/10yr, accompanied by significant abrupt changes around 1996 in NEC and 2006 in NCP, respectively. These temporal shifts contribute to the heightened sensitivity of maize yield in both regions. Importantly, we emphasize the need to pay closer attention to the substantial the impact of actual vapor pressure on abrupt VPD changes during the maize growing phase, particularly in the context of ongoing climate warming.
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Presión de Vapor , Zea mays , Zea mays/crecimiento & desarrollo , China , Cambio Climático , Calentamiento GlobalRESUMEN
Metal oxide clusters with atomic oxygen radical anions are important model systems to study the mechanisms of activating and transforming very stable alkane molecules under ambient conditions. It is extremely challenging to characterize the activation and conversion of methane, the most stable alkane molecule, by metal oxide cluster anions due to the low reactivity of the anionic species. In this study, using a ship-lock type reactor that could be run at relatively high pressure conditions to provide a high number of collisions in ion-molecule reactions, the rate constants of the reactions between (MoO3)NO- (N = 1-21) cluster anions and the light alkanes (C1-C4) were measured under thermal collision conditions. The relationships among the reaction rates of different alkanes were obtained to establish a model to predict the low rate constants with methane from the high rate constants with C2-C4 alkanes. The model was tested by using available experimental results in literature. This study provides a new method to estimate the relatively low reactivity of atomic oxygen radical anions with methane on metal oxide clusters.
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Tabique Nasal , Humanos , Tabique Nasal/cirugía , Rinoplastia/métodos , Rinoplastia/educación , EnseñanzaRESUMEN
Metal-metal bonds constitute an important type of reactive centers for chemical transformation; however, the availability of active metal-metal bonds being capable of converting methane under mild conditions, the holy grail in catalysis, remains a serious challenge. Herein, benefiting from the systematic investigation of 36 metal clusters of tantalum by using mass spectrometric experiments complemented with quantum chemical calculations, the dehydrogenation of methane at room temperature was successfully achieved by 18 cluster species featuring σ-bonding electrons localized in single naked Ta-Ta centers. In sharp contrast, the other 18 remaining clusters, either without naked Ta-Ta σ-bond or with σ-bonding electrons delocalized over multiple Ta-Ta centers only exhibit molecular CH4-adsorption reactivity or inertness. Mechanistic studies revealed that changing cluster geometric configurations and tuning the number of simple inorganic ligands (e.g., oxygen) could flexibly manipulate the presence or absence of such a reactive Ta-Ta σ-bond. The discovery of Ta-Ta σ-type bond being able to exhibit outstanding activity toward methane conversion not only overturns the traditional recognition that only the metal-metal π- or δ-bonds of early transition metals could participate in bond activation but also opens up a new access to design of promising metal catalysts with dual-atom as reactive sites for chemical transformations.
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Dynamic covalent hydrogels are gaining attention for their potential in smart materials, soft devices, electronics, and more thanks to their impressive mechanical properties, biomimetic structures, and dynamic behavior. However, a significant challenge lies in designing precise and efficient dynamic photochemistry for their preparation, allowing for complex structures and control over the dynamic process. Herein, we propose a general and straightforward orthogonal dynamic covalent photochemistry strategy for preparing high-performance printable dynamic covalent hydrogels, thereby broadening their advanced applications. This photochemical strategy uses a bifunctional photocatalyst to initiate radical polymerization and release ligands through a rapid light-mediated dissociation mechanism. This process leads to a controlled increase in system pH from mildly acidic to alkaline conditions within one hundred seconds, which in turn triggers the pH-sensitive model reactions of boronic acid/diol complexation and Knoevenagel condensation. The orthogonal photochemistry enables the formation of interpenetrated and conjoined networks, significantly enhancing the mechanical properties of the hydrogels. The reversible bonds formed during the process, i.e., boronic ester and unsaturated ketone bonds, confer excellent self-healing, reprocessable, and recyclable properties on the hydrogels through photochemical pH variations. Furthermore, this rapid, controlled fabrication process and dynamic behavior are highly compatible with printing techniques, enabling the design of adaptive and recyclable sensors with different structures. These advancements are promising for various material science, medicine, and engineering applications.
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Cost-effective and readily accessible 3d transition metals (TMs) have been considered as promising candidates for alkane activation while 3d TMs especially the early TMs are usually not very reactive with light alkanes. In this study, the reactivity of Vn+ and VnO+ (n = 1-9) cluster cations towards ethane under thermal collision conditions has been investigated using mass spectrometry and density functional theory calculations. Among Vn+ (n = 1-9) clusters, only V3-5+ can react with C2H6 to generate dehydrogenation products and the reaction rate constants are below 10-13 cm3 molecule-1 s-1. In contrast, the reaction rate constants for all VnO+ (n = 1-9) with C2H6 significantly increase by about 2-4 orders of magnitude. Theoretical analysis evidences that the addition of ligand O affects the charge distribution of the metal centers, resulting in a significant increase in the cluster reactivity. The analysis of frontier orbitals indicates that the agostic interaction determines the size-dependent reactivity of VnO+ cluster cations. This study provides a novel approach for improving the reactivity of early 3d TMs.
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It is of great practical significance for regional sustainable development and ecological construction to quantitatively analyze the impact of construction land expansion on terrestrial ecosystem carbon storage and to explore the optimization scheme of simulating construction land expansion to improve future ecosystem carbon storage. Based on the land use and cover change (LUCC) and other geospatial data of the Beijing-Tianjin-Hebei Urban Agglomeration from 2000 to 2020, this study utilized the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and the patch-generating land-use simulation (PLUS) model to assess and analyze the changes in ecosystem carbon stocks and spatial patterns regionally. In this study, we performed linear regression analysis to investigate the relationship between urban land expansion and changes in ecosystem carbon stocks for varying urban land proportion levels during two distinct time intervals, 2000-2010 and 2010-2020, which was conducted at a spatial resolution of 2 km. Three distinct urban land expansion scenarios were subjected to simulation to forecast the prospective land use pattern by 2030. Subsequently, we quantified the ramifications of these scenarios on ecosystem carbon stocks during the period from 2020 to 2030. The results were as follows:â In the Beijing-Tianjin-Hebei Urban Agglomeration, the ecosystem carbon stocks exhibited notable variations over the study period, with values of 2 088.02, 2 106.78, and 2 121.25 Tg recorded for the years 2000, 2010, and 2020, respectively, resulting in a cumulative carbon sequestration of 33.23 Tg C during the study duration. It is noteworthy that forest carbon storage emerged as the dominant contributor, with an increase from 1 010.17 Tg in 2000 to 1 136.53 Tg in 2020. Throughout the study period, the spatial distribution of carbon stocks displayed relative stability. Regions characterized by lower carbon content were concentrated in the vicinity of the Bohai Rim region and in proximity to cities such as Beijing, Tianjin, and Shijiazhuang, as well as rural settlements. In contrast, grid units with moderate and high carbon stocks were predominantly situated in the western Taihang Mountain and the northern Yanshan Mountain. Additionally, there was a tendency of increasing carbon stocks in the Taihang Mountain and Yanshan Mountain region, whereas those surrounding major urban centers such as Beijing, Tianjin, Shijiazhuang, and Tangshan experienced a notable decline in carbon stocks. Such reductions were most pronounced in regions undergoing urban land expansion during the study period. â¡ In grid units with an urban land proportion exceeding 10% at each level, a strong correlation was observed between urban land expansion and changes in carbon stocks during both the 2000-2010 and 2010-2020 periods. The changes in urban land proportion adequately explained the variations in carbon stocks. However, the explanatory power of urban land on carbon stocks decreased during the 2010-2020 period, indicating that other factors played a more substantial role in influencing carbon stocks during this time. The regression coefficients for both periods exhibited a fluctuating upward trend. In comparison to that during the 2000-2010 period, the impact of urban land expansion on carbon stocks was relatively smaller during 2010-2020, indicating a weakening influence. ⢠In light of three distinct development scenarios, namely natural development (Scenario â ), a 15% reduction in the rate of urban land expansion (Scenario â ¡), and a 30% reduction in the rate of urban land expansion (Scenario â ¢), the projected ecosystem carbon stocks for the Beijing-Tianjin-Hebei Urban Agglomeration in the year 2030 were estimated to be 2 129.12, 2 133.55, and 2 139.10 Tg, respectively. These projections indicated an increase of 7.88, 12.30, and 17.85 Tg in comparison to the current carbon stocks. All scenarios demonstrated that the terrestrial ecosystem would play a role of carbon sink, particularly with the greatest carbon sink observed in the scenario with a 30% reduction in urban land expansion. The fit performance between urban land expansion and carbon stock changes during the 2020-2030 period was significantly better than that during the 2000-2010 and 2010-2020 periods, and the regression coefficients showed a fluctuating increase with an increase in urban land proportion. Across grid units with different urban land proportion levels, the regression coefficients exhibited the order of Scenario â < Scenario â ¡ < Scenario â ¢. In pursuit of the carbon peaking and carbon neutrality goals, the Beijing-Tianjin-Hebei Urban Agglomeration should prioritize scenarios with reduced rates of urban land expansion, especially in regions with higher urban land proportions.
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Understanding the mechanisms of C-H activation of alkanes is a very important research topic. The reactions of metal clusters with alkanes have been extensively studied to reveal the electronic features governing C-H activation, while the experimental cluster reactivity was qualitatively interpreted case by case in the literature. Herein, we prepared and mass-selected over 100 rhodium-based clusters (RhxVyOz- and RhxCoyOz-) to react with light alkanes, enabling the determination of reaction rate constants spanning six orders of magnitude. A satisfactory model being able to quantitatively describe the rate data in terms of multiple cluster electronic features (average electron occupancy of valence s orbitals, the minimum natural charge on the metal atom, cluster polarizability, and energy gap involved in the agostic interaction) has been constructed through a machine learning approach. This study demonstrates that the general mechanisms governing the very important process of C-H activation by diverse metal centers can be discovered by interpreting experimental data with artificial intelligence.
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The designing and fabricating highly active hydrogen evolution reaction (HER) electrocatalysts that can superior to Pt/C is extremely desirable but challenging. Herein, the fabrication of Ru/TiO2/N-doped carbon (Ru/TiO2/NC) nanofiber is reported as a novel and highly active HER electrocatalyst through electrospinning and subsequent pyrolysis treatment, in which Ru nanoclusters are dispersed into TiO2/NC hybrid nanofiber. As a novel support, experimental and theoretical calculation results reveal that TiO2/NC can more effectively accelerate water dissociation as well as optimize the adsorption strength of *H than TiO2 and NC, thus leading to a significantly enhanced HER activity, which merely requires an overpotential of 18 mV to reach 10 mA cm-2, outperforming Pt/C in an alkaline solution. The electrolytic cell composed of Ru/TiO2/NC nanofiber and NiFe LDH/NF can generate 500 and 1000 mA cm-2 at voltages of 1.631 and 1.753 V, respectively. Furthermore, the electrolytic cell also exhibits remarkable durability for at least 100 h at 200 mA cm-2 with negligible degradation in activity. The present work affords a deep insight into the influence of support on the activity of electrocatalyst and the strategy proposed in this research can also be extended to fabricate various other types of electrocatalysts for diverse electrocatalytic applications.
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Abundance of dominant-flocculated-species is the key to determine coagulation performance of coagulant. Titanium-based coagulants have garnered considerable attention due to their high coagulation efficiency, but with a current challenge of the identification and isolation of the dominant-flocculated-species. Herein, polytitanium chloride (PTC), enriched with dominant-flocculated-species, was successfully synthesized by electrodialysis through accurate micro-interface control of the reaction among Ti-hydrolyzed-species and OH-. Special attention was paid to a feasible and high-effective strategy to isolate the dominant-flocculated-species from PTC through one-step rapid ultrafiltration. Selective preference was the ultrafiltration membranes (made of polyethersulfone) with a molecular weight cut-off of 5 kDa, which enabled the isolation of the dominant-flocculated-species, named PTC-5k. Results from the electrospray time-of-flight mass spectrometry (ESI-TOF-MS) proved a large proportion of the small and medium-sized hydrolyzed products as dominant-flocculated-species in PTC-5k, with the main signals concentrated between m/z 100 and 500. This composition achieved approximately 15.0% higher removal of organic matter with a 33.0% reduction in dosage compared to PTC. Unique snowflake-like branched structure of PTC-5k enhanced the coagulation mechanisms of sweeping and adsorption-bridging flocculation. Worth noting was the more compact flocs formed by PTC-5k than PTC, which was the probable reason for the mitigated fouling of ceramic membrane when PTC-5k was utilized as pre-treatment methodology. Continuous operation of ceramic membrane filtration up to 30 h, demonstrated 30% improvement in stable flux compared to PTC. This study provides the strategy for the isolation of Ti-dominant-flocculated-species, and lays the foundation for practical application.
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Investigation of the reactivity of heteronuclear metal oxide clusters is an important way to uncover the molecular-level mechanisms of the doping effect. Herein, we performed a comparative study on the reactions of CH4 with NiAl3O6+ and Al4O6+ cluster cations at room temperature to understand the role of Ni during the activation and transformation of methane. Mass spectrometric experiments identify that both NiAl3O6+ and Al4O6+ could bring about hydrogen atom abstraction reaction to generate CH3⢠radical; however, only NiAl3O6+ has the potential to stabilize [CH3] moiety and then transform [CH3] to CH2O. Density functional theory calculations demonstrate that the terminal oxygen radicals (Ot-â¢) bound to Al act as the reactive sites for the two clusters to activate the first C-H bond. Although the Ni atom cannot directly participate in methane activation, it can manipulate the electronic environment of the surrounding bridging oxygen atoms (Ob) and enable such Ob to function as an electron reservoir to help Ot-⢠oxidize CH4 to [H-O-CH3]. The facile reduction of Ni3+ to Ni+ also facilitates the subsequent step of activating the second C-H bond by the bridging "lattice oxygen" (Ob2-), finally enabling the oxidation of methane into formaldehyde. The important role of the dopant Ni played in improving the product selectivity of CH2O for methane conversion discovered in this study allows us to have a possible molecule-level understanding of the excellent performance of the catalysts doping with nickel.
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Ba3Lu(BO3)3(BLB):Ce3+,Tb3+/Mn2+ phosphors were designed to explore effective and multifunctional applications. Under the excitation of near-ultraviolet (n-UV) light, the BLB:Ce3+ phosphor showed broad-band blue emission. After codoping with Mn2+ ions, the single-phase white light phosphor is achieved through the energy transfer (ET) between Ce3+ and Mn2+. In addition, thermal stability is significantly enhanced by the addition of Tb3+ (BLB:0.02Ce3+,0.20Tb3+) compared to that codoped with Mn2+ (BLB:0.02Ce3+,0.10Mn2+). The light-emitting diode (LED) device with warm white light emission is fabricated with UV-chip-coated BLB:0.02Ce3+,0.05Tb3+ and Sr2Si5N8:Eu2+ phosphors, showing a good potential application value for LEDs. Additionally, the spectral properties of borate-based phosphors (BLB:0.02Ce3+) under high pressure were studied for the first time. Surprisingly, the change of pressure enabled the emission peak of BLB:0.02Ce3+ to be tuned from 485 to 552 nm, and dλ/dP is 3.51 nm GPa-1. The color changes from blue to yellow with an increase of pressure. Compared with the reported data, the pressure-sensing sensitivity based on the central peak shift in this work is the highest in all Ce3+ single-doped samples. In addition, the emitting color and intensity were gradually regained after decompression. The intensity can reach 80% of the initial intensity. All data demonstrate that the BLB:0.02Ce3+ phosphor has the potential to be utilized as an optical pressure sensor due to the high-pressure sensitivity and visible color tuning.
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Optical pressure sensing by phosphors is a growing area of research. However, the main pressure measurement methods rely on the movement of the central peak position, which has significant drawbacks for practical applications. This paper demonstrates the feasibility of using the fluorescence intensity ratio (FIR) of different emission peaks for pressure sensing. The FIR (IBi3+/ILn3+) values of the synthesized YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors are all first-order exponentially related to pressure, and YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors have high pressure-sensing sensitivities (Sp and Spr), which are 6 times higher than those from our previously reported work. In addition, the changes in FIR values during the decompression process were also calculated, and the trend was similar to that during the compression process. The YNbO4:Bi3+,Eu3+ phosphor has better pressure recovery performance. In summary, the YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors reported in this paper are expected to be applied in the field of optical pressure sensing, and this study provides a new approach and perspective for designing new phosphors for pressure measurement.