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The ability to intercalate guest species into the van der Waals gap of 2D layered materials affords the opportunity to engineer the electronic structures for a variety of applications. Here we demonstrate the continuous tuning of layer vertically aligned MoS ₂ nanofilms through electrochemical intercalation of Li ⁺ ions. By scanning the Li intercalation potential from high to low, we have gained control of multiple important material properties in a continuous manner, including tuning the oxidation state of Mo, the transition of semiconducting 2H to metallic 1T phase, and expanding the van der Waals gap until exfoliation. Using such nanofilms after different degree of Li intercalation, we show the significant improvement of the hydrogen evolution reaction activity. A strong correlation between such tunable material properties and hydrogen evolution reaction activity is established. This work provides an intriguing and effective approach on tuning electronic structures for optimizing the catalytic activity.

The corrosive anions (e.g., Cl − ) have been recognized as the origins to cause severe corrosion of anode during seawater electrolysis, while in experiments it is found that natural seawater (~0.41 M Cl − ) is usually more corrosive than simulated seawater (~0.5 M Cl − ). Here we elucidate that besides Cl − , Br − in seawater is even more harmful to Ni-based anodes because of the inferior corrosion resistance and faster corrosion kinetics in bromide than in chloride. Experimental and simulated results reveal that Cl − corrodes locally to form narrow-deep pits while Br − etches extensively to generate shallow-wide pits, which can be attributed to the fast diffusion kinetics of Cl − and the lower reaction energy of Br − in the passivation layer. Additionally, for the Ni-based electrodes with catalysts (e.g., NiFe-LDH) loading on the surface, Br − causes extensive spalling of the catalyst layer, resulting in rapid performance degradation. This work clearly points out that, in addition to anti-Cl − corrosion, designing anti-Br − corrosion anodes is even more crucial for future application of seawater electrolysis. It is known that chloride anions cause severe anode corrosion during seawater electrolysis. Here we found that bromide in seawater is even more harmful to Ni-based anodes, causing the spalling of the catalyst layer and the formation of shallow-wide pits on the substrate, leading to performance degradation.

Tungsten carbide is one of the most promising electrocatalysts for the hydrogen evolution reaction, although it exhibits sluggish kinetics due to a strong tungsten-hydrogen bond. In addition, tungsten carbide’s catalytic activity toward the oxygen evolution reaction has yet to be reported. Here, we introduce a superaerophobic nitrogen-doped tungsten carbide nanoarray electrode exhibiting high stability and activity toward hydrogen evolution reaction as well as driving oxygen evolution efficiently in acid. Nitrogen-doping and nanoarray structure accelerate hydrogen gas release from the electrode, realizing a current density of −200 mA cm −2 at the potential of −190 mV vs. reversible hydrogen electrode, which manifest one of the best non-noble metal catalysts for hydrogen evolution reaction. Under acidic conditions (0.5 M sulfuric acid), water splitting catalyzed by nitrogen-doped tungsten carbide nanoarray starts from about 1.4 V, and outperforms most other water splitting catalysts. Water electrolysis can generate carbon-neutral hydrogen gas from water, yet the required catalysts are often expensive, scarce, and poor at gas release. Here, the authors prepared nitrogen-doped carbon tungstide nanoarrays with high water-splitting activities and bubble-releasing surfaces.

Elucidating the structure-property relationship is crucial for the design of advanced electrocatalysts towards the production of hydrogen peroxide (H 2 O 2 ). In this work, we theoretically and experimentally discovered that atomically dispersed Lewis acid sites (octahedral M–O species, M = aluminum (Al), gallium (Ga)) regulate the electronic structure of adjacent carbon catalyst sites. Density functional theory calculation predicts that the octahedral M–O with strong Lewis acidity regulates the electronic distribution of the adjacent carbon site and thus optimizes the adsorption and desorption strength of reaction intermediate (*OOH). Experimentally, the optimal catalyst (oxygen-rich carbon with atomically dispersed Al, denoted as O-C(Al)) with the strongest Lewis acidity exhibited excellent onset potential (0.822 and 0.526 V versus reversible hydrogen electrode at 0.1 mA cm −2 H 2 O 2 current in alkaline and neutral media, respectively) and high H 2 O 2 selectivity over a wide voltage range. This study provides a highly efficient and low-cost electrocatalyst for electrochemical H 2 O 2 production. H 2 O 2 production via oxygen reduction offers a renewable approach to obtain an often-used oxidant. Here, authors show the incorporation of Lewis acid sites into carbon-based materials to improve H 2 O 2 electrosynthesis.

Developing earth-abundant, active and stable electrocatalysts which operate in the same electrolyte for water splitting, including oxygen evolution reaction and hydrogen evolution reaction, is important for many renewable energy conversion processes. Here we demonstrate the improvement of catalytic activity when transition metal oxide (iron, cobalt, nickel oxides and their mixed oxides) nanoparticles (∼20 nm) are electrochemically transformed into ultra-small diameter (2–5 nm) nanoparticles through lithium-induced conversion reactions. Different from most traditional chemical syntheses, this method maintains excellent electrical interconnection among nanoparticles and results in large surface areas and many catalytically active sites. We demonstrate that lithium-induced ultra-small NiFeO x nanoparticles are active bifunctional catalysts exhibiting high activity and stability for overall water splitting in base. We achieve 10 mA cm −2 water-splitting current at only 1.51 V for over 200 h without degradation in a two-electrode configuration and 1 M KOH, better than the combination of iridium and platinum as benchmark catalysts. There is intensive research underway in developing electrocatalysts for water splitting. Here, the authors present a lithium-induced conversion reaction method to develop an active and stable bifunctional catalyst for overall water splitting, outperforming the combination of noble metal catalysts.

Searching for low-cost and efficient catalysts for the oxygen evolution reaction has been actively pursued owing to its importance in clean energy generation and storage. While developing new catalysts is important, tuning the electronic structure of existing catalysts over a wide electrochemical potential range can also offer a new direction. Here we demonstrate a method for electrochemical lithium tuning of catalytic materials in organic electrolyte for subsequent enhancement of the catalytic activity in aqueous solution. By continuously extracting lithium ions out of LiCoO 2 , a popular cathode material in lithium ion batteries, to Li 0.5 CoO 2 in organic electrolyte, the catalytic activity is significantly improved. This enhancement is ascribed to the unique electronic structure after the delithiation process. The general efficacy of this methodology is demonstrated in several mixed metal oxides with similar improvements. The electrochemically delithiated LiCo 0.33 Ni 0.33 Fe 0.33 O 2 exhibits a notable performance, better than the benchmark iridium/carbon catalyst. Lithium cobalt oxide is widely studied for electrocatalytic applications. Here, the authors develop a technique for delithiating the material in organic electrolyte, and demonstrate that the oxygen evolution catalytic activity is significantly improved after the treatment.

Aspirin may be necessary for some patients with cardiovascular disease, but previous studies on the use and dosage of aspirin and the association with hypertension have been inadequate. The results of existing studies have been somewhat inconsistent. Our study was designed to assess the association between prophylactic aspirin use and hypertension in U.S. adults. This cross-sectional study analyzed a nationally representative sample of U.S. adults aged 40 and older from the National Health and Nutrition Examination Survey (2011–2018). Aspirin was categorized as no use, low dose (≤ 100 mg), and high dose (> 100 mg). Hypertension was defined as the average of three consecutive blood pressure readings (systolic ≥ 140 mmHg or diastolic ≥ 90 mmHg). There were 5297 participants, comprising 52.5% male and 47.4% female. The median age was 64 years (range: 56 to 72) and 3635 individuals were diagnosed with high blood pressure. Among the groups, the incidence of hypertension was 70.2% in the non-aspirin group, 68.3% in the low-dose group, and 68.0% in the high-dose group, with no statistically significant difference observed (p = 0.71). Using a fully adjusted weighted multivariate logistic regression model 4, prophylactic aspirin use was not associated with hypertension [(odds ratio [OR] 1.11; 95% CI (0.89–1.38), (odds ratio [OR] 1.15; 95% CI 0.82–1.61), P = 0.31]. Subgroup analyses, along with sensitivity analyses that excluded patients with diabetes and reclassified aspirin use status, confirmed the findings of the main study. In this nationally representative cohort of U.S. adults, no significant association was found between aspirin use or dosage and the prevalence of hypertension.

Previously reported examples of electrochemical pseudocapacitors based on cheap metal oxides have suffered from the need to compromise between specific capacitance, rate capacitance, and reversibility. Here we show that NiO nanorod arrays on Ni foam have a combination of ultrahigh specific capacitance （2018 F/g at 2.27 A/g）, high power density （1536 F/g at 22.7 A/g）, and good cycling stability （only 8% of capacitance was lost in the first 100 cycles with no further change in the subsequent 400 cycles）. This resulted in an improvement in the reversible capacitance record for NiO by 50% or more, reaching 80% of the theoretical value, and demonstrated that a three-dimensional regular porous array structure can afford all of these virtues in a supercapacitor. The excellent performance can be attributed to the slim （〈 20 nm） rod morphology, high crystallinity, regularly aligned array structure and strong bonding of the nanorods to the metallic Ni substrate, as revealed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）.

Background TIR domain containing adaptor molecule 1 (TICAM1) is a coding gene participating in immune and inflammation responses to malignant cells. However, the role of TICAM1 in Wilms tumor (WT) is rarely known. Materials and methods The expression level of TICAM1 was calculated in the WT TARGET cohort and validated using the GSE66405 cohort. The Kaplan–Meier method was employed to investigate the potential clinical value of TICAM1 and the association between its expression level and clinical features. The influence of TICAM1 on immune infiltration was examined by ESTIMATE, CIBERSORT and MCPcounter algorithms. IC50 of chemotherapeutic drugs was calculated by “pRRophetic” R package. Results TICAM1 was downregulated in WT patients with worse prognosis and a more advanced clinical stage. Moreover, a low expression level of TICAM1 contributed to less immune cell infiltration, few protective immune cells and more antitumor immune cells. Conclusions TICAM1 exerts a significant impact on the prognosis, progression and immune infiltration condition of WT.

Electrochemical intercalation of ions into the van der Waals gap of two-dimensional (2D) layered materials is a promising low-temperature synthesis strategy to tune their physical and chemical properties. It is widely believed that ions prefer intercalation into the van der Waals gap through the edges of the 2D flake, which generally causes wrinkling and distortion. Here we demonstrate that the ions can also intercalate through the top surface of few-layer MoS 2 and this type of intercalation is more reversible and stable compared to the intercalation through the edges. Density functional theory calculations show that this intercalation is enabled by the existence of natural defects in exfoliated MoS 2 flakes. Furthermore, we reveal that sealed-edge MoS 2 allows intercalation of small alkali metal ions ( e.g ., Li + and Na + ) and rejects large ions (e.g., K + ). These findings imply potential applications in developing functional 2D-material-based devices with high tunability and ion selectivity. Electrochemical ion intercalation in 2D layered materials is known to occur through the material’s edges, accompanied by frequent structural deformations. Here the authors show that in MoS2 flakes where the edges have been sealed, a reversible and ion-selective intercalation occurs through the top surface via the intrinsic defects.