Substrate‐supported metal–organic frameworks (MOFs) films are desired to realize their potential in practical applications. Herein, a novel substrate‐seeding secondary‐growth strategy is developed to ...prepare composites of uniform MOFs films on aerogel walls. Briefly, the organic ligand is “pre‐seeded” onto the aerogel walls, and then a small amount of metal‐ion solution is sprayed onto the prepared aerogel. The sprayed solution diffuses along the aerogel walls to form a continuous thin layer, which confines the nucleation reaction, promoting the formation of uniform MOFs films on the aerogel walls. The whole process is simple in operation, highly efficient, and eco‐friendly. The resulting hierarchical MOFs/aerogel composites have abundant accessible active sites and enable excellent mass transfer, which endows the composite with outstanding catalytic activity and stability in both liquid‐phase CO2 cycloaddition and electrochemical oxygen evolution reaction (OER) process.
Metal–organic framework (MOF) thin films are coated onto the walls of aerogel giving MOFs/aerogel composites. These have abundant accessible active sites and excellent mass transfer ability, and thus a relatively high catalytic activity and stability in the CO2 cycloaddition and oxygen evolution reaction (OER).
In this work, we established a one-step strategy to synthesize three-dimensional porous graphitic biomass carbon (PGBC) from bamboo char (BC), and studied its electrochemical performance as electrode ...materials for supercapacitors. Using potassium ferrate (K
2
FeO
4
) to fulfil the synchronous carbonization and graphitization of bamboo carbon, this method is less time-demanding, highly efficient and pollution-free, when compared with a conventional two-step strategy. The as-prepared PGBC sample possessed a porous structure with a large specific surface area (1732 m
2
g
−1
) and abundant micropores, as well as a high graphitization degree demonstrated by XRD and Raman. Further electrochemical measurements revealed that the PGBC electrode exhibited a high specific capacitance of 222.0 F g
−1
at 0.5 A g
−1
, and the solid-state symmetric supercapacitor in an aqueous electrolyte (KOH/PVA) presented considerable synergetic energy–power output properties with an energy density of 6.68 W h kg
−1
at a power density of 100.2 W kg
−1
, and 3.33 W h kg
−1
at 10 kW kg
−1
. Moreover, the coin-type symmetric supercapacitor in an ionic liquid electrolyte (EMIM TFSI) delivered a higher energy density of 20.6 W h kg
−1
at a power density of 12 kW kg
−1
. This approach holds great promise to achieve low-cost, green and industrial-grade production of renewable biomass-derived carbon materials for advanced energy storage applications in the future.
Lonicerae japonicae flos (called Jinyinhua, JYH in Chinese), flowers or flower buds of
Lonicera japonica
Thunberg, is an extremely used traditional edible-medicinal herb. Pharmacological studies have ...already proved JYH ideal clinical therapeutic effects on inflammation and infectious diseases and prominent effects on multiple targets in vitro and in vivo, such as pro-inflammatory protein inducible nitric oxide synthase, toll-like receptor 4, interleukin-1 receptor. JYH and Lonicerae flos called Shanyinhua, SYH in Chinese, flowers or flower buds of
Lonicera hypoglauca
Miquel,
Lonicera confusa
De Candolle or
Lonicera macrantha
(D.Don) Spreng which belongs to the same family of JYH were once recorded as same herb in multiple versions of Chinese Pharmacopoeia (ChP). However, they were listed as two different herbs in 2005 Edition ChP, leading to endless controversy since they have close proximity on plant species, appearances and functions, together with traditional applications. In the past decades, there has no literature regarding to systematical comparison on the similarity concerning research achievements of the two herbs. This review comprehensively presents similarities and differences between JYH and SYH retrospectively, particularly proposing them the marked differences in botanies, phytochemistry and pharmacological activities which can be used as evidence of separate list of JYH and SYH. Furthermore, deficiencies on present studies have also been discussed so as to further research could use for reference.
Confined microenvironments formed in heterogeneous catalysts have recently been recognized as equally important as catalytically active sites. Understanding the fundamentals of confined catalysis has ...become an important topic in heterogeneous catalysis. Well-defined 2D space between a catalyst surface and a 2D material overlayer provides an ideal microenvironment to explore the confined catalysis experimentally and theoretically. Using density functional theory calculations, we reveal that adsorption of atoms and molecules on a Pt(111) surface always has been weakened under monolayer graphene, which is attributed to the geometric constraint and confinement field in the 2D space between the graphene overlayer and the Pt(111) surface. A similar result has been found on Pt(110) and Pt(100) surfaces covered with graphene. The microenvironment created by coating a catalyst surface with 2D material overlayer can be used to modulate surface reactivity, which has been illustrated by optimizing oxygen reduction reaction activity on Pt(111) covered by various 2D materials. We demonstrate a concept of confined catalysis under 2D cover based on a weak van der Waals interaction between 2D material overlayers and underlying catalyst surfaces.
The influence of variant graphenes on electrochemical performance for supercapacitors was studied comparatively and systematically by using SEM,FTIR and Raman spectroscopy,cyclic ...voltammetry(CV),galvanostatic charge/discharge and electrochemical impedance spectroscopy(EIS).The results revealed that:1) the nitrogen-doped graphene(N-G) electrode exhibited the highest specific capacitance at the same voltage scan rate;2) the specific capacitance of the N-G reached up to 243.5 F/g at 1 A/g,while regular graphite oxide(GO) was 43.5 F/g and reduced graphene oxide(rGO) was 67.9 F/g;3) N-G exhibited the best supercapacitance performance and the superior electrochemical properties,which made it an ideal electrode material for supercapacitors.
Abstract
Metal nanoparticles anchored on perovskite through in situ exsolution under reducing atmosphere provide catalytically active metal/oxide interfaces for CO
2
electrolysis in solid oxide ...electrolysis cell. However, there are critical challenges to obtain abundant metal/oxide interfaces due to the sluggish diffusion process of dopant cations inside the bulk perovskite. Herein, we propose a strategy to promote exsolution of RuFe alloy nanoparticles on Sr
2
Fe
1.4
Ru
0.1
Mo
0.5
O
6−
δ
perovskite by enriching the active Ru underneath the perovskite surface via repeated redox manipulations. In situ scanning transmission electron microscopy demonstrates the dynamic structure evolution of Sr
2
Fe
1.4
Ru
0.1
Mo
0.5
O
6−
δ
perovskite under reducing and oxidizing atmosphere, as well as the facilitated CO
2
adsorption at RuFe@Sr
2
Fe
1.4
Ru
0.1
Mo
0.5
O
6−
δ
interfaces. Solid oxide electrolysis cell with RuFe@Sr
2
Fe
1.4
Ru
0.1
Mo
0.5
O
6−
δ
interfaces shows over 74.6% enhancement in current density of CO
2
electrolysis compared to that with Sr
2
Fe
1.4
Ru
0.1
Mo
0.5
O
6−
δ
counterpart as well as impressive stability for 1000 h at 1.2 V and 800 °C.
A membrane with both high ion conductivity and selectivity is critical to high power density and low-cost flow batteries, which are of great importance for the wide application of renewable energies. ...The trade-off between ion selectivity and conductivity is a bottleneck of ion conductive membranes. In this paper, a thin-film composite membrane with ultrathin polyamide selective layer is found to break the trade-off between ion selectivity and conductivity, and dramatically improve the power density of a flow battery. As a result, a vanadium flow battery with a thin-film composite membrane achieves energy efficiency higher than 80% at a current density of 260 mA cm
, which is the highest ever reported to the best of our knowledge. Combining experiments and theoretical calculation, we propose that the high performance is attributed to the proton transfer via Grotthuss mechanism and Vehicle mechanism in sub-1 nm pores of the ultrathin polyamide selective layer.
The only feasible access to non‐face‐centered cubic (FCC) copper was by physical vapor deposition under high vacuum. Now, non‐FCC copper is observed in a series of alkynyl‐protected Cu53 nanoclusters ...(NCs) obtained from solution‐phase synthesis. Determined by single‐crystal X‐ray crystallography, the structures of Cu53(C≡CPhPh)9(dppp)6Cl3(NO3)9 and its two derivatives reveal an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, which gives strong evidence that Cu can be arranged in non‐FCC lattice at ambient conditions when proper ligands are provided. Characterization methods including X‐ray absorption fine structure, XPS, ESI‐MS, UV/Vis, Auger spectroscopy, and DFT calculations were carried out. CuII was shown to successively coordinate with introduced ligands and changed to CuI after bonding with phosphine. The following addition of NaBH4 and the aging step further reduced it to the Cu53 NC.
Face‐OFF: Non‐FCC copper is observed in a series of alkynyl‐protected Cu53 nanoclusters (NCs) obtained from solution‐phase synthesis. Cu53 and its two derivatives reveal an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, giving strong evidence that Cu can be arranged in a non‐FCC lattice under ambient conditions when proper ligands are provided.
Objective： This review aimed to provide a current recommendation to multidisciplinary physicians for early detection, diagnosis, and treatment of corticosteroid-induced osteonecrosis of the femoral ...head （ONFH） based on a comprehensive analysis of the clinical literature. Data Sources： For the purpose of collecting potentially eligible articles, we searched for articles in the PubMed, Cochrane Library, Embase, and CNKI databases up to February 2017, using the following key words： ＆quot;corticosteroid＆quot;, ＆quot;osteonecrosis of the femoral head＆quot;,＆quot;risk factors＆quot;, ＆quot;diagnosis＆quot;, ＆quot;prognosis＆quot;, and ＆quot;treatment＆quot;. Study Selection： Articles on relationships between corticosteroid and ONFH were selected for this review. Articles on the diagnosis, prognosis, and intervention of earlier-stage ONFH were also reviewed. Results： The incidence of corticosteroid-induced ONFH was associated with high doses of corticosteroids, and underlying diseases in certain predisposed individuals mainly occurred in the first 3 months of corticosteroid prescription. The enhanced awareness and minimized exposure to the established risk factors and earlier definitive diagnosis are essential for the success of joint preservation. When following up patients with ONFH, treatment should be started if necessary. Surgical treatment yielded better results than conservative therapy in earlier-stage ONFH. The ideal purpose of earlier intervention and treatment is permanent preservation of the femoral head without physical restrictions in daily living. Conclusions： Clinicians should enhance their precaution awareness of corticosteroid-induced ONFH. For high-risk patients, regular follow-up is very important in the 1st year after high-dose prescription of corticosteroids. Patients with suspected ONFH should be referred to orthopedists for diagnosis and treatment in its earlier stage to preserve the joint.
Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock‐like structures at the molecular level. In ...this work, we report the cocrystallization of two structurally related atom‐precise fcc silver nanoclusters Ag110(SPhF)48(PPh3)12 (Ag110) and Ag14(μ6‐S)(SPhF)12(PPh3)8 (Ag14). It is worth noting that the Ag110 cluster is the first compound to simulate the complex Luban lock structure at the molecular level. Meanwhile, Ag110 is the largest known fcc‐based silver nanocluster, so far, there is no precedent for fcc silver nanocluster with more than 100 silver atoms. DFT calculations show that Ag110 is a 58‐electron superatom with an electronically closed shell1S21P61D102S21F142P61G18. Ag110⋅Ag14 can rapidly catalyze the reduction of 4‐nitrophenol within 4 minutes. In addition, Ag110 presents clear structural evidence to reveal the critical size and mechanism of the transformation of metal core from fcc stacking to quasi‐spherical superatom. This research work provides an important structural model for studying the nucleation mechanism and structural assembly of silver nanoclusters.
Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock‐like structures at the molecular level. In this work, we report the cocrystallization of two structurally homologous atom‐precise fcc silver nanoclusters Ag110(SPhF)48(PPh3)12 (Ag110) and Ag14(μ6‐S)(SPhF)12(PPh3)8 (Ag14). The Ag110 cluster is the first compound to simulate the complex Luban lock structure at the molecular level.
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