Search

DNA self-assembled nanostructures have been considered as effective vehicles for biomolecule delivery because of their excellent biocompatibility, cellular permeability, noncytotoxicity, and small size. Here, we report an efficient antiviral strategy with self-assembled tetrahedral framework nucleic acids (tFNAs) delivering small interfering RNA (t-siRNA) to silence classical swine fever virus (CSFV) gene in porcine host cells. In this study, two previously reported siRNAs, C3 and C6, specifically targeting the CSFV genome were selected and modified on tFNAs, respectively, and termed t-C3 and t-C6. Results indicate that t-C3 and t-C6 can inhibit the viral proliferation of CSFV in kidney derived porcine cells, PK-15, effectively and that inhibition was markedly stronger than free siRNA-C3 or siRNA-C6 only. In addition, the DNA nanostructure also has high cargo-carrying capacity, allowing to deliver multiple functional groups. To improve the antiviral ability of tFNAs, a dual-targeting DNA nanostructure t-C3-C6 was constructed and used to silence the CSFV gene in porcine host cells. This study found that t-C3-C6 can inhibit the viral release and replication, exhibiting outstanding anti-CSFV capabilities. Therefore, these dual-targeting tFNAs have great potential in virus therapy. This strategy not only provides a novel method to inhibit CSFV replication in porcine cells but also verifies that tFNAs are effective tools for delivery of antiviral elements, which have great application potential.

MWW derivatives zeolite of MCM-22 with 3D layer structure, MCM-56 with partial disordered layer, MCM-36 with pillared layer and ITQ-2 with delaminated layer were prepared by hydrothermal synthesis and further modification to investigate the effect of acidic and interlayer structure on the catalytic performance of ethane dehydroaromatization and ethylene aromatization. With the retention of the MWW structure and confirmation of the intercalation or delamination efficiency, it was found that the increased exposed half-cup pocket and aluminum site on the external MWW layer structure can improve the xylene selectivity and catalytic stability. Although the amounts of total and strong acid site of H-form ITQ-2, MCM-36, MCM-56 are lower than those of MCM-22, the ratio of Lewis(L)/Bronsted(B) acid sites increases, which indicates that the exposed tri-coordinated framework aluminum in the half-cup pocket of external surface generated by exfoliation and pillaring can acted as the L acid sites. After loading Zn species, the strong acid amount and L acid sites amount are improved by the interaction between the loaded Zn species and MWW framework aluminum. The impregnated Zn species exist on the MWW zeolite with the state of ZnO and ZnAl2O4. The Zn species play roles of both ethane dehydrogenation and ethylene aromatization. The strong B acid sites play an important role for the oligomerization and aromatization of light olefins, while the excess amount of strong acid sites causes the increasing of cracking step which favors for light olefins production.

Solution-based processing of photovoltaic materials has important advantages, including lower overall costs and easier upscaling of fabrication, where the solvents play an essential role. Antisolvent crystallization technique is often applied to achieve high-quality perovskite materials. However, the basic chemistry of the solvent-antisolvent crystallization is still not well understood. Besides, common antisolvents are toxic, and their number is limited. In this work, a novel robot-based method was used to screen the efficient antisolvents for different solvent-perovskite systems. 336 combinations of perovskite-solvent-antisolvent could be prepared and characterized by the integrated robotic platform in 2 days. In addition, we provided a detailed working mechanism of the solvent-antisolvent crystallization approach. Furthermore, hundreds of potential antisolvents were proposed based on high-throughput screening and simulation. Verification tests match well with theory, and all reported antisolvents used for photovoltaic device optimizations are within our predicted range of the Hansen space, indicating that the predictions are reliable. In terms of solution-processed lead halide perovskite optoelectrical materials, suitable antisolvent is essential for the crystallization and properties of final products. Conventional experiments of antisolvent selections are based on the manual time-consuming trial-error methods, which cannot meet today's increasing demands. In this work, a robot-based method was used to screen the antisolvents for different solvent-perovskite systems in a high-throughput manner to study the influence of interactions among the solvent molecules, cations, metal-halides, and antisolvents, to build an informative database, and to reveal the working mechanism and selection criteria of antisolvents. Besides, simulations based on the screening results provide hundreds of potential antisolvents. Corresponding verification tests evidenced that our predictions are reliable and vital for designing future efficient mixed solvent systems for the fabrication of perovskite optoelectrical materials. A robotic platform is adopted to conduct a comprehensive solvent engineering for making lead halide perovskites in a high-throughput manner. Deeper insights into the working mechanisms and selection criteria of antisolvents are investigated and summarized. In addition, a reliable antisolvent database is established, and verification tests match well with the theory. Furthermore, our work provides significant guidance for designing functional and environment-friendly mixed solvent systems to fabricate high-quality perovskite materials or devices.

The facet-dependent electrical conductivity properties of silicon wafers result from significant band structure differences and variations in bond length, bond geometry, and frontier orbital electron distribution between the metal-like and semiconducting planes of silicon. To further understand the emergence of conductivity facet effects, electrochemical impedance measurements were conducted on intrinsic Si {100}, {110}, and {111} wafers. The attempt-to-escape frequency, obtained from temperature-dependent capacitance versus applied frequency curves, and other parameters derived from typical semiconductor property measurements were used to construct a diagram of the trap energy level (Et) and the amount of trap states Nt(Et). The trap states are located 0.61-0.72 eV above the silicon conduction band. Compared to {100} and {110} wafers, Si {111} wafer shows far less densities of trap states over the range of -0.2 to 2 V. Since these trap states inhibit direct electron excitation to the conduction band, the {111} wafer having much fewer trap states presents the best electrical conductivity property. Impedance data also provide facet-specific carrier lifetimes. The {111} surface gives consistently the lowest carrier lifetime, which reflects its high electrical conductivity. Lastly, ultraviolet photoelectron spectra and diffuse reflectance spectra were taken to obtain Schottky barriers between Ag and contacting Si wafers. The most conductive {111} surface presenting the largest Schottky barrier means the degrees of surface band bending used to explain facet-dependent electrical behaviors cannot be reliably attained this way.

Cesium lead iodide (CsPbI3) has attracted increasing attention for its photovoltaic applications, owing to its thermal stability and suitable band gap for tandem solar cells. However, the severe nonradiative recombination losses in CsPbI3-based perovskite solar cells generally restrict their open-circuit voltage (VOC) to the range of 0.9 to 1.1 V. This work uniquely reports a method to visualize all defect-assisted recombination pathways with photoluminescence (PL) techniques. Visible and valuable insight into the reduction of defect densities on a micrometer scale was obtained by the bottom surface and bulk passivation with barium hydroxide and trioctylphosphine oxide. The dual effects successfully improve the VOC of the solar cell from 0.87 to 1.17 V. These results highlight the potential of hyperspectral PL imaging as a powerful tool to give guidance to further suppress the nonradiative VOC losses in all-inorganic perovskites.

Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant pathogen that poses a significant risk to global health today. In S. aureus, α-hemolysin is an important virulence factor as it contributes to the capacity of the bacteria to infect the host. Here, we showed that biochanin A (bioA), an isoflavone present in red clover, cabbage and alfalfa, effectively inhibited hemolytic activity at a dose as low as 32 μg/mL. Further, western blot and RT-qPCR data showed that bioA reduced the production and expression of MRSA hemolysin in a dose-dependent manner. In addition, when different concentrations of bioA were added to a coculture system of A549 cells and S. aureus, it could significantly decrease cell injury. Importantly, the in vivo study showed that bioA could protect mice from pneumonia caused by a lethal dose of MRSA, as evidenced by improving their survival and reducing the number of bacterial colonies in lung tissues, the secretion of hemolysin into alveolar lavage fluid and the degree of pulmonary edema. In conclusion, biochanin A protected the host from MRSA infection by inhibiting the expression of the hemolysin of MRSA, which may provide experimental evidence for its development to a potential anti-MRSA drug.

Funding Information: The financial support from National Natural Science Foundation of China under contract number 22075205 and the support of Tianjin Municipal Science and Technology Commission under contract number 19JCYBJC21700 are gratefully acknowledged. The work has been also supported by the Program of Introducing Talents to the University Disciplines under file number B06006 , and the Program for Changjiang Scholars and Innovative Research Teams in Universities under file number IRT 0641 . Publisher Copyright: © 2021 Elsevier B.V. Cu–Ce0.8La0.1Sm0.1O2-δ and Cu–Ce0.8Nd0.1Sm0.1O2-δ are studied as anode materials for solid oxide fuel cells with methanol as fuel. The oxygen surface exchange and bulk diffusion coefficients of Ce0.8Sm0.2O2-δ both increase with La and Nd doping. The CH3OH temperature-programmed surface reaction results show that the addition of La and Nd accelerates the chemical oxidation of CH3OH. Furthermore, compared with Cu–Ce0.8Sm0.2O2-δ, the anodes with La and Nd show higher resistance to coking in CH3OH atmosphere. The Cu-based cermet anode exhibits a low catalytic activity for the electrochemical oxidation of H2, and a single cell supported by a Ce0.8Sm0.2O2-δ‑carbonate composite electrolyte with Cu–Ce0.8Sm0.2O2-δ anode exhibits a maximum power density of 160 mW cm−2 at 650 °C using dry hydrogen as fuel. However, the maximum power density reaches 550 mW cm−2 when CH3OH is used as fuel, and further increases to 730 and 830 mW cm−2 with the addition of La and Nd in the anode, respectively. The results indicate that withthe promotion of the oxygen activity, the Cu-based cermet is a promising anode material for solid oxide fuel cells using CH3OH as fuel.

Staphylococcus aureus (S. aureus) is a common pathogenic bacterium that induces a variety of diseases in humans and animals. The significant pathogenicity of S. aureus is due to its expression of several virulence factors. Alpha-hemolysin (Hla) has attracted attention as a virulence factor in staphylococcal pathogenesis and has been the predominant focus of intense research. In this study, we found that kaempferol, a flavonoid compound, inhibited hemolysis at a low concentration (32 μg/mL) and exerted no effect on bacterial growth. Western blot and RT-qPCR assays further demonstrated that kaempferol downregulated the expression of Hla in S. aureus. We observed that kaempferol alleviated the damage from S. aureus Hla in A549 cells. More importantly, kaempferol showed a potent protective effect on mice pneumonia induced by MRSA, as evidenced by a significant improvement in the survival of mice, a reduction in the number of colonized colonies in lung tissue and a decrease in the pathological damage to lung tissues. In summary, the results demonstrate the protective effect of kaempferol on MRSA-induced lethal pneumonia in mice and indicate that kaempferol could be developed as a potential anti-MRSA drug.

Funding Information: The work was financially supported by the National Natural Science Foundation of China ( 21636007 ). Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Azobenzene (azoB) is a promising anode active material for nonaqueous redox flow battery (NARFB), but the battery performance assembled with azoB is rather poor. Here, we show that the rate performance of NARFB with azoB and 2,5-di-tert-butyl-1-methoxy-4-[2′-methoxyethoxy] benzene (DBMMB) as anolyte and catholyte active materials can be significantly enhanced by optimizing the solvent, supporting electrolyte, and membrane. The synergistic interaction among active materials, solvent (acetonitrile), supporting electrolyte (tetraethylammonium bis(trifluoromethylsulfonyl)imide), and membrane (Daramic 175) contributes to the high battery performance. It exhibits an energy efficiency of 63.5% even at an ultra-high current density of 100 mA cm−2. Furthermore, the battery delivers a peak power density of 336 mW cm−2 at the current density of 240 mA cm−2 with 0.25 M active materials, which is a new benchmark for NARFBs.

Ni-MnOx-Ce0.8Sm0.2O1.9 (SDC) composites are synthesized and investigated as anode materials of solid oxide fuel cells fed with methanol. The lowest anodic polarization resistance is obtained when the molar ratio of Mn to Ni is 0.05:0.95. The high catalytic activity is attributed to the transfer of electrons from Ni to Mn and the increase of the content of the lattice oxygen in the anode. The single cell with that anode and SDC-carbonate composite electrolyte exhibits a maximum power density of 722 mW cm-2 at 700 °C. Mn also increases the resistance to carbon deposition of the anode due to the high lattice oxygen content and the redox cycle of the Mn species. The stability of the single cell is enhanced with the increase of the content of Mn in the anode.

Ni 1-x Zn x O-Ce 0.8 Sm 0.2 O 1.9 is studied as an anode material for solid oxide fuel cells with hydrogen and methanol as fuels. After reduction, Zn is incorporated into the lattice of Ni when x is less than 0.5, while NiZn alloy accompanied with ZnO is formed when x reaches 0.8. The electrochemical oxidation process of H 2 on the anode is investigated with a symmetric cell under various H 2 partial pressures. The addition of Zn increases the electron cloud density of Ni and thus weakens the adsorbing strength of H on Ni, accelerating the surface diffusion of H species, which is the rate determining step when the content of Zn is lower than 0.5. ZnO in the reduced Ni 0·2 Zn 0·8 O- Ce 0.8 Sm 0.2 O 1.9 anode facilitates H spillover, resulting in the variation of the rate determining step and the highest activity of the anode. The cell with Ni 0·2 Zn 0·8 O- Ce 0.8 Sm 0.2 O 1.9 anode shows the highest performance with both H 2 and methanol fuels at 700 °C. ZnO also improves coking resistance of NiO-Ce 0.8 Sm 0.2 O 1.9 anode.

A highly active anode material for solid oxide fuel cells resistant to carbon deposition is developed. Co-Fe co-doped La 0.5 Ba 0.5 MnO 3- with a cubic-hexagonal heterogeneous stucture is synthesized through the Pechini method. An A-site ordered double perovskite with Co 0.94 Fe 0.06 alloy-oxide core-shell nanoparticles on its surface is formed after reduction. The phase transition and the exsolution of the nanoparticles are investigated with X-ray diffraction, thermogravimetric analysis, and high-resolution transmission electron microscope. The exsolved nanoparticles with the layered double-perovskite supporter show a high catalytic activity. A single cell with that anode and a 300 μm thick La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 electrolyte layer exhibits maximum power densities of 1479 and 503 mW cm -2 at 850 °C with wet hydrogen and wet methane fuels, respectively. Moreover, the single cell fed with wet methane exhibits a stable power output at 850 °C for 200 h, demonstrating a high resistance to carbon deposition of the anode due to the strong anchor of the exsolved nanoparticles on the perovskite parent. The oxide shell also preserves the metal particles from coking.

Sr 2-x Na x FeMo 0.65 Ni 0.35 O 6-δ is synthesized as an anode material for solid oxide fuel cells. The effects of Na on the crystalline phase and electrical properties are investigated. The main perovskite phase changes into a Ruddlesden-Popper structure after reduction when x is less than 0.1, while the material with a higher amount of Na keeps the perovskite structure. FeNi x alloy nanoparticles are exsolved during reduction, in which the content of Ni increases with the rise of Na amount. The surface oxygen vacancy concentration is also influenced by the doping of Na, and the highest value is reached when x is 0.1. Sr 1.9 Na 0.1 FeMo 0.65 Ni 0.35 O 6-δ anode exhibits the highest activity, and a single cell supported by a 300-μm-thick La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ electrolyte layer shows maximum power densities of 1495 and 627 mW cm −2 at 850 °C with H 2 and wet CH 4 as fuels, respectively. The coking resistance of the anode is also improved with Na doping.

Pancreatic cancer is a common malignant tumor with a high incidence and mortality rate. The prognosis of patients with pancreatic cancer is considerably poor due to the lack of effective treatment in clinically. Despite numerous studies have revealed that baicalein, a natural product, is responsible for suppressing multiple cancer cells proliferation, motility and invasion. The mechanism by which baicalein restraining pancreatic cancer progression remains unclear. In this study, we firstly verified that baicalein plays a critical role in inhibiting pancreatic tumorigenesis in vitro and in vivo. Then we analyzed the alteration of microRNAs (miRNAs) expression levels in Panc-1 cells incubated with DMSO, 50 and 100 μM baicalein by High-Throughput sequencing. Intriguingly, we observed that 20 and 39 miRNAs were accordingly up- and down-regulated through comparing Panc-1 cells exposed to 100 μM baicalein with the control group. Quantitative PCR analysis confirmed that miR-139-3p was the most up-regulated miRNA after baicalein treatment, while miR-196b-5p was the most down-regulated miRNA. Further studies showed that miR-139-3p induced, miR-196b-5p inhibited the apoptosis of Panc-1 cells via targeting NOB1 and ING5 respectively. In conclusion, we demonstrated that baicalein is a potent inhibitor against pancreatic cancer by modulating the expression of miR-139-3p or miR-196b-5p.

La0.5Ba0.5Mn1-xCoxO3-δ (x < 0.4) with a perovskite structure is studied as a cathode material for solid oxide electrolysis cells. The exsolution of metallic Co from the perovskite in a reducing atmosphere is in situ investigated. Co improves the electrical conductivity of La0.5Ba0.5MnO3-δ in a reducing atmosphere, and facilitates the oxygen exchange reaction on the cathode surface. The cathode with in situ exsolved Co nanoparticles shows a high activity for both H2O and CO2 electrolysis. At 1.3 V, a single cell supported by a La0.8Sr0.2Ga0.8Mg0.2O3-δ electrolyte layer achieves H2O electrolysis current densities of 0.46 and 1.01 A cm-2 at 700 and 800 °C, respectively. A high CO2 electrolysis current density of 0.88 A cm−2 is also obtained with the same cell at 1.2 V and 850 °C with a Faradaic efficiency exceeding 90 %. The cathode exhibits a high stability for H2O and CO2 electrolysis. The co-electrolysis of H2O and CO2 with the cathode is also studied.

The surface properties of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) perovskite electrode are modified with HNO3 treatment to improve its catalytic activity towards oxygen reduction reaction between 500–650 °C. The surface concentrations of A-site cations are reduced after the acid etching. After the calcination at 1150 °C, severe segregation of Sr is observed on the surface of untreated LSCF powder, which is suppressed remarkably with the HNO3 pretreatment. Highly reactive oxygen species and Fe4+ species are formed on the surface of LSCF after the HNO3 treatment, which are beneficial to oxygen reduction reaction. The reduction of oxygen species adsorbed on the LSCF surface, the rate-determining step of the electrode process, is accelerated significantly with the acid etching.

An improved SOFC anode with excellent stability against carbon deposition with syngas as fuel is reported. The anode material is Ni–La0.8Sr0.2FeO3 (LSF) composite synthesized by anhydrous impregnation. After reduction in wet H2 (3% H2O), the material partially decomposes to SrLaFeO4 and exsolved Fe. The exsolved Fe forms Ni–Fe alloy with impregnated Ni. The particle size of Ni–Fe alloy is about 20–50 nm. The Ni–Fe alloy nanoparticles disperse on the surface of the La0.8Sr0.2FeO3 and SrLaFeO4 oxides. The increase of Ni content promotes the exsolution of Fe and increases the reaction sites of Ni–Fe alloy. With the increase of the Ni content, the electrical conductivity and catalytic activity are enhanced, which improves the electrochemical performance of the single cell. The cell with 10 mol.% Ni impregnated Ni-LSF as anode achieves a maximum power density of 550 mW cm−2 at 700 °C fueled with syngas. The strong interaction of the nano-sized Ni–Fe alloy with the LaxSryFeOz (La0.8Sr0.2FeO3 or SrLaFeO4) oxide substrate efficiently suppresses carbon deposition with high graphitization degree. Besides, the SrLaFeO4 phase which can accommodate interstitial oxygen facilitates the removal of the deposited carbon.

Alloying structurally similar perovskites to form mixed-cation lead iodide perovskites, e.g., ${\mathrm{Cs}}_{x}\mathrm{F}{\mathrm{A}}_{(1\ensuremath{-}x)}\mathrm{Pb}{\mathrm{I}}_{3}, \mathrm{M}{\mathrm{A}}_{x}\mathrm{F}{\mathrm{A}}_{(1\ensuremath{-}x)}\mathrm{Pb}{\mathrm{I}}_{3}$, and ${\mathrm{Cs}}_{x}\mathrm{M}{\mathrm{A}}_{y}\mathrm{F}{\mathrm{A}}_{(1\ensuremath{-}x\ensuremath{-}y)}\mathrm{Pb}{\mathrm{I}}_{3}$, could improve the performance of perovskite-based solar cells and light-emitting diodes. However, a phase diagram of them and a clear understanding of the underlying atomic-scale mechanism are still lacking. Using ab initio calculations combined with high-throughput experimentation, we demonstrate the phase diagram of mixed-cation lead iodide perovskites. Only a small proportion of monovalent cations (${\mathrm{Cs}}^{+}/{\mathrm{Rb}}^{+}/{\mathrm{MA}}^{+}$) could be incorporated into the ${\mathrm{FAPbI}}_{3}/{\mathrm{MAPbI}}_{3}$ matrix; otherwise it will be separated into \ensuremath{\delta}-${\mathrm{CsPbI}}_{3}$, \ensuremath{\delta}-${\mathrm{RbPbI}}_{3}$, MAI, etc. The smaller the radius of doping cations, the harder it is to incorporate them into a perovskite lattice and the easier it is to stabilize the perovskite phase. In ${\mathrm{FAPbI}}_{3}$-based multication perovskites, moreover, over 10 mol % alloying is needed to convert \ensuremath{\delta} phase to \ensuremath{\alpha} phase at room temperature. The combined upper and lower limits for doping concentration restrict the appropriate alloying ratio to a narrow window. We further plot the relative energy diagram for triple-cation perovskite ${\mathrm{Cs}}_{x}\mathrm{M}{\mathrm{A}}_{y}\mathrm{F}{\mathrm{A}}_{(1\ensuremath{-}x\ensuremath{-}y)}\mathrm{Pb}{\mathrm{I}}_{3}$, which reveals the ideal doping ratio for uniform stable alloying. This theory-experiment-combined study provides a clear microscopic picture of phase stability and segregation for mixed-cation perovskite solids.

Ni/Ce0.8Sm0.2O1.9 (SDC) with a three-dimensionally ordered macroporous (3DOM) structure is prepared with poly(methyl methacrylate) as the template and characterized using X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, H2 temperature-programmed reduction, X-ray photoelectron spectroscopy and ultraviolet Raman spectroscopy. Lattice oxygen in 3DOM SDC shows a higher activity than that in hydrothermally synthesized bulk SDC. 3DOM SDC also exhibits a stronger interaction with Ni compared to bulk SDC, which facilitates the release of lattice oxygen and the formation of oxygen vacancies in SDC in a reducing atmosphere. Therefore, Ni/3DOM SDC shows a much higher catalytic activity for electrochemical oxidation than Ni/bulk SDC as the anode material of solid oxide fuel cells. With Ni/3DOM SDC as the anode, a cell supported by a 500 μm-thick SDC-carbonate composite electrolyte layer exhibits maximum power densities (Pmax) of 1.28 and 1.63 W cm-2 at 700 °C with H2 and methanol as fuels, respectively, more than twice the Pmax of a similar cell with a Ni/bulk SDC anode. The Ni/3DOM SDC anode also shows a high resistance to coking.

The organic-inorganic halide perovskites (OIHPs) have shown enormous potential for solar cells, while problems like the current-voltage hysteresis and the long-term instability have seriously hindered their applications. Ion migrations are believed to be relevant. But the atomistic details still remain unclear. Here we study the migrations of ions in CH3NH3PbI3 (MAPbI3) at varying temperatures ( T's), using combined experimental and first-principle theoretical methods. Classical hopping of the iodide ions is the main migration mechanism at moderate T's. Below ∼270 K, the kinetic constant for ionic migration still shows an Arrenhius dependency, but the much lower activation energy is attributed to the migration of H+. A gradual classical-to-quantum transition takes place between ∼140 and ∼80 K. Below ∼80 K, the kinetic constant becomes T-independent, suggesting that deep quantum tunneling of H+ takes over. This study gives direct experimental evidence for the migrations of H+s in MAPbI3 and confirms their quantum nature.

Photocarrier generation in a material, transportation to the material surface, and collection at the electrode interface are of paramount importance in any optoelectronic and photovoltaic device. In the last collection process, ideal performance comprises ultrafast charge collection to enhance current conversion efficiency and broadband collection to enhance energy conversion efficiency. Here, for the first time, we demonstrate ultrafast broadband charge collection achieved simultaneously at the clean graphene/organic–inorganic halide perovskite interface. The clean interface is realized by directly growing perovskite on graphene surface without polymer contamination. The tunable two-color pump–probe spectroscopy, time-resolved photoluminescence spectroscopy, and time-dependent density functional theory all reveal that the clean-interfacial graphene collects band-edge photocarriers of perovskite in an ultrashort time of ∼100 fs, with a current collection efficiency close to 99%. In addition, graphene can ...

The degradation of perovskite solar cells in the presence of trace water and oxygen poses a challenge for their commercial impact given the appreciable permeability of cost-effective encapsulants. Point defects were recently shown to be a major source of decomposition due to their high affinity for water and oxygen molecules. Here, we report that, in single-cation/halide perovskites, local lattice strain facilitates the formation of vacancies and that cation/halide mixing suppresses their formation via strain relaxation. We then show that judiciously selected dopants can maximize the formation energy of defects responsible for degradation. Cd-containing cells show an order of magnitude enhanced unencapsulated stability compared to state-of-art mixed perovskite solar cells, for both shelf storage and maximum power point operation in ambient air at a relative humidity of 50%. We conclude by testing the generalizability of the defect engineering concept, demonstrating both vacancy-formation suppressors (such as Zn) and promoters (such as Hg). Despite their high efficiencies, perovskite solar cells still suffer from degradation issues that impede their practical deployment. Saidaminov et al. explore the effect of local lattice strain on vacancy formation and show that careful choice of dopants plays a key role, enhancing the device stability.

Activated carbons (AC) pretreated with HNO3 and NaOH are investigated as the fuel of direct carbon fuel cells. HNO3 and NaOH treatments both increase the oxygen content and decrease the graphitization degree of AC. The amount of hydroxyl groups on the surface of AC increases after the treatments with HNO3 and NaOH, and then decreases during the subsequent heating process in an inert atmosphere. On the contrary, the carbonyl and quinone groups on the surface of the activated carbon remain stable during the heating process. The activated carbon treated with HNO3 shows the highest reactivity towards oxidation and reverse Boudouard reactions due to its lowest graphitization degree and highest oxygen content. The single cell with a 380 μm-thick yttria stabilized zirconia layer as the electrolyte and the activated carbon treated with HNO3 as the fuel exhibits the lowest polarization and the highest maximum power density of 128 mW cm−2 at 800 °C.

Ce0.8Sm0.2O1.9 (SDC) powder is impregnated with LaNi0.9Co0.1O3 (LNC) to form a composite anode for solid oxide fuel cells with methanol as fuel. Nanoparticles of Ni-Co alloy are derived from LNC after reduction. The composite anode shows a sufficient electrical conductivity when the weight ratio of Ni to SDC reaches 0.1, which is much lower than the amount of Ni required in conventional Ni-SDC anodes. The aggregation of Ni-Co nanoparticles in the reduced anode is suppressed by the oxide supporter, resulting in an improved catalytic activity. The single cell with LNC-SDC composite anode and SDC-carbonate composite electrolyte exhibits a maximum power density of 872 mW cm−2 at 700 °C with gasified methanol as the fuel, much higher than that of the cell with a NiCo-SDC anode under the same condition. The amount of carbon deposited on the anode in methanol atmosphere decreases with the decline of the LNC content. The cells with LNC-SDC composite anodes exhibit stable performances during a 500-minute discharge period.

NbOx is added in Ni-Ce0.8Sm0.2O1.9 by impregnation as an anode material for solid oxide fuel cells fed with methanol. Nb (IV) and Nb (V) exist in the reduced anode. The addition of Nb reduces the binding energy of Ni. The catalytic activity of the anode and the performance of the single cell both increase with the increase of Nb. At 700 °C, the cell with 5NbOx-Ni-Ce0.8Sm0.2O1.9 anode and Ce0.8Sm0.2O1.9-carbonate electrolyte shows a output power density of 687 mW cm−2. Meanwhile, water produced in the anode is absorbed by NbOx and forms surface hydroxyl groups, which facilitates the removal of carbon. The addition of NbOx decreases the amount of deposited carbon in the humidified methanol atmosphere significantly, and an improved stability of the single cell is achieved.

Simultaneously enhancing device performance and longevity, as well as balancing the requirements on cost, scalability, and simplification of processing, is the goal of interface engineering of organic solar cells (OSCs). In our work, we strategically introduce antimony (Sb3+) cations into an efficient and generic n-type SnO2 nanoparticles (NPs) host during the scalable flame spray pyrolysis synthesis. Accordingly, a significant switch of conduction property from an n-type character to a p-type character is observed, with a corresponding shift in the work function (WF) from 4.01 ± 0.02 eV for pristine SnO2 NPs to 5.28 ± 0.02 eV for SnO2 NPs with 20 mol. % Sb content (ATO). Both pristine SnO2 and ATO NPs with fine-tuned optoelectronic properties exhibit remarkable charge carrier extraction properties, excellent UV resistance and photo-stability being compatible with various state-of-the-art OSCs systems. The reliable and scalable pristine SnO2 and ATO NPs processed by doctor-blading in air demand no complex post-treatment. Our work offers a simple but unique approach to accelerate the development of advanced interfacial materials, which could circumvent the major existing interfacial problems in solution-processed OSCs.

Ni 1-x Co x O-Ce 0.8 Sm 0.2 O 1.9 (SDC) composite is investigated as an anode material for solid oxide fuel cells with methanol as fuel. The interaction between NiO and SDC phases is enhanced by Co. Besides, Co reduces the particle size and improves the dispersion of Ni 1-x Co x O by inhibiting the grain growth of NiO, which results in larger three-phase boundary in the anode layer. The Ni 0.9 Co 0.1 -SDC anode shows the lowest polarization resistance. A maximum power density of 675 mW cm −2 is achieved by a single cell with Ni 0.9 Co 0.1 -SDC anode and SDC-carbonate composite electrolyte at 700 °C. Co also increases the resistance to carbon deposition of the anode and decreases the graphitization degree of deposited carbon with methanol as fuel. The cell with the Ni 0.9 Co 0.1 -SDC anode exhibits a stable performance during a 500-min discharge period.

Sm0.5Ba0.5MnO3-δ (SBMO) has been synthesized with the Pechini method and investigated as an anode material of solid oxide fuel cells with H2 and methanol as fuels. A cubic perovskite structure is formed after reduction. The reduction process of SBMO is studied with X-ray photoelectron spectroscopy and temperature programmed reduction techniques. The electrical conductivities of an SBMO sample sintered at 950 °C are 1.15 and 0.10 S cm−1 at 850 °C in air and H2, respectively. A single cell with an SBMO anode layer and a 300-μm La0.8Sr0.2Ga0.8Mg0.2O3-δ electrolyte layer exhibits a maximum power density (Pmax) of about 150 mW cm−2 at 850 °C with H2 as fuel. The electrical conductivity of the anode layer with methanol as fuel is improved by the moderate carbon deposition, and the Pmax increases to about 415 mW cm−2. The cell fed with methanol also shows a promising stability.

Herpesviruses, known as large DNA viruses, have a wide host range. In addition to human beings, cattle, and horses, even carp can be hosts for herpesvirus infection. Herpesviruses are pathogens possessing elaborate mechanisms that regulate host cell components for its replication, assembly and generating mature virus particles that can infect humans and most animals, usually causing multiple and lifelong infections. In addition, several human diseases, such as genital or mouth herpes, mononucleosis, and Burkitt lymphoma, are usually associated with herpesvirus infection. Blocking the steps of viral infection, such as entry, replication and assembly, may be an effective way for many different herpes viruses and their related diseases. Therefore, we aim to describe antiviral agents that are able to prevent herpesvirus entry, replication and assembly in host cells. We summarize antiviral strategies, including certain small molecular drugs, RNA interference and CRISPR/Cas9 system-based antiviral approaches, which represent promising approaches.

Funding Information: The financial support from National Natural Science Foundation of China under contract number 22075205 and the support of Tianjin Municipal Science and Technology Commission under contract number 19JCYBJC21700 are gratefully acknowledged. The work has been also supported by the Program of Introducing Talents to the University Disciplines under file number B06006, and the Program for Changjiang Scholars and Innovative Research Teams in Universities under file number IRT 0641. Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. BaCe0.2Fe0.8-xPrxO3-δ (x = 0–0.3) is studied as a cobalt-free cathode material for proton-conducting solid oxide fuel cells. The cathode is composed of a cubic BaFeO3-δ phase and an orthorhombic BaCeO3-δ phase, and Pr is doped in both phases. The partial substitution of Pr for Fe decreases the content of the BaFeO3-δ phase, leading to a lower electrical conductivity. BaCe0.2Fe0.6Pr0.2O3-δ has the most adsorbed oxygen and Fe3+ on the surface, resulting in the fastest oxygen surface exchange kinetics and the highest activity. The partial pressure of H2O shows a negligible effect on the polarization resistance of the cathode. In contrast, the polarization resistance increases remarkably with the decrease of oxygen partial pressure, indicating that the rate of the cathode process is controlled by the surface exchange of oxygen. At 700 °C, BaCe0.2Fe0.6Pr0.2O3-δ shows the lowest polarization resistance of 0.057 Ω cm2, and a single cell with that cathode exhibits the highest maximum power density of 562 mW cm−2. Theresults demonstrate that Pr doped BaCe0.2Fe0.8O3-δ is a promising cobalt-free cathode material for proton-conducting solid oxide fuel cells.

CO2 perm-selective ceramic/carbonate dual phase membranes are promising in a number of high temperature separation and reaction processes for CO2 capture or process intensification. The stability of these membranes in gas containing SO2 is important for their applications dealing with sulfur containing stream. The present work studies gas permeation performance and stability of Ce0.8Sm0.2O1.9 (SDC)/Li2CO3-Na2CO3 membrane in SO2 containing gas. During CO2 permeation through the SDC/carbonate membrane with feed gas containing SO2, the CO2 permeation flux decreases with on-stream time and the decrease rate increases with the SO2 concentration in the feed gas. The SDC phase remains unchanged after exposure to SO2 containing gas, but the SO2 exposure of the SDC-carbonate dual phase membrane results in formation of sulfate in the carbonate phase in the membrane. The sulfate content in the molten salt phase increases with SO2 concentration in the gas or exposure time. CO2 permeation flux through SDC/carbonate-sulfate dual phase membranes prepared in this work decreases with the increase of the sulfate content in the molten salt phase. The formation of sulfate in the carbonate phase lowers carbonate ion conductivity which becomes the dominant step causing a reduction in CO2 permeance.

NiO-Ce 0.8 Sm 0.2 O 1.9 (Ni-SDC) composite anode powders are synthesized with a hydrothermal technique. The average size of the particles in the anode powder is about 10 nm. Different phases distribute uniformly in the composite. The anode sintered at 700 °C exhibits an electrical conductivity of above 100 S cm −1 , three orders of magnitude higher than that of a similar solid-mixed composite anode with the same composition. The anode synthesized through the hydrothermal process also possesses a higher catalytic activity. An SDC-carbonate composite electrolyte-supported single cell with the composite anode exhibits a maximum power density of 738 mW cm −2 at 700 °C with H 2 as fuel, much higher than that of a similar cell with a solid-mixed anode. The cell also exhibits a promising stability with methanol as fuel.

In this work, a solid oxide fuel cell with 60 μm samarium doped ceria film as the electrolyte is fabricated with a co-pressing technique. The performance of the cell is measured at 600, 650 and 700 °C. The corresponding maximum power outputs are 236, 331 and 401 mW cm −2 , respectively. The measured current–voltage ( I – V ) curves are straight lines. A linear discharge model is derived based on the Gorelov and Liu modified electromotive force (EMF) equations. The model fits the measured I – V curves with the maximum errors less than 1.5%. The overall activation overpotential of the cell is therefore postulated to be proportional to the polarization current.

Samarium doped ceria (SDC) shows obvious electronic conduction in a reducing atmosphere, which results in internal short-circuiting of the SOFC. In this work, we initiatively combine the Gorelov modified electromotive force (EMF) method and the Liu modified EMF method to determine the internal electronic resistance of the SOFC with 60 μm SDC film electrolyte. The internal electronic resistance determined with the Gorelov modified EMF method is a little larger than that determined with the Liu modified EMF method. The power loss of the SOFC is mainly resulted from the internal short-circuiting, oxygen ionic resistance and electrode polarization resistance. At low external current density, the internal short-circuiting power loss is predominant, while at high current density the oxygen ionic resistance power loss is predominant. Temperature has little effect on the maximum efficiency of the SOFC. When the SOFC works at the maximum power output, the efficiency of the cell is about 30%, but if the electronic conduction of the SDC electrolyte could be eliminated, the efficiency could be improved by 2.5 times.

A new electroactive species benzophenone (BP) is identified for the anolyte of an all-organic redox flow battery (AORFB) due to its low redox potential, high electrochemical reversibility and stability, and high solubility in non-aqueous electrolyte. BP also shows high stability in a wide temperature range, and the elevated temperature enhances the redox reactions and the mass transfer rates, leading to an exponential increase of the diffusion coefficient. An AORFB based on BP anolyte is achieved with a cell voltage of 2.41 V and a theoretical energy density of 139 Wh L−1. The cycling performance shows a stable coulombic efficiency of 81%. The results presented indicate that organic molecule BP is a promising anolyte active species for high-energy density AORFBs.

Preparing small, highly dispersed Ni2P particles is important for improving the hydrogenation ability of Ni2P. Here, Ni2P nanoparticles (approximately 4.3 nm) on mesoporous zeolite ZSM-5 (Ni2P/MZSM-5-CA) were prepared using citric acid (CA) as an assistant agent. The formation mechanism of small Ni2P particles when CA was added was investigated by combining UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and temperature-programmed reduction with a transmission electron microscope and CO chemisorption. The results indicated that the formed CA–Ni complex with high viscosity favors the Ni precursor dispersed on the dried catalyst. After calcination, the released Ni species strongly interacted with surface acidic hydroxyl groups on MZSM-5, leading to the formation of Ni2P particles with small sizes and good dispersion under a reducing atmosphere. The reaction rate constants and TOFs over Ni2P/MZSM-5-CA (16.2 × 10−2 μmol g−1 s−1 and 9.7 × 10−4 s−1) are much higher than over Ni2P/MZSM-5 (8.2 × 10−2 μmol g−1 s−1 and 8.3 × 10−4 s−1) in 4,6-dimethyldibenzothiophene hydrodesulfurization. In addition, Ni2P/MZSM-5-CA catalyst shows higher activity than Ni2P catalyst without CA in phenanthrene hydrogenation.

La2O3 and Sm2O3 are added into Ni-Mo-Ce0.8Sm0.2O1.9 (SDC) as anodes of solid oxide fuel cells with methanol as fuel. The rare earth oxides improve the catalytic oxidation of the fuel, resulting in the decrease of anodic polarization resistance. The single cell with La2O3-Ni-Mo-SDC as the anode and SDC-carbonate composite as the electrolyte exhibits a maximum power density of 765 mW cm−2 at 700°C. The oxides in the anodes also improve the stability of single cells due to the accelerated oxidation of the deposited carbon and the suppression of the deposition of carbon with a high graphitization degree.

Objectives Clinical observations have demonstrated that copper levels elevate in several cancer types, and copper deprivation is shown to inhibit tumour angiogenesis and growth in both animal models and preclinical trials. However, the content of copper in pancreatic duct adenocarcinoma (PDAC) and whether it is a potential therapy target is still unknown. Materials and Methods The levels of copper in PDAC specimens were detected by ICP‐MS assays. Copper depletion in Panc‐1 or MiaPaCa‐2 cells was conducted via copper transporter 1 (SLC31A1) interference and copper chelator tetrathiomolybdate (TM) treatment. The effects of copper deprivation on cancer cells were evaluated by cell proliferation, migration, invasion, colony formation and cell apoptosis. The mechanism of copper deprivation‐caused cancer cell quiescence was resolved through mitochondrial dysfunction tests and autophagy studies. The tumour‐suppression experiments under the condition of copper block and/or autophagy inhibition were performed both in vitro and in xenografted mice. Results SLC31A1‐dependent copper levels are correlated with the malignant degree of pancreatic cancer. Blocking copper absorption could inhibit pancreatic cancer progression but did not increase cell death. We found that copper deprivation increased mitochondrial ROS level and decreased ATP level, which rendered cancer cells in a dormant state. Strikingly, copper deprivation caused an increase in autophagy to resist death of pancreatic cancer cells. Simultaneous treatment with TM and autophagy inhibitor CQ increased cell death of cancer cells in vitro and retarded cancer growth in vivo. Conclusions These findings reveal that copper deprivation‐caused cell dormancy and the increase in autophagy is a reason for the poor clinical outcome obtained from copper depletion therapies for cancers. Therefore, the combination of autophagy inhibition and copper depletion is potentially a novel strategy for the treatment of pancreatic cancer and other copper‐dependent malignant tumours.

Organic-inorganic hybrid perovskite solar cells (PSCs) have seen a rapid rise in power conversion efficiencies in recent years; however, they still suffer from interfacial recombination and charge extraction losses at interfaces between the perovskite absorber and the charge-transport layers. Here, in situ back-contact passivation (BCP) that reduces interfacial and extraction losses between the perovskite absorber and the hole transport layer (HTL) is reported. A thin layer of nondoped semiconducting polymer at the perovskite/HTL interface is introduced and it is shown that the use of the semiconductor polymer permits-in contrast with previously studied insulator-based passivants-the use of a relatively thick passivating layer. It is shown that a flat-band alignment between the perovskite and polymer passivation layers achieves a high photovoltage and fill factor: the resultant BCP enables a photovoltage of 1.15 V and a fill factor of 83% in 1.53 eV bandgap PSCs, leading to an efficiency of 21.6% in planar solar cells.

The crossover of anolyte and catholyte during cycling places a serious obstacle for the performance of non-aqueous redox flow batteries (NARFBs). Employing symmetric RFB is an effective strategy to alleviate this issue. A new bi-redox material, 1-(ferrocenylmethyl-amino)-anthraquinone (FcMeAAQ) composed of ferrocene and anthraquinone two moieties, is designed for symmetrical NARFB. Both experimental and density functional theory calculational results show the relatively good stability of FcMeAAQ when one-electron redox reaction is involved. The assembled symmetric NARFB with the Daramic AA-250 porous membrane delivers an open circuit voltage of 1.42 V, Coulombic efficiency of 90.8%, and energy efficiency of 81.8% over 100 cycles at the current density of 2 mA cm−2. Furthermore, a peak power density of ~16 mW cm−2 is achieved at the state of charge of 100%.

Ni-Mo-Ce 0.8 Sm 0.2 O 1.9 (SDC) composites are prepared and investigated as anodes of solid oxide fuel cells with methanol as fuel. The addition of Mo improves the catalytic activity for methanol pyrolysis and the resistance to carbon deposition of Ni-SDC anode. The anode with a mole ratio of Mo to Ni of 0.03:1 exhibits the lowest polarization resistance. The cell with that anode and SDC-carbonate composite electrolyte shows a maximum power density of 680 mW cm −2 at 700 °C. The stability of the cell is enhanced with the increase of the content of Mo in the anode, which is mainly attributed to the decreased amount of carbon deposits with a high graphitization degree.

Ion migration has been regarded as the major cause of photocurrent hysteresis. Here we use photoluminescence (PL) and optical images, combined with Galvanostatic measurement, to detect the ionic motion. We observe an irreversible PL and optical transmittance change after electric poling. By comparing a neat perovskite film with the sample coated by poly(methyl methacrylate) (PMMA), polyethylene glycol (PEG), and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), we found that PCBM effectively inhibits ionic motion near the surface of the perovskite.We further evidenced the donor–acceptor complex formed between PCBM and perovskite, implying the mechanism of inhibited ion migration by PCBM. We close by demonstrating that PCBM can also be introduced on the top of perovskite fim in an n–i–p TiO2 planar structure, to achieve an average 14% steady-state output over 2.3 × 105 s (∼64 h). This work highlights the importance of inhibiting ionic motion in perovskite solar cells.

Developing highly active hydrodesulfurization (HDS) catalysts is very important for ultraclean fuel production. Here, we report the successful preparation of crystalline mordenite nanosheet assemblies (NS-HMOR) with large external surface area and micro–mesoporous structure. After introduction of nickel and phosphorus species into NS-HMOR and its activation, the obtained Ni2P/NS-HMOR catalyst exhibits higher HDS activity (TOF = 1.9 × 10−3 s−1) and better stability in 4,6-dimethyldibenzothiophene HDS than a silica-supported Ni2P catalyst (TOF = 1.3 × 10−3 s−1). The large number of acidic hydroxyl groups on the NS-HMOR surface facilitates the formation of very small Ni2P clusters on the outer surface, and the open micropores at the NS-HMOR surface help to prevent their aggregation.

A single layer solid oxide fuel cell composed of La2NiO4 and samarium dope ceria (SDC)-(Li0.67Na0.33)2CO3 is fabricated and characterized. La2NiO4 shows a K2NiF4 structure in an oxidizing atmosphere, and is decomposed to Ni and La2O3 in a reducing atmosphere at the operating temperature of the cell. The electrical conductivity of the composite material increases with the increase of the content of La2NiO4. At 700 °C, the single cell composed of 30 wt.% La2NiO4 and 70 wt.% SDC-(Li0.67Na0.33)2CO3 exhibits the highest power output of 340 and 331 mW cm−2 with H2 and methanol as fuels, respectively. The stability of the cell with H2 and methanol as the fuels is investigated.

Water molecules have been reported to cause the degradation of perovskite crystals by forming a hydrated intermediate structure and then lead iodide irreversibly. Here, the quality of fully crystallized perovskite films is found to be improved by spraying water vapor with an appropriate time. Moreover, this healing effect was found to be reversible and would disappear when the water molecules escaped. Through measuring the steady-state and time-resolved photoluminescence of perovskite film before and after water vapor spray, we found that water molecules can deactivate the nonradiative recombination centers due to hydrogen bonding with uncoordinated ions on the surface of perovskite film. Furthermore, by analyzing the capacitance of devices without and with water vapor spray, the healing or deactivation effect was clearly seen in the significantly decreased density of defect states. This work emphasized the effectiveness of hydroxyl to heal the defects due to dangling bonds on the material surface, and cl...

The role of a SnO 2 -samarium doped ceria (SDC) additional anode layer in a direct carbon fuel cell (DCFC) with SDC-(Li 0.67 Na 0.33 ) 2 CO 3 composite electrolyte and lithiated NiO-SDC-(Li 0.67 Na 0.33 ) 2 CO 3 composite cathode is investigated and compared with a NiO-SDC extra anode layer. Catalytic grown carbon fiber mixed with (Li 0.67 Na 0.33 ) 2 CO 3 is used as a fuel. At 750 °C, the maximum power outputs of 192 and 143 mW cm −2 are obtained by the cells with SnO 2 -SDC and NiO-SDC layers, respectively. In the SnO 2 -SDC layer, the reduction of SnO 2 and the oxidation of Sn happen simultaneously during the cell operation, and the Sn/SnO 2 redox cycle provides an additional route for fuel conversion. The formation of an insulating dense interlayer between the anode and electrolyte layers, which usually happens in DCFCs with metal anodes, is avoided in the cell with the SnO 2 -SDC layer, and the stability of the cell is improved consequently.

Organometal halide perovskite solar cells (PSCs) have emerged as one of the most promising photovoltaic technologies with efficiencies exceeding 20.3%. However, device stability problems including hysteresis in current–voltage scans must be resolved before the commercialization of PSCs. Transient absorption measurements and first-principles calculations indicate that the migration of oxygen vacancies in the TiO2 electrode under electric field during voltage scans contributes to the anomalous hysteresis in PSCs. The accumulation of oxygen vacancies at the electrode/perovskite interface slows down charge extraction while significantly speeding up charge recombination at the interface. Moreover, nonadiabatic molecular dynamics simulations reveal that the charge recombination rates at the interface depend sensitively (with 1 order of magnitude difference) on the locations of oxygen vacancies. By intentionally reducing oxygen vacancies in the TiO2 electrode, we substantially suppress unfavorable hysteresis in ...

Double perovskite, Sr2Fe2−xMoxO6−δ (SFMO), as an anode material of the solid oxide fuel cell (SOFC) exhibits excellent performance. The effects of the substitution ratio of Mo on its properties and electro-catalytic activity are examined. The SFMO anode shows a porous structure with a pore size of several micrometers. Using hydrogen and dry methanol as the fuels, the single cell with the SFMO anode with x between 0.4 and 0.6 gives the maximum power outputs of 541 and 387 mW cm−2 at 1073 K, respectively. The electro-catalytic activity of SFMO anodes exhibits an order of Sr2Fe1.4Mo0.6O6−δ > Sr2Fe1.5Mo0.5O6−δ > Sr2Fe1.6Mo0.4O6−δ. However, the overall conductivity of SFMO displays a reverse order. With the increase of the Mo content, the surface Fe2+/Fe3+ ratio increases regularly, but the Mo5+/Mo6+ radio shows a peak in Sr2Fe1.5Mo0.5O6−δ. It is concluded that the electro-activity of the SFMO anodes for the electro-oxidation of hydrogen and methanol is not limited by their conductivity, but their surface Fe2+/Fe3+ redox couple.