Transition-metal selenides have attracted sustaining interests as promising anodes for sodium-ion batteries (SIBs) due to the suitable electrochemical storage mechanism. However, the intrinsic ...expansion effect during the electrochemical process restricts their further development, thus their composition engineering aiming at weakening expansion effect is extremely important and urgent. Herein, a versatile strategy combining sol-gel and post-selenization route is proposed for acquiring a series of anion-rich bimetal selenides/sulfoselenides, including a Ni0.75Zn0.25-SSe@C composite with high specific capacity (434.9 mAh g−1 at 0.1 A g−1) and great cyclic stability (271.8 mAh g−1 at 1.0 A g−1 after 300 cycles) as the SIB anode. Particularly, the doping of Zn and S atoms in original anion-rich Ni0.85Se can significantly relieve expansion effect during the long-cycle discharge/charge process, and -the lowered conductivity can be compensated with the surficial carbon coating, resulting in the good performances in SIBs. This new strategy is suitable for the majority of transition metal selenides/sulfoselenides and exhibits an outstanding universality for other multi-component materials even high entropy metal compounds for applications in energy storage and conversion.
•Anion-rich bimetal sulfoselenides were designed to serve as desirable SIB anodes.•The SIB anodes were fabricated through a facile sol-gel route with post-selenylation.•The bimetal sulfoselenide shows weakened expansion effect in sodium storage.•Ni0.75Zn0.25-SSe@C exhibits high capacity and great cyclic stability as SIB anode.•The facile synthesis provides a new project for accessing advanced anode material.
It is a substantial challenge to construct electrocatalysts with high activity, good selectivity, and long‐term stability for electrocatalytic reduction of carbon dioxide to formic acid. Herein, ...bismuth and indium species are innovatively integrated into a uniform heterogeneous spherical structure by a neoteric quasi‐microemulsion method, and a novel C@In2O3@Bi50 core‐shell structure is constructed through a subsequent one‐step phase separation strategy due to melting point difference and Kirkendall effect with the nano‐limiting effect of the carbon structure. This core‐shell C@In2O3@Bi50 catalyst can selectively reduce CO2 to formate with high selectivity (≈90% faradaic efficiency), large partial current density (24.53 mA cm−2 at −1.36 V), and long‐term stability (up to 14.5 h), superior to most of the Bi‐based catalysts. The hybrid Bi/In2O3 interfaces of core‐shell C@In2O3@Bi will stabilize the key intermediate HCOO* and suppress CO poisoning, benefiting the CO2RR selectivity and stability, while the internal cavity of core‐shell structure will improve the reaction kinetics because of the large specific surface area and the enhancement of ion shuttle and electron transfer. Furthermore, the nano‐limited domain effect of outmost carbon prevent active components from oxidation and agglomeration, helpful for stabilizing the catalyst. This work offers valuable insights into core‐shell structure engineering to promote practical CO2 conversion technology.
A phase separation strategy basing on the special thermal shrinkage and cold expansion characteristics of Bi is proposed for one step synthesis of a novel core‐shell C@In2O3@Bi catalyst. Compared with other step‐by‐step methods for heterostructure fabrication, the developed strategy inaugurates a new pathway for designing heterocatalysts with controllable internal structure and excellent catalytic properties.
Modifying the separator of lithium–sulfur batteries (LSBs) is considered to be one of the most effective strategies for relieving the notorious polysulfide shuttle effect. Constructing a stable, ...lightweight, and effective LSB separator is still a big challenge but highly desirable. Herein, a stable and lightweight imide-based covalent organic framework (COF-TpPa) is facilely fabricated on reduced graphene oxide (rGO) through an oxygen-free solvothermal technique. With the directing effect of rGO and changing the side functional group of the monomer, the morphology and the pore tailoring of COF-TpPa can be simultaneously achieved and two-dimensional (2D) COF nanosheets with different functionalities (such as −SO3H and −Cl) are successfully constructed on rGO films. The specific functional groups inside the COF’s pore channels and the narrowed pore size result in efficient absorption and restriction of Li2S n for weakening the “shuttle effect”. Meanwhile, the 2D COF nanosheets on the rGO is a favorable morphology for better exploiting pores inside the COF materials. As a result, the COF–SO3H-modified separator, consisting of rGO and COF-TpPa-SO3H, exhibits a high specific capacity (1163.4 mA h/g at 0.2 C) and a desirable cyclic performance (60.2% retention rate after 1000 cycles at 2.0 C) for LSBs. Our study provides a feasible strategy to rationally design functional COFs and boosts their applications in various energy storage systems.
•A template-assisted sol–gel strategy is proposed for multi-structure engineering of NVP@C cathode material.•Simultaneous realizations of pore constructing, nanosizing and carbon compositing can be ...achieved in one step.•Pore structure of NVP@C can be tuned by adjusting the diameter of PS nanospheres.•A novel mesoporous-macroporous structure can be realized due to the demulsification of PS emulsion.•The mesoporous-macroporous NVP@C exhibits extraordinary rate capability and cycling stability at high rate.
Na3V2(PO4)3 (NVP) is recognized as a promising sodium ion battery (SIB) cathode material due to its high working potential and robust three-dimensional framework. However, the poor intrinsic electronic conductivity and huge volume change during sodium ion insertion/desertion process hinder its further applications, which makes its structure modulations highly desirable. Herein, a facile template-assisted sol–gel strategy is developed to realize multiple structure modulations of NVP@C in one-step. With citric acid as chelating agent and polystyrene (PS) nanospheres as template, the realization of nanosizing NVP particles, hybridizing NVP particle with carbon material and constructing pore structure on NVP@C can be facially achieved. More importantly, the pore structure can be tuned by the diameter of used PS nanospheres. When the diameter of PS nanospheres is down to 70 nm, the corresponding 70-PS NVP possesses a hierarchically mesoporous-macroporous structure due to the demulsification effect, which can shorten the ion diffusion pathway, increase the contact surface area between the electrolyte and active material, improve the diffusion kinetics and buffer the volume change. Benefiting from the above superiority, the sample exhibits an extraordinary rate capability and a prominent cycling stability at high rate (104 mAh g−1 after 5000 cycles at 50C), which surpass most of the recently reported SIB cathode materials. This work opens a facile revenue for boosting the electrochemical performance of electrode materials through characteristic pore construction, nanosizing and integration with carbonaceous materials.
•Physical tests are conducted to explore pipe response to tunnel active face failure.•Pipe deformations reach maximum values at normalized horizontal distance of 0.1 D.•Effect of C/D ratio on pipe ...deformations is less prominent than that of H/D ratio.•Measured results verify calculation chart for estimating pipe tensile strain.
In congested urban areas, earth pressure balance (EPB) shielding is commonly adopted to alleviate tunneling effects on surrounding structures. Tunnel active face instability can cause excessive ground movements, which threaten the serviceability of nearby underground pipelines. However, previous studies mainly focused on tunnel face support pressure and tunnel face failure induced ground movements, while pipeline deformations due to tunnel active face instability are seldomly explored. In this study, a series of physical model tests are designed and conducted to investigate the effects of tunnel cover to diameter ratio (C/D) and normalized horizontal distance (H/D) between tunnel face and existing pipeline on three-dimensional pipeline deformation mechanisms. Tunnel active face instability induces excessive settlements and tensile strains in the existing pipeline when it is located at 0.1 D ∼ 0.3 D in front of tunnel face. By increasing H/D ratio from 0.1 to 0.5, the maximum settlement and tensile strain of the existing pipeline decrease by up to 64.8% and 59.9%, respectively. But the maximum settlement and tensile strain of the pipeline only decrease by up to 14.9% and 7.3%, respectively, as C/D ratio increases from 1.0 to 1.5. Obviously, the effects of C/D ratio on pipeline response are less prominent than that of H/D ratio. The measured results are used to verify calculation charts for directly predicting maximum tensile strains of existing pipelines due to tunnel face active instability induced differential ground movements.
Any tunnel construction inevitably causes differential soil movements, resulting in additional adverse effects on existing pipelines. Although there are many jointed pipelines in practice, previous ...studies commonly simplified existing pipelines as continuous structures. In this study, centrifuge tests were designed and conducted to investigate the influence of joint stiffness on pipeline response due to tunnel excavation. Along the longitudinal pipeline direction, upward and downward pipe-soil relative movements were identified. Because of relatively flexible joints causing a reduction in the pipeline flexural stiffness, tunneling-induced maximum settlement in the jointed pipeline was much larger than that in the continuous pipeline. Tunnel excavation caused bending moment in the continuous pipeline only, while bending moment and joint rotation occurred simultaneously in the jointed pipeline. As a result of joint rotation, tunneling-induced maximum bending strain in the jointed pipeline was less than 42.4% of that in the continuous pipeline. If a jointed pipeline is assumed as a continuous structure, tunneling-induced pipeline settlement is underestimated, while bending strain is grossly overestimated. All the centrifuge test results were adopted to verify the validity of calculation charts for estimating tunneling-induced maximum bending strain and joint rotation in existing pipelines.
Defects, such as unsaturated coordination centers and vacancies, can fundamentally change materials’ inherent properties and growth habits. The development of defect engineering has promoted the ...application of many technologies, but it is still a great challenge to selectively manufacture defect sites in existing material systems. It is shown here that in situ site‐directed tailoring of metal sites in Prussian blue analogs (PBA) can be achieved according to the reducibility differences of different metal atoms, forming naturally nonpreferred unsaturated coordination centers. Meanwhile, the in situ capture of small reducing molecule can realize site‐directed tailoring of crystal facets during crystal growth and results in oriented 1D growth. As an oxygen evolution reaction catalyst, the resulted PBA with the nonpreferred unsaturated coordination centers shows a low overpotential of 239 mV at 10 mA cm−2 in alkali, superior to the original PBAs and the previously reported defective PBA derivatives, which can be ascribed to the unsaturated coordination active center and the unique 1D structure. This work opens up opportunities for producing naturally nonpreferred unsaturated coordination center in nanomaterials for broad applications.
An in situ site‐directed tailoring strategy basing on the reducibility differences of different metal atoms is proposed to achieve naturally nonpreferred unsaturated coordination centers and oriented growth in Prussian blue analogues (PBA). The resulted PBA exhibits excellent OER performances due to the unsaturated coordination active centers and the unique 1D structure.
For the convenience of shoppers and users, there is an increasing demand for construction of basements in close proximity to existing tunnels. To ensure the safety and serviceability of existing ...tunnels, attention has been paid to the basement-tunnel interaction. However, most of previous numerical studies simply assumed the complex interaction as a plane strain problem and often they have overlooked effects of stress path and strain dependency on soil stiffness. Based on a dimensional analysis of the basement-tunnel interaction, three-dimensional numerical parametric study is conducted to explore the influence of aspect ratio (i.e., excavation length (L) along longitudinal tunnel direction / excavation width (B) along transverse tunnel direction) on tunnel responses due to basement excavation. Excavation length (L) varying from 2-10 He (i.e., final excavation depth) while excavation width (B) changing from 1-6 He are considered. Centrifuge test results are used to calibrate and verify soil model and soil parameters adopted. Because of larger inward wall movement and stress relief in a longer excavation, induced heave and transverse tensile strain in the tunnel increase with an increase in aspect ratio. When the aspect ratio and normalised excavation width (B/He) are larger than 2, induced tunnel heave at basement centre can exceed the allowable movement limit (i.e., 15 mm). Moreover, the transverse tensile strain of tunnel is larger than the cracking strain limit of unreinforced concrete (i.e., 150 µε) when the aspect ratio is larger than 1.3. This implies that basements with a smaller aspect ratio impose less adverse effects on existing tunnel.
Lung carcinoma (LC) is a complicated and highly heterogeneous disease with high morbidity and mortality. Both lysyl oxidase-like (LOXL) 2 and 3 act in cancer progression. This work endeavors to ...illustrate the influence of LOXL2/LOXL3 on LC progression and the underlying mechanisms. LOXL family genes and CCAAT enhancer binding protein A (CEBPA) were analyzed in the TCGA database for their expression patterns in LC patients and their correlations with the patient's prognosis. CEBPA, LOXL2, and LOXL3 expression levels were determined in LC cells. Gain- and loss-of-function assays were conducted, followed by assays for cell proliferation, epithelial-mesenchymal transition (EMT), apoptosis, invasion, and migration. The binding of CEBPA or B cell lymphoma protein (BCL)-2 to LOXL2/LOXL3 was verified. The ubiquitination level of BCL-2 and histone acetylation level of LOXL2/LOXL3 in LC cells were analyzed. Database analyses revealed that LC patients had high CEBPA, LOXL2, and LOXL3 expression, which were related to poor prognosis. LC cells also exhibited high CEBPA, LOXL2, and LOXL3 levels. LOXL2/LOXL3 knockdown subdued EMT, proliferation, migration, and invasion while enhancing the apoptosis of LC cells. LOXL2/LOXL3 could bind to CEBPA and BCL-2. LOXL2/LOXL3 knockdown upregulated BCL-2 ubiquitination level and diminished BCL-2 expression in LC cells. CEBPA recruited Tip60 to enhance histone acetylation and transcription of LOXL2/LOXL3 in LC cells. BCL-2 overexpression abolished the impacts of LOXL2/LOXL3 knockdown on LC cells. In conclusion, CEBPA boosts LOXL2 and LOXL3 transcription to facilitate BCL-2 stability by recruiting Tip60 and thus contributes to LC cell growth and metastasis.
•CEBPA, LOXL2, and LOXL3 are highly expressed in LC patients and cells.•LOXL2 or LOXL3 knockdown inhibits LC cell growth in vitro.•LOXL2 or LOXL3 reduces ubiquitination degradation of BCL-2 in LC cells.•CEBPA recruits Tip60 to enhance LOXL2 and LOXL3 transcription in LC cells.•BCL-2 overexpression negates the impacts of LOXL2/LOXL3 knockdown on LC cells.
Metal antimony (Sb) has excellent electrical conductivity and high theoretical capacity of sodium storage based on alloy reaction mechanism and possesses great application potential in sodium ion ...batteries (SIBs). However, serious material fracture and volume expansion during the alloy reaction greatly hinder its commercialization process. To overcome these issues, herein a construction method combining ordered silica template, viscous sol casting and high temperature gel reduction is proposed for fabricating ordered 3D antimony/carbon inverse opal framework (3D Sb/C). With the confining effect of the templates, active antimony nanoparticles are highly dispersed. After the etching process, macroporous inverse opal framework can be constructed. The following repeated oxidation and reduction process on active antimony modifies the surrounding microscopic environment, further forming a huge number of mesopores, and finally resulting in the formation of multi-level porous structure. The acquirement of the 3D Sb/C inverse opals realizes the multiple engineering modulations for SIB application, which is conducive to the exposure of active sites, the buffer of volume expansion, and the path of rapid ion diffusion/electron transfer. Benefiting from these structure advantages, the 3D Sb/C 250 inverse opals exhibit excellent sodium storage capacity (550.4 mAh g−1 at 0.1 A g−1) and cyclic stability (257.9 mAh g−1 after 200 cycles at 1 A g−1).
•3D antimony@carbon inverse opal framework (3D Sb/C) was constructed as SIB anode.•Silica template, sol casting and gel reduction are combined for 3D Sb/C construction.•Active antimony nanoparticles are highly dispersed in carbon inverse opal framework.•The repeated oxidation and reduction process results in multi-level porous structure.•3D Sb/C with the novel porous structure exhibits excellent Na storage performances.
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