Recently, 3D graphene‐based macrostructures (3D GBMs) have gained increased attention due to their immense application potential in water treatment. The unique structural features (e.g., large ...surface area and physically interconnected porous network) as well as fascinating properties (e.g., high electrical conductivity, excellent chemical/thermal stability, ultralightness, and high solar‐to‐thermal conversion efficiency) render 3D GBMs as promising materials for water purification through adsorption, capacitive deionization, and solar distillation. Moreover, 3D GBMs can serve as scaffolds to immobilize powder nanomaterials to build monolithic adsorbents and photo‐/electrocatalysts, which significantly broadens their potential applications in water treatment. Here, recent advances in their synthesis and application toward water purification are highlighted. Remaining challenges and future perspectives are elaborated to highlight future research directions.
The assembly of individual graphene nanosheets into 3D macrostructures provides an effective way to resolve the challenges met in their practical application. The recent advances in 3D graphene‐based macrostructures for water treatment are highlighted. A perspective on outstanding problems, future opportunities, and challenges is also provided.
Display omitted
•CuO@MnAl NSs have been fabricated by co-precipitation and hydrothermal approach.•MnAl layered doubled hydroxide can be used to wrap n-type CuO nanoparticles.•MnAl layered doubled ...hydroxide serves as p-type semiconductive material.•CuO@MnAl NSs electrode demonstrates excellent electrochemical performance towards the nonenzymatic sensing of H2O2.•Real-time monitoring of H2O2 from blood serum, urine and secreted by live tumorigenic and normal cells.
Structurally integrated metal oxide intercalated layered double hydroxide (LDH) nanospheres (NSs) hybrid material has been of considerable current interest because of their unique structure and synergistic combination of multi- functional properties of nanocomposites. In this work, we report a new type of MnAl LDH wrapped CuO (CuO@MnAl LDHs) NSs by anchoring CuO nanoparticles (NPs) with MnAl LDHs via a facile co-precipitation and hydrothermal approach, and explore its practical application as high-efficient electrocatalyst towards H2O2 reduction for biological application. Our findings demonstrate that the integration of n-type spinel of CuO and p-type semiconductive channels of MnAl LDHs can accelerate electron transfer at breakdown voltage of p-n junction. Owing to the synergistic effect of the high surface area of CuO NPs, superb intercalation features of semiconductive MnAl LDHs for encapsulating NSs, and their intrinsic p-n junction characteristics, CuO@MnAl NSs have exhibited excellent electrocatalytic activity towards the reduction of H2O2. When implemented in electrochemical sensor system, the CuO@MnAl NSs modified electrode displays high nonenzymatic sensing performances towards H2O2 including a broad linear range 6μM–22mM, a low detection limit of 0.126μM, good selectivity and long term stability, which can be exploited for in vitro detection of H2O2 in human serum and urine samples, as well as real-time tracking H2O2 secreted from different human live cells.
•We propose an algorithm to compute the minmax regret.•We solve the minmax 1-facility location problem on uncertain path network.•Our algorithm improves the previous work.•We discover new ...observations on the problem.
Let P be an undirected path graph of n vertices. Each edge of P has a positive length and a constant capacity. Every vertex has a nonnegative supply, which is an unknown value but is known to be in a given interval. The goal is to find a point on P to build a facility and move all vertex supplies to the facility such that the maximum regret is minimized. The previous best algorithm solves the problem in O(nlog2n) time and O(nlogn) space. In this paper, we present an O(nlogn) time and O(n) space algorithm, and our approach is based on new observations and algorithmic techniques.
Developing efficient and inexpensive electrocatalysts for the hydrogen evolution reaction (HER) is critical to the commercial viability of electrochemical clean energy technologies. Transition metal ...phosphides (TMPs), with the merits of abundant reserves, unique structure, tunable composition, and high electronic conductivity, are recognized as attractive HER catalytic materials. Nevertheless, the HER electrocatalytic activity of TMPs is still limited by various thorough issues and inherent performance bottlenecks. In this review, these issues are carefully sorted, and the corresponding reasonable explanations and solutions are elucidated on the basis of the HER catalytic activity origins of TMPs. Subsequently, highly targeted multiscale strategies to improve the HER performance of TMPs are comprehensively presented. Additionally, critical scientific issues for constructing high‐efficiency TMP‐based electrocatalysts are proposed. Finally, the HER reaction process, catalytic mechanism research, TMP‐based catalyst construction, and their application expansion are mentioned as challenges and future directions for this research field. Expectedly, this review offers professional and targeted guidelines for the rational design and practical application of TMP‐based HER catalysts.
In this review, the electrocatalytic activity origins of transition metal phosphides (TMPs) for hydrogen evolution reaction (HER) are insightfully elucidated. Accordingly, the highly targeted multiscale strategies to further improve the HER catalytic performance of TMPs are also comprehensively summarized, aiming to offer more professional and targeted guidelines for the rational design and practical application of TMPs‐based HER electrocatalysts.
•A novel modular liquid-cooled BTMS for cylindrical lithium ion cells is designed.•The cell physical parameters as the simulation input are obtained by experiments.•There is a limit to improve the ...cooling effect by increasing coolant flow rate.•Parallel cooling can effectively improve thermal equilibrium behavior.•The flow direction layout III demonstrates the optimum cooling effectiveness.
Effective battery thermal management system (BTMS) is significant for electric vehicle to maintain the properties and life-time of the battery packs. As an effective cooling method, liquid cooling appears in many publications, but the study of cooling performance based on practical modular structure is relatively scarce. This paper has proposed a novel modular liquid-cooled system for batteries and carried out the numerical simulation and experiment to study the effect of coolant flow rate and cooling mode (Serial cooling and parallel cooling) on the thermal behavior of the battery module. The results show that increasing the coolant flow rate can significantly lower the maximum temperature and improve the temperature uniformity of the battery module in a certain flow range; when the flow rate increases to a certain value, increasing the cooling water flow rate has no obvious effect on improving cooling effect. Compared with serial cooling, parallel cooling can evidently promote the temperature uniformity of the battery module. Furthermore, the designed flow direction layout III can control Tmax to 35.74 °C with ΔT as 4.17 °C. The modular structure can be suitable for industrial batch production and group the batteries flexibly to meet the actual demand. The present study can provide a new approach for the modular design of liquid-cooled battery thermal management system.
Interconnected macroporous poly(acrylic acid) (PAA) hydrogels are prepared via oil-in-water (o/w) Pickering high internal phase emulsion (HIPE) templates stabilized by graphene oxide (GO). The ...amphiphilicity of GO is adjusted by slight modification with cetyltrimethylammonium bromide (CTAB). The morphology of macroporous PAA is observed by a field-emission scanning electron microscope (FE-SEM). The gas permeability is characterized to evaluate the interconnectivity of polymer foams. The pore and pore throat size can be tailored by varying the wettability and concentration of GO. The selective adsorption toward dyes of PAA hydrogels is proved. Macroporous PAA hydrogels with an open-cell structure show enhanced adsorption behavior of both methylene blue (MB) and copper(II) ions.
Dopamine is a brain neurotransmitter involved in the pathology of schizophrenia. The dopamine hypothesis states that, in schizophrenia, dopaminergic signal transduction is hyperactive. The ...cAMP-response element binding protein (CREB) is an intracellular protein that regulates the expression of genes that are important in dopaminergic neurons. Dopamine affects the phosphorylation of CREB via G protein-coupled receptors. Neurotrophins, such as brain derived growth factor (BDNF), are critical regulators during neurodevelopment and synaptic plasticity. The CREB is one of the major regulators of neurotrophin responses since phosphorylated CREB binds to a specific sequence in the promoter of BDNF and regulates its transcription. Moreover, susceptibility genes associated with schizophrenia also target and stimulate the activity of CREB. Abnormalities of CREB expression is observed in the brain of individuals suffering from schizophrenia, and two variants (-933T to C and -413G to A) were found only in schizophrenic patients. The CREB was also involved in the therapy of animal models of schizophrenia. Collectively, these findings suggest a link between CREB and the pathophysiology of schizophrenia. This review provides an overview of CREB structure, expression, and biological functions in the brain and its interaction with dopamine signaling, neurotrophins, and susceptibility genes for schizophrenia. Animal models in which CREB function is modulated, by either overexpression of the protein or knocked down through gene deletion/mutation, implicating CREB in schizophrenia and antipsychotic drugs efficacy are also discussed. Targeting research and drug development on CREB could potentially accelerate the development of novel medications against schizophrenia.
Flexible dielectric polymeric films are highly desirable materials with potential applications in power-conditioning equipment and pulsed-plasma thrusters due to their high dielectric constant, low ...dielectric loss, and fast energy uptake and delivery. In this work, 1–3 type nanocomposites combining BaTiO3 nanotubes (BT NTs) and poly(vinylidene fluoride) (PVDF) were prepared by a solution cast method. The BT NTs were synthesized by facile coaxial electrospinning and were coated with a dense and robust dopamine layer, which effectively improved the filler-matrix distributional homogeneity and compatibility. The 10.8 vol% BT-DA NTs/PVDF nanocomposites possessed an excellent dielectric constant of 47.05, which is approximately 569% greater that of the pristine PVDF (8.26) and 150%–350% higher than that of the other PVDF nanocomposites loaded with similar ceramic filler contents, e.g., nanoparticles, nanowires, and nanofibers. The highest energy density of 7.03 J cm−3 at a relatively low field of 330 MV m-1 was obtained via small loaded of the fillers, which is approximately 625% greater than for biaxially oriented polypropylenes (BOPP) (1.2 J cm−3 at the field of 640 MV m−1). The approach employed in this study may be further applied to the fabrication of similar polymeric nanocomposites for next-generation electronic components.
Herein, an example of Cu‐doped few‐layer ZnIn2S4 nanosheets is used to reveal the origin of optimum and excess doping for photocatalysts at atomic level. Results show that the metal‐S4 coordination ...maintains well with 0.5 wt% Cu substituted Zn atoms in the lattice. The introduced Cu atoms bring electronic acceptor states close to the valence band (VB) maximum and thus ensures higher charge density and efficient carrier transport, resulting in an optimum hydrogen evolution rate of 26.2 mmol h−1 g−1 and an apparent quantum efficiency of 4.76% at 420 nm. However, a distorted atomic structure and largely upshift of VB maximum with Cu‐S3.6 coordination are found with excess doping concentration (3.6 wt%). These bring the heavy charge recombination and consequentially dramatic reduced activity. This work provides a new insight into elemental doping study and takes an important step toward the development of ultrathin 2D photocatalysts.
Few‐layer ZnIn2S4 nanosheets with tunable copper doping are used to disclose the origin of optimum and excess doping for photocatalysis at atomic level. Experimental and theoretical evidence reveal that optimal and excess doping is derived from the different local coordination configuration of dopants, extent of distortion, and the change of electronic structure.
Flexible electrostatic capacitors are potentially applicable in modern electrical and electric power systems. In this study, flexible nanocomposites containing newly structured one-dimensional (1D) ...BaTiO3@Al2O3 nanofibers (BT@AO NFs) and the ferroelectric polymer poly(vinylidene fluoride) (PVDF) matrix were prepared and systematically studied. The 1D BT@AO NFs, where BaTiO3 nanoparticles (BT NPs) were embedded and homogeneously dispersed into the AO nanofibers, were successfully synthesized via an improved electrospinning technique. The additional AO layer, which has moderating dielectric constant, was introduced between BT NPs and PVDF matrixes. To improve the compatibility and distributional homogeneity of the nanofiller/matrix, dopamine was coated onto the nanofiller. The results show that the energy density due to high dielectric polarization is about 10.58 J cm–3 at 420 MV m–1 and the fast charge–discharge time is 0.126 μs of 3.6 vol % BT@AO-DA NFs/PVDF nanocomposite. A finite element simulation of the electric-field and electric current density distribution revealed that the novel-structured 1D BT@AO-DA NFs significantly improved the dielectric performance of the nanocomposites. The large extractable energy density and high dielectric breakdown strength suggest the potential applications of the BT@AO-DA NFs/PVDF nanocomposite films in electrostatic capacitors and embedded devices.
PDF
