Abstract
Single-atom catalysts have been widely investigated for several electrocatalytic reactions except electrochemical alcohol oxidation. Herein, we synthesize atomically dispersed platinum on ...ruthenium oxide (Pt
1
/RuO
2
) using a simple impregnation-adsorption method. We find that Pt
1
/RuO
2
has good electrocatalytic activity towards methanol oxidation in an alkaline media with a mass activity that is 15.3-times higher than that of commercial Pt/C (6766 vs. 441 mA mg
‒1
Pt
). In contrast, single atom Pt on carbon black is inert. Further, the mass activity of Pt
1
/RuO
2
is superior to that of most Pt-based catalysts previously developed. Moreover, Pt
1
/RuO
2
has a high tolerance towards CO poisoning, resulting in excellent catalytic stability. Ab initio simulations and experiments reveal that the presence of Pt‒O
3f
(3-fold coordinatively bonded O)‒Ru
cus
(coordinatively unsaturated Ru) bonds with the undercoordinated bridging O in Pt
1
/RuO
2
favors the electrochemical dehydrogenation of methanol with lower energy barriers and onset potential than those encountered for Pt‒C and Pt‒Ru.
Rechargeable sodium metal batteries with high energy density could be important to a wide range of energy applications in modern society. The pursuit of higher energy density should ideally come with ...high safety, a goal difficult for electrolytes based on organic solvents. Here we report a chloroaluminate ionic liquid electrolyte comprised of aluminium chloride/1-methyl-3-ethylimidazolium chloride/sodium chloride ionic liquid spiked with two important additives, ethylaluminum dichloride and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide. This leads to the first chloroaluminate based ionic liquid electrolyte for rechargeable sodium metal battery. The obtained batteries reached voltages up to ~ 4 V, high Coulombic efficiency up to 99.9%, and high energy and power density of ~ 420 Wh kg
and ~ 1766 W kg
, respectively. The batteries retained over 90% of the original capacity after 700 cycles, suggesting an effective approach to sodium metal batteries with high energy/high power density, long cycle life and high safety.
Engineering single-atom electrocatalysts with high-loading amount holds great promise in energy conversion and storage application. Herein, we report a facile and economical approach to achieve an ...unprecedented high loading of single Ir atoms, up to ∼18wt%, on the nickel oxide (NiO) matrix as the electrocatalyst for oxygen evolution reaction (OER). It exhibits an overpotential of 215 mV at 10 mA cm–2 and a remarkable OER current density in alkaline electrolyte, surpassing NiO and IrO2 by 57 times and 46 times at 1.49 V vs RHE, respectively. Systematic characterizations, including X-ray absorption spectroscopy and aberration-corrected Z-contrast imaging, demonstrate that the Ir atoms are atomically dispersed at the outermost surface of NiO and are stabilized by covalent Ir–O bonding, which induces the isolated Ir atoms to form a favorable ∼4+ oxidation state. Density functional theory calculations reveal that the substituted single Ir atom not only serves as the active site for OER but also activates the surface reactivity of NiO, which thus leads to the dramatically improved OER performance. This synthesis method of developing high-loading single-atom catalysts can be extended to other single-atom catalysts and paves the way for industrial applications of single-atom catalysts.
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IJS, KILJ, NUK, PNG, UL, UM
The intestine is a highly radiosensitive tissue that is susceptible to structural and functional damage due to systemic as well as localized radiation exposure. Unfortunately, no effective ...prophylactic or therapeutic agents are available at present to manage radiation-induced intestinal injuries. We observed that the vanillin derivative VND3207 improved the survival of lethally irradiated mice by promoting intestinal regeneration and increasing the number of surviving crypts. Pre-treatment with VND3207 significantly increased the number of Lgr5+ intestinal stem cells (ISCs) and their daughter cells, the transient Ki67+ proliferating cells. Mechanistically, VND3207 decreased oxidative DNA damage and lipid peroxidation and maintained endogenous antioxidant status by increasing the level of superoxide dismutase and total antioxidant capacity. In addition, VND3207 maintained appropriate levels of activated p53 that triggered cell cycle arrest but were not sufficient to induce NOXA-mediated apoptosis, thus ensuring DNA damage repair in the irradiated small intestinal crypt cells. Furthermore, VND3207 treatment restores the intestinal bacterial flora structures altered by TBI exposure. In conclusion, VND3207 promoted intestinal repair following radiation injury by reducing reactive oxygen species-induced DNA damage and modulating appropriate levels of activated p53 in intestinal epithelial cells.
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•VND3207 improves survival and mitigates intestinal injury in lethally irradiated mice.•VND3207 augments proliferation and survival of intestinal stem cells in irradiated mice.•VND3207 downregulates IR-induced activation of p53/Noxa signaling in intestinal crypts.•VND3207 treatment restores the intestinal bacterial flora structures altered by TBI exposure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The p53‐inducible gene 3 (PIG3) is one of the p53‐induced genes at the onset of apoptosis, which plays an important role in cell apoptosis and DNA damage response. Our previous study reported an ...oncogenic role of PIG3 associated with tumor progression and metastasis in non‐small cell lung cancer (NSCLC). In this study, we further analyzed PIG3 mRNA expression in 504 lung adenocarcinoma (LUAD) and 501 lung squamous cell carcinoma (LUSC) tissues from The Cancer Genome Atlas database and we found that PIG3 expression was significantly higher in LUAD with lymph node metastasis than those without, while no difference was observed between samples with and without lymph node metastasis in LUSC. Gain and loss of function experiments were performed to confirm the metastatic role of PIG3 in vitro and to explore the mechanism involved in its oncogenic role in NSCLC metastasis. The results showed that PIG3 knockdown significantly inhibited the migration and invasion ability of NSCLC cells, and decreased paxillin, phospho‐focal adhesion kinase (FAK) and phospho‐Src kinase expression, while its overexpression resulted in the opposite effects. Blocking FAK with its inhibitor reverses PIG3 overexpression‐induced cell motility in NSCLC cells, indicating that PIG3 increased cell metastasis through the FAK/Src/paxillin pathway. Furthermore, PIG3 silencing sensitized NSCLC cells to FAK inhibitor. In conclusion, our data revealed a role for PIG3 in inducing LUAD metastasis, and its role as a new FAK regulator, suggesting that it could be considered as a novel prognostic biomarker or therapeutic target in the treatment of LUAD metastasis.
Our data demonstrated that PIG3 might function as a FAK regulator in NSCLC and could serve as a novel prognostic biomarker or therapeutic target in the treatment of NSCLC metastasis. This evidence will further help scientists to understand NSCLC progression and to develop new therapeutic strategies.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Rechargeable lithium metal batteries are next generation energy storage devices with high energy density, but face challenges in achieving high energy density, high safety, and long cycle life. Here, ...lithium metal batteries in a novel nonflammable ionic‐liquid (IL) electrolyte composed of 1‐ethyl‐3‐methylimidazolium (EMIm) cations and high‐concentration bis(fluorosulfonyl)imide (FSI) anions, with sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) as a key additive are reported. The Na ion participates in the formation of hybrid passivation interphases and contributes to dendrite‐free Li deposition and reversible cathode electrochemistry. The electrolyte of low viscosity allows practically useful cathode mass loading up to ≈16 mg cm−2. Li anodes paired with lithium cobalt oxide (LiCoO2) and lithium nickel cobalt manganese oxide (LiNi0.8Co0.1Mn0.1O2, NCM 811) cathodes exhibit 99.6–99.9% Coulombic efficiencies, high discharge voltages up to 4.4 V, high specific capacity and energy density up to ≈199 mAh g−1 and ≈765 Wh kg−1 respectively, with impressive cycling performances over up to 1200 cycles. Highly stable passivation interphases formed on both electrodes in the novel IL electrolyte are the key to highly reversible lithium metal batteries, especially for Li–NMC 811 full batteries.
A nonflammable ionic‐liquid electrolyte is developed for high‐safety and high‐energy‐density Li metal batteries, allowing practically useful cathode mass loading up to 16 mg cm−2, realizing high specific capacity and energy density (199 mAh g−1 and 765 Wh kg−1) with impressive cycling performances. The robust passivation interphases formed on both electrodes are key to realizing impressive battery performances.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
LiNi
Mn
Co
O
-layered cathode is often fabricated in the form of secondary particles, consisting of densely packed primary particles. This offers advantages for high energy density and alleviation of ...cathode side reactions/corrosions, but introduces drawbacks such as intergranular cracking. Here, we report unexpected observations on the nucleation and growth of intragranular cracks in a commercial LiNi
Mn
Co
O
cathode by using advanced scanning transmission electron microscopy. We find the formation of the intragranular cracks is directly associated with high-voltage cycling, an electrochemically driven and diffusion-controlled process. The intragranular cracks are noticed to be characteristically initiated from the grain interior, a consequence of a dislocation-based crack incubation mechanism. This observation is in sharp contrast with general theoretical models, predicting the initiation of intragranular cracks from grain boundaries or particle surfaces. Our study emphasizes that maintaining structural stability is the key step towards high-voltage operation of layered-cathode materials.
Developing low cost and highly active catalysts for the oxygen evolution reaction (OER) in an acidic medium is urgently indispensable for proton exchange membrane water electrolyzers (PEMWEs). ...Herein, we have prepared ultra-thin RuO
2
nanosheets (RuO
2
NSs) using a simple molten salt method. The as-prepared RuO
2
NSs with a thickness of 1-2 nm possess abundant defects. Toward the OER, the RuO
2
NSs achieve an extremely low overpotential of 199 mV at a current density of 10 mA cm
geo
−2
with a loading of 125 μg cm
geo
−2
. Furthermore, the RuO
2
NSs exhibit specific and mass activities of up to 0.89 mA cm
oxide
−2
and 0.52 A mg
Ru
−1
at 1.46 V
vs.
RHE, which are 14.9 and 80.6 times enhanced in specific and mass activity as compared to the commercial RuO
2
nanoparticles, respectively. In a homemade PEMWE, with RuO
2
NSs as the OER catalyst, the electrolyzer achieves a current density of 0.93 A cm
−2
at a cell voltage of 1.65 V without
iR
drop correction, which is 3 times larger than that of the commercial RuO
2
catalyst (0.31 A cm
−2
). Density functional theory calculations indicate that the Ru vacancy on the RuO
2
NS surfaces significantly weakens the binding energy of O* with respect to that of OOH*, which decreases the energy cost in the transformation from O* to OOH*, and thus dramatically enhances the OER performance. The unique defect-rich structure and outstanding performance demonstrate that the RuO
2
NSs possess great potential for developing high-performance PEMWEs.
A Ru vacancy decreases the energy barrier from O* to OOH*, thus dramatically enhancing the OER performance of defect-rich RuO
2
nanosheets.
Developing efficient and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is highly desired for the hydrogen economy. In this study, we developed a facile microwave reduction ...method to synthesize single Pt atoms anchored on aniline-stacked graphene (Pt SASs/AG) with outstanding HER performance. Pt SASs/AG presents excellent HER activity with η = 12 mV at 10 mA cm −2 and a mass current density of 22 400 Ag Pt −1 at η = 50 mV, which is 46 times higher than that of commercial 20 wt% Pt/C. Moreover, the Pt SASs/AG catalyst is highly active and more stable than Pt/C. X-ray absorption fine spectroscopy and density functional theory calculations demonstrated that the coordination of atomically isolated Pt with the nitrogen of aniline optimized the electronic structure of Pt and the hydrogen adsorption energy, eventually promoting HER activity. This study provides a new avenue for the development of single-atom Pt electrocatalysts with high activity and stability.
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