scholarly journals Three-Dimensional Cobalt Hydroxide Hollow Cube/Vertical Nanosheets with High Desalination Capacity and Long-Term Performance Stability

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yuecheng Xiong ◽  
Fei Yu ◽  
Stefanie Arnold ◽  
Lei Wang ◽  
Volker Presser ◽  
...  

Faradaic electrode materials have significantly improved the performance of membrane capacitive deionization, which offers an opportunity to produce freshwater from seawater or brackish water in an energy-efficient way. However, Faradaic materials hold the drawbacks of slow desalination rate due to the intrinsic low ion diffusion kinetics and inferior stability arising from the volume expansion during ion intercalation, impeding the engineering application of capacitive deionization. Herein, a pseudocapacitive material with hollow architecture was prepared via template-etching method, namely, cuboid cobalt hydroxide, with fast desalination rate (3.3 mg (NaCl)·g-1 (h-Co(OH)2)·min-1 at 100 mA·g-1) and outstanding stability (90% capacity retention after 100 cycles). The hollow structure enables swift ion transport inside the material and keeps the electrode intact by alleviating the stress induced from volume expansion during the ion capture process, which is corroborated well by in situ electrochemical dilatometry and finite element simulation. Additionally, benefiting from the elimination of unreacted bulk material and vertical cobalt hydroxide nanosheets on the exterior surface, the synthesized material provides a high desalination capacity (117±6 mg (NaCl)·g-1 (h-Co(OH)2) at 30 mA·g-1). This work provides a new strategy, constructing microscale hollow faradic configuration, to further boost the desalination performance of Faradaic materials.

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2134 ◽  
Author(s):  
Li Zeng ◽  
Liping Zhang ◽  
Xingang Liu ◽  
Chuhong Zhang

Sodium-ion batteries (SIBs), as a supplement of lithium-ion batteries (LIBs), are attracting intensive research interest due to their low cost and abundance. Molybdenum disulfide (MoS2) is regarded as a suitable candidates for SIBs electrode materials, which suffer from prominent volume expansion and poor conductivity. In this study, three-dimensional porous graphene composites loaded with MoS2 were prepared via a facile two-step method. The MoS2 nanoflower particles were uniformly dispersed within the layered graphene matrix, and a three-dimensional porous graphene supported MoS2 nanoflower battery (MoS2/3DG) was demonstrated to have superior performance to that of the pristine pure MoS2 nanoflower battery. At a current density of 100 mA/g, the MoS2/3DG delivered a reversible capacity of 420 mAh/g. What is more, it yielded a reversible specific capacity of 310 mAh/g at 2 A/g, showing an excellent rate of 73.8%. The excellent performance of the novel MoS2/3DG composite are attributed to the promoted infiltration of electrolytes and the hindered volume expansion for the porous structure, good conductivity, and robust mechanical properties of graphene.


Author(s):  
Tingting Xia ◽  
Chengfei Xu ◽  
Pengfei Dai ◽  
Xiaoyun Li ◽  
Riming Lin ◽  
...  

Three-dimensional (3D) conductive polymers are promising conductive matrices for electrode materials toward electrochemical energy storage. However, their fragile nature and weak binding forces with active materials could not guarantee long-term...


Author(s):  
Jingxuan Zhao ◽  
Zhibo Zhao ◽  
Yang Sun ◽  
Xiangdong Ma ◽  
Meidan Ye ◽  
...  

Taking into account of time-confusing preparation processing and unsatisfied desalination capacity of carbon nanomaterials, exploring efficient electrode materials remains a great challenge for practical capacitive deionization (CDI) application. In this...


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2273
Author(s):  
Wan-Ying Huang ◽  
Norichika Hashimoto ◽  
Ryuhei Kitai ◽  
Shin-ichiro Suye ◽  
Satoshi Fujita

The occasional malignant transformation of intracranial epidermoid cysts into squamous cell carcinomas remains poorly understood; the development of an in vitro cyst model is urgently needed. For this purpose, we designed a hollow nanofiber sphere, the “nanofiber-mâché ball.” This hollow structure was fabricated by electrospinning nanofiber onto alginate hydrogel beads followed by dissolving the beads. A ball with approximately 230 mm3 inner volume provided a fibrous geometry mimicking the topography of the extracellular matrix. Two ducts located on opposite sides provided a route to exchange nutrients and waste. This resulted in a concentration gradient that induced oriented migration, in which seeded cells adhered randomly to the inner surface, formed a highly oriented structure, and then secreted a dense web of collagen fibrils. Circumferentially aligned fibers on the internal interface between the duct and hollow ball inhibited cells from migrating out of the interior, similar to a fish bottle trap. This structure helped to form an adepithelial layer on the inner surface. The novel nanofiber-mâché technique, using a millimeter-sized hollow fibrous scaffold, is excellently suited to investigating cyst physiology.


2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.


Author(s):  
Jean-Numa Gillet ◽  
Yann Chalopin ◽  
Sebastian Volz

Owing to their thermal insulating properties, superlattices have been extensively studied. A breakthrough in the performance of thermoelectric devices was achieved by using superlattice materials. The problem of those nanostructured materials is that they mainly affect heat transfer in only one direction. In this paper, the concept of canceling heat conduction in the three spatial directions by using atomic-scale three-dimensional (3D) phononic crystals is explored. A period of our atomic-scale 3D phononic crystal is made up of a large number of diamond-like cells of silicon atoms, which form a square supercell. At the center of each supercell, we substitute a smaller number of Si diamond-like cells by other diamond-like cells, which are composed of germanium atoms. This elementary heterostructure is periodically repeated to form a Si/Ge 3D nanostructure. To obtain different atomic configurations of the phononic crystal, the number of Ge diamond-like cells at the center of each supercell can be varied by substitution of Si diamond-like cells. The dispersion curves of those atomic configurations can be computed by lattice dynamics. With a general equation, the thermal conductivity of our atomic-scale 3D phononic crystal can be derived from the dispersion curves. The thermal conductivity can be reduced by at least one order of magnitude in an atomic-scale 3D phononic crystal compared to a bulk material. This reduction is due to the decrease of the phonon group velocities without taking into account that of the phonon average mean free path.


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