Black phosphorus (BP), a burgeoning elemental 2D semiconductor, has aroused increasing scientific and technological interest, especially as a channel material in field-effect transistors (FETs). However, the intrinsic instability of BP causes practical concern and the transistor performance must also be improved. Here, the use of metal-ion modification to enhance both the stability and transistor performance of BP sheets is described. Ag spontaneously adsorbed on the BP surface via cation-π interactions passivates the lone-pair electrons of P thereby rendering BP more stable in air. Consequently, the Ag -modified BP FET shows greatly enhanced hole mobility from 796 to 1666 cm V s and ON/OFF ratio from 5.9 × 10 to 2.6 × 10 . The mechanisms pertaining to the enhanced stability and transistor performance are discussed and the strategy can be extended to other metal ions such as Fe , Mg , and Hg . Such stable and high-performance BP transistors are crucial to electronic and optoelectronic devices. The stability and semiconducting properties of BP sheets can be enhanced tremendously by this novel strategy.
2D materials with large specific surface area and robust mechanical properties are appropriate for electrocatalysis. However, the unsatisfactory adsorption energy and limited active sites restrict their commercial application. Herein, a facile and rapid electrochemical strategy enabling synchronous exfoliation and doping is designed to directly synthesize metal‐doped 2D materials from the bulk crystals. By using black phosphorus as a model, various metal doped phosphorene such as BP(Co), BP(Mo), and BP(Ni) is obtained, and a synergistic synthesis mechanism is proposed. Notably, the dopant introduces electronic band transformation, charge redistribution, and state occupation confirmed by density functional theory calculations. Owing to the enhanced electro‐conductivity, abundant metal‐P active sites, and optimized adsorption energy by doping, the BP(metal) exhibits enhanced hydrogen evolution reaction activities and stability in comparison to the bare phosphorene. Particularly, BP(Co) presents highest activity with a potential of 0.294 V at 10 mA cm−2 (the current density is normalized with electrochemical surface area by using a double‐layer capacitance method). This study provides new access to synthesize highly efficient electrocatalysts, and also enriches the structure modulation means for layered 2D materials.
We investigate the effects of topological disorder and wettability on fluid displacement in porous media. A modified disorder index I v is proposed to characterize the disorder of porous media. By changing I v , different displacement patterns (stable displacement and fingering) under the same flow condition and fluid property are obtained. We analytically demonstrate how increase in disorder promotes fingering due to uneven distribution of local capillary pressure. It is shown that the displacement efficiency for different wettability conditions and disorder well correlates with the distribution of local capillary pressure. A power-law relation between fluid-fluid interfacial length and saturation of invading fluid is proposed by taking geometry into account, where the parameters in power-law relation can be predicted by the capillary index, I c , unifying the effects of topological disorder and wettability.
An increasing enthusiasm for research into 2D nanostructures is driven by their exceptional mechanical, chemical, optical, and physical properties that arise from their atomically thin dimension. These properties make 2D nanostructures promising candidates for applications in the next generation of photonic, valleytronic, and (opto-)electronic devices. 2D black phosphorus, for instance, is a novel 2D material with a thickness-tunable bandgap and outstanding properties that have attracted tremendous interest. However, its commercial and industrial applications have been greatly hindered by its poor environmental stability.  Layered transition metal dichalcogenides (TMDs), such as MoS 2 , WS 2 , and MoSe 2 , have been experimentally demonstrated to possess thickness-dependent bandgaps and many other promising physical, chemical, and mechanical properties. However, the majority of these TMDs suffer from relatively low charge-carrier mobilities, rather large Schottky barriers when contacted with metals, complicated fabrication processes and a narrow spectral response mainly in the visible region. [2,3] As a result, even though the first report on the experimental isolation of graphene was 16 years ago,  and researchers worldwide have spent massive time and effort investigating 2D materials, thus far few have been effectively employed in industrial and commercial applications. Recently, layered PtSe 2 , a Group-10 TMD, has been demonstrated to be one of the most promising 2D materials for adoption by industries due to its unprecedented photonic, physical, and chemical properties along with lowtemperature synthesis methods, high charge-carrier mobilities and long-term air stability. [5-11] One of the important industrial advantages of PtSe 2 is the developed synthesis methods, some of which are compatible with modern silicon technologies. The studied methods to synthesize layered PtSe 2 include molecular-beam epitaxy (MBE), [7,12] chemical vapor deposition (CVD), [8,13] thermally assisted conversion (TAC), [14-20] chemical vapor transport (CVT),  plasma-assisted selenization (PAS),  microwave assisted synthesis (MAS),  mechanical exfoliation (ME), [13,23] the wet chemical (WC) method, [24,20] and so on. Both MBE and CVD are typically carried out at high temperature and can result in high-quality PtSe 2 monolayers. In contrast, wafer-scale and thickness-tunable layered PtSe 2 can be obtained using TAC Since the first experimental discovery of graphene 16 years ago, many other 2D layered nanomaterials have been reported. However, the majority of 2D nanostructures suffer from relatively complicated fabrication processes that have bottlenecked their development and their uptake by industry for practical applications. Here, the recent progress in sensing, photonic, and (opto-)electronic applications of PtSe 2 , a 2D layered material that is likely to be used in industries benefiting from its high air-stability and semiconductor-technology-compatible fabrication methods, is reviewed. The advantages and disad...
Depression is a multicausal disorder and has been associated with metabolism regulation and immuno-inflammatory reaction. The anorectic molecule nesfatin-1 has recently been characterized as a potential mood regulator, but its precise effect on depression and the possible mechanisms remain unknown, especially when given peripherally. In the present study, nesfatin-1 was intraperitoneally injected to the rats and the depression-like behavior and activity of the hypothalamic-pituitary-adrenal (HPA) axis were evaluated. The plasma concentrations of nesfatin-1, interleukin 6 (IL-6), and C-reactive protein (CRP); and the hypothalamic expression levels of nesfatin-1, synapsin I, and synaptotagmin I mRNA were evaluated in nesfatin-1 chronically treated rats. The results showed that both acute and chronic administration of nesfatin-1 increased immobility in the forced swimming test (FST), and resulted in the hyperactivity of HPA axis, as indicated by the increase of plasma corticosterone concentration and hypothalamic expression of corticotropin-releasing hormone (CRH) mRNA. Moreover, after chronic nesfatin-1 administration, the rats exhibited decreased activity and exploratory behavior in the open field test (OFT) and increased mRNA expression of synapsin I and synaptotagmin I in the hypothalamus. Furthermore, chronic administration of nesfatin-1 elevated plasma concentrations of IL-6 and CRP, which were positively correlated with despair behavior, plasma corticosterone level, and the hypothalamic mRNA expression of synapsin I and synaptotagmin I. These results indicated that exogenous nesfatin-1 could induce the immune-inflammatory activation, which might be a central hug linking the depression-like behavior and the imbalanced mRNA expression of synaptic vesicle proteins in the hypothalamus.
Fluid-fluid displacement in porous media is a common phenomenon encountered in a wide range of natural and industrial processes, such as water infiltration into soil (
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