The exploration of efficient electrocatalysts is the central issue for boosting the overall efficiency of water splitting. Herein, pertinently creating active sites and improving conductivity for ...metal–organic frameworks (MOFs) is proposed to tailor electrocatalytic properties for overall water splitting. An Ni(II)‐MOF nanosheet array is presented as an ideal material model and a facile alkali‐etched strategy is developed to break its NiO bonds accompanied with the introduction of extra‐framework K cations, which contribute to creating highly active open metal sites and largely improving the electrical conductivity. As a result, the assembled defect‐Ni‐MOF||defect‐Ni‐MOF electrolyte cell delivers a lower and stable voltage of 1.50 V at 10 mA cm−2 in alkaline medium for overall water splitting, comparable to the combination of iridium and platinum as benchmark catalysts.
The introduction of defects into metal–organic framework (MOF) by alkali‐etching treatment to create rich active sites and tailor electrical conductivity is proposed. The resultant defect‐rich Ni(II)‐MOF nanosheet array exhibits excellent electrocatalytic overall water splitting performance, comparable to the noble metal‐based benchmark catalysts.
Despite numerous inherent merits of metal–organic frameworks (MOFs), structural fragility has imposed great restrictions on their wider involvement in many applications, such as in catalysis. Herein, ...a strategy for enhancing stability and enabling functionality in a labile Zr(IV)‐MOF has been proposed by in situ porphyrin substitution. A size‐ and geometry‐matched robust linear porphyrin ligand 4,4′‐(porphyrin‐5,15‐diyl)dibenzolate (DCPP2−) is selected to replace the 4,4′‐(1,3,6,8‐tetraoxobenzolmn3,8phenanthroline‐2,7(1H,3H,6H,8H)‐diyl)dibenzoate (NDIDB2−) ligand in the synthesis of BUT‐109(Zr), affording BUT‐110 with varied porphyrin contents. Compared to BUT‐109(Zr), the chemical stability of BUT‐110 series is greatly improved. Metalloporphyrin incorporation endows BUT‐110 MOFs with high catalytic activity in the photoreduction of CO2, in the absence of photosensitizers. By tuning the metal species and porphyrin contents in BUT‐110, the resulting BUT‐110‐50%‐Co is demonstrated to be a good photocatalyst for selective CO2‐to‐CO reduction, via balancing the chemical stability, photocatalytic efficiency, and synthetic cost. This work highlights the advantages of in situ ligand substitution for MOF modification, by which uniform distribution and high content of the incoming ligand are accessible in the resulting MOFs. More importantly, it provides a promising approach to convert unstable MOFs, which mainly constitute the vast MOF database but have always been neglected, into robust functional materials.
The in situ porphyrin substitution strategy is developed for modifying labile interpenetrated BUT‐109(Zr), affording BUT‐110 with enhanced chemical stability and photocatalytic activity. By tuning the species and contents of metalloporphyrin in BUT‐110, some of the BUT‐110 MOFs may serve as potential photocatalysts for selective CO2‐to‐CO reduction, in the absence of photosensitizer.
Abstract
Background
Frailty is an age-related clinical syndrome of decreased resilience to stressors and is associated with numerous adverse outcomes. Although there is preponderance of literature on ...frailty in developed countries, limited investigations have been conducted in less developed regions including China—a country that has the world’s largest aging population. We examined frailty prevalence in China by sociodemographics and geographic region, and investigated correlates of frailty.
Methods
Participants were 5,301 adults aged ≥60 years from the China Health and Retirement Longitudinal Study. Frailty was identified by the validated physical frailty phenotype (PFP) scale. We estimated frailty prevalence in the overall sample and by sociodemographics. We identified age-adjusted frailty prevalence by geographical region. Bivariate associations of frailty with health and function measures were evaluated by chi-squared test and analysis of variance.
Results
We found 7.0% of adults aged 60 years or older were frail. Frailty is more prevalent at advanced ages, among women, and persons with low education. Age-adjusted frailty prevalence ranged from 3.3% in the Southeast and the Northeast to 9.1% in the Northwest, and was more than 1.5 times higher in rural versus urban areas. Frail versus nonfrail persons had higher prevalence of comorbidities, falls, disability, and functional limitation.
Conclusions
We demonstrated the utility of the PFP scale in identifying frail Chinese elders, and found substantial sociodemographic and regional disparities in frailty prevalence. The PFP scale may be incorporated into clinical practice in China to identify the most vulnerable elders to reduce morbidity, prevent disability, and enable more efficient use of health care resources.
Exploring novel multifunctional rare earth materials is very important because these materials have fundamental interests, such as new structural facts and connecting modes, as well as potential ...technological applications, including optics, magnetic properties, sorption, and catalytic behaviors. Especially, employing these nanomaterials for sensing or catalytic reactions is still very challenging. Herein, a new superstable, anionic terbium‐metal–organic‐framework, H2N(CH3)2Tb(cppa)2(H2O)2, (China Three Gorges University (CTGU‐1), H2cppa = 5‐(4‐carboxyphenyl)picolinic acid), is successfully prepared, which can be used as a turn‐on, highly‐sensitive fluorescent sensor to detect Eu3+ and Dy3+, with a detection limitation of 5 × 10−8 and 1 × 10−4m in dimethylformamide, respectively. This result represents the first example of lanthanide‐metal–organic‐frameworks (Ln‐MOF) that can be employed as a discriminative fluorescent probe to recognize Eu3+ and Dy3+. In addition, through ion exchanging at room temperature, Ag(I) can be readily reduced in situ and embedded in the anionic framework, which leads to the formation of nanometal‐particle@Ln‐MOF composite with uniform size and distribution. The as‐prepared Ag@CTGU‐1 shows remarkable catalytic performance to reduce 4‐nitrophenol, with a reduction rate constant κ as large as 2.57 × 10−2 s−1; almost the highest value among all reported noble‐metal‐nanoparticle@MOF composites.
A new porous, anionic Tb‐metal–organic‐framework, China Three Gorges University (CTGU‐1), can serve as a turn‐on sensor for detection of Eu3+ and Dy3+, with different detection limits. Additionally, spontaneous in situ reduction and immobilization of ion‐exchanged Ag(I) to Ag nanoparticles in the anionic framework result in an Ag@CTGU‐1 composite, which can remarkably catalyze the reduction of 4‐nitrophenol.
Designing efficient multifunctional electrocatalysts for water and urea splitting to produce green hydrogen presents a significant yet worthwhile challenge. Herein, the morphology and electronic ...structure of cobalt metaphosphate (Co2P4O12) by vanadium (V) doping, resulting in improved electrocatalytic activity and stability for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR) are simultaneously regulated. Theory calculations show that V‐doped Co2P4O12 (V‐Co2P4O12) can boost the kinetics of catalytic reactions by optimizing the d‐band center of Co atoms and the binding strength of intermediates, as well as enhancing the density of states. Moreover, the doping of V into Co2P4O12 crystalline structure benefits the formation of a thicker amorphous layer during the catalytic process, which could enhance its alkaline corrosion resistance and stability. Additionally, the multilevel nanostructures of V‐Co2P4O12 provide rich active sites for catalytic reactions. As a result, a two‐electrode electrolyzer assembled by V‐doped Co2P4O12 delivers low voltages for overall water and urea splitting. The superior performance suggests that the proposed V‐doping strategy is a promising way to regulate electrocatalytic activity for catering to green electrocatalytic applications.
The morphology and electronic structure of the Co2P4O12 catalyst are simultaneously regulated by V doping, which endows the catalyst with enhanced hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR) performance. Thanks to the excellent trifunctional catalytic performance, the assembled two‐electrode electrolyzers enable efficient overall water and urea splitting at low overpotentials.
Abstract
Background
exposures in childhood and adolescence may impact the development of diseases and symptoms in late life. However, evidence from low- and middle-income countries is scarce. In this ...cross-sectional study, we examined the association of early life risk factors with frailty amongst older adults using a large, nationally representative cohort of community-dwelling Chinese sample.
Methods
we included 6,806 participants aged $\ge$60 years from the China Health and Retirement Longitudinal Study. We measured 13 risk factors in childhood or adolescence through self-reports, encompassing six dimensions (education, family economic status, nutritional status, domestic violence, neighbourhood and health). We used multinomial regression models to examine the association between risk factors and frailty. We further calculated the absolute risk difference for the statistically significant factors.
Results
persons with higher personal and paternal education attainment, better childhood neighbourhood quality and better childhood health status had lower risk of being frail in old age. Severe starvation in childhood was associated with higher risk of prefrailty. The risk differences of being frail were 5.6% lower for persons with a high school or above education, 1.5% lower for those whose fathers were literate, 4.8% lower for the highest neighbourhood quality and 2.9% higher for worse childhood health status compared to their counterparts.
Conclusions
unfavorable socioeconomic status and worse health condition in childhood and adolescence may increase the risk of late-life frailty amongst Chinese older adults.
The development of ethane (C2H6)‐selective adsorbents for ethylene (C2H4) purification, although challenging, is of prime industrial importance. Pillared‐layer metal‐organic frameworks (MOFs) possess ...facilely tunable pore structure and functionality, which means they have excellent potential for high‐performance C2H6/C2H4 separation applications. Herein, we report a family of isostructural pillared‐layer MOFs with various metal centers M and co‐ligands L, M2(D‐cam)4L2 (denoted M‐cam‐L; M = Cu, Co, Ni; L = pyz, apyz, dabco), with a variety of pore surface properties. All of the M‐cam‐L materials exhibit preferential adsorption for C2H6 over C2H4. In particular, Ni‐cam‐pyz exhibits the highest C2H6 capture capacity (68.75 cm3 g−1 at 1 bar and 298 K), Cu‐cam‐dabco possesses the greatest C2H6/C2H4 adsorption selectivity (2.3), and the lowest isosteric heat of adsorption is demonstrated for Cu‐cam‐pyz (20.1 kJ mol−1). Dynamic column breakthrough experiments also confirmed the excellent separation performance of M‐cam‐pyz and M‐cam‐dabco materials. The synthesis route of the M‐cam‐L materials is easily scaled‐up under laboratory conditions, and hence this class of MOFs is promising for practical C2H4 purification.
Constructing stable palladium(II)-based metal–organic frameworks (MOFs) would unlock more opportunities for MOF chemistry, particularly toward applications in catalysis. However, their availability ...is limited by synthetic challenges due to the inertness of the Pd–ligand coordination bond, as well as the strong tendency of the Pd(II) source to be reduced under typical solvothermal conditions. Under the guidance of reticular chemistry, herein, we present the first example of an azolate Pd-MOF, BUT-33(Pd), obtained via a deuterated solvent-assisted metal metathesis. BUT-33(Pd) retains the underlying sodalite network and mesoporosity of the template BUT-33(Ni) and shows excellent chemical stability (resistance to an 8 M NaOH aqueous solution). With rich Pd(II) sites in the atomically precise distribution, it also demonstrates good performances as a heterogeneous Pd(II) catalyst in a wide application scope, including Suzuki/Heck coupling reactions and photocatalytic CO2 reduction to CH4. This work highlights a feasible approach to reticularly construct noble metal based MOFs via metal metathesis, in which various merits, including high chemical stability, large pores, and tunable functions, have been integrated for addressing challenging tasks.
Two new three-dimensional (3D) multinodal Cd(II)–organic frameworks, Cd3(dccpa)(bipy)0.5(H2O)4·5H2O (1) and (CH3)2NH22Cd11(dccpa)4(DMF)4(H2O)8·4H2O (2) (H6dccpa = 3,4-di(3,5-dicarboxyl ...phenyl) phthalic acid, bipy = 4,4′-bipyridine), have been prepared and fully characterized. Compound 1 possesses a 3D neutral framework with a new (6,6,7)-connected topology based on a single trinuclear cluster, while 2 features a 3D anionic framework with a new (5,6,6,10)-connected topology containing mixed trinuclear and pentanuclear clusters. Remarkably, 1 and 2 show promising photocatalytic activities toward the degradation of rhodamine B and methyl blue, which suggests that different kinds of cluster units may exert different impacts on the decomposition of organic dyes.
A new MOF-74(Ni)/NiOOH heterogeneous composite was synthesized via NiOOH microsphere precursor. The electrocatalytic methanol oxidation reactions' (MOR) performance was assessed. The as-prepared ...MOF-74(Ni)/NiOOH exhibited excellent activity with high peak current density (27.62 mA·cm
) and high mass activity (243.8 mA·mg
). The enhanced activity could be a result of the synergistic effect of the MOF-74(Ni)/NiOOH heterocomposite providing more exposed active sites, a beneficial diffusion path between the catalyst surface and electrolyte, and improved conductivity, favorable for improving MOR performance.
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