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A good bifunctional electrocatalyst can effectively drive water splitting to produce hydrogen gas. In this paper, NiMoO4an nanomaterial was prepared and combined with black phosphorus (BP) in a one-step method. Used as a bifunctional electrocatalyst, the composite demonstrated outstanding electrochemical performance with 162.7 mV and 137.6 mV achieving current densities of 20 mA cm−2 and 10 mA cm−2 for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), respectively. For overall water splitting, the potential was just 1.55 V to achieve 10 mA cm−2, and, especially, the value only rises by0.05 V after 2000 cycles of CV. Here, the one-step synthesis method favors the dispersion of NiMoO4 nanomaterial on the BP surfaces, and facilitates a combination between the nickel molybdate and the BP. Also, the excellent performance of the samples should benefit from the synergistic action between the components. [ABSTRACT FROM AUTHOR]

Nanomedicine has been developed for cancer therapy over several decades, while rapid clearance from blood circulation by reticuloendothelial system (RES) severely limits nanomedicine antitumour efficacy. We design a series of nanogels with distinctive stiffness and investigate how nanogel mechanical properties could be leveraged to overcome RES. Stiff nanogels are injected preferentially to abrogate uptake capacity of macrophages and temporarily block RES, relying on inhibition of clathrin and prolonged liver retention. Afterwards, soft nanogels deliver doxorubicin (DOX) with excellent efficiency, reflected in high tumour accumulation, deep tumour penetration and outstanding antitumour efficacy. In this work, we combine the advantage of stiff nanogels in RES-blockade with the superiority of soft nanogels in drug delivery leads to the optimum tumour inhibition effect, which is defined as mechano-boosting antitumour strategy. Clinical implications of stiffness-dependent RES-blockade are also confirmed by promoting antitumour efficacy of commercialized nanomedicines, such as Doxil and Abraxane. Nanomedicine proofed to be efficient in cancer therapy but rapid clearance from blood circulation by reticuloendothelial system (RES) severely limits the antitumor efficacy. Here, the authors design a series of nanogels with distinctive stiffness and investigate how nanogel mechanical properties could be leveraged to overcome RES. [ABSTRACT FROM AUTHOR]

The development of electrochemical oxygen evolution reaction (OER) catalysts with a simple preparation method and high catalytic efficiency is a primary step to improve energy conversion efficiency. In this work, a series of samples, including black phosphorus (BP) sheets, iron Bolide (Fe2B), Fe2+ doped BP (Fe2+/BP) sheets, and iron Bolide/black phosphorus (Fe2B/BP) sheets were prepared, and their electrochemical properties were investigated. It was found that the composite of amorphous Fe2B/BP sheets showed the best OER performance, which was significantly superior to BP sheets, Fe2B, and Fe2+/BP sheets. It could be seen that Fe2B/BP sheets composite had only a low overpotential of 179 mV at the current density of 10 mA/cm2 in 1 M KOH, and its Tafel slope was 70 mV/dec. In particular, after 1000 cycles, its overpotential only rose by 11 mV at the same current density of 10 mA/cm2, while, after 10 h, its current density only decreased by 0.91 mA/cm2 at the overpotential of 179 mV, showing good stability. This study will mainly explore the performance improvement mechanism in an attempt to synthesize better catalysts for OER. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is the basic reaction to achieve water decomposition and hydrogen production. Here, an OER catalyst material, carbon-coated cobalt pyrophosphate/nickel phosphite (Co2P2O7/Ni(PO3)2@C) composite with sandwich structure, was prepared in vacuum environment by a simple method, which not only simplified the traditional two-step phosphating process but also directly formed carbon layer from homologous carbon. The tests for OER showed that the Co2P2O7/Ni(PO3)2@C composite had lower overpotential and Tafel slope as well as stable catalytic property in alkaline solution. In 1 M KOH, the composite exhibited the overpotential of 279 mV which was lower than that of commercial catalyst at a current density of 10 mA cm−2, and its Tafel slope is 102 mV dec−1. Due to the protection of the carbon layer, the composite exhibited good stability, so that the current density only decreased 3.9% after being cycled for 12 h. This study should help to obtain other stable electrocatalytic materials of transition metal compounds as OER catalysts. [ABSTRACT FROM AUTHOR]

In this paper, α-Fe2O3 was prepared by hydrothermal and chemical precipitation methods, respectively, and its gas sensing properties toward CH4 were systematically studied. The larger specific surface area of the materials provided them potential and considerable gas adsorption abilities. The results of gas-sensing measurements indicated the synthesized α-Fe2O3 materials presented a p-type conductive nature. The sensitivities of the devices based on the different material fabrication methods were measured to be 195% and 214%, respectively, at 370°C for the concentration of 2000 ppm CH4. In addition, the sensing mechanism was discussed and simulated by first-principles calculation. The results revealed the higher surface adsorption energy of α-Fe2O3, which verified the experimental conclusions of our work. Our research suggests that α-Fe2O3 is a promising candidate for CH4 gas sensing in many fields such as mining safety and environmental monitoring. [ABSTRACT FROM AUTHOR]

In this paper, a dual solvent system of glycerol and ethylene glycerol was used to prepare nickel cobalt sulfide with different crystallinities. It was found that the crystallinity and morphology of the product had an important effect on its electrochemical performance. Therefore, the synthesis time was chosen between 1 and 18 h to control the crystallinity. The best sample (GENCS-3) was prepared within 3 hour and had flower-like structures. Its electrochemical tests showed that it had good ion transmission efficiency and excellent specific capacitance (1816 F/g at 1 A/g, 1620 F/g at 10 A/g). Especially, its retention rate could arrive at 89.4% after 1000 cycles under a current density of 5 A/g. The weak crystalline nickel–cobalt sulfide is easy to form porous structure, which can significantly increase capacitance, also maintaining good rate performance. [ABSTRACT FROM AUTHOR]

A convenient chemical vapor transport (CVT) approach to fabricate orthorhombic black phosphorus (BP) single crystal under vacuum is presented. In this system of red phosphorus (RP), tin (Sn), and iodine (I2), the preparation process is recorded in detail and then a relatively optimal temperature program is proposed. The preparation time can be significantly reduced, which takes only 1035 min. And we investigate that the possibility of Sn24P19.3I8 works as the nucleation agent of BP from the theoretical and experimental perspectives. And the theoretical prediction and calculation verify that Sn24P19.3I8 is similar with BP in terms of structure and the existence of Sn24P19.3I8 accorded with the laws of thermodynamics. Additionally, we observe that BP actually grows on Sn24P19.3I8 by high-resolution transmission electron microscopy (HRTEM) for the first time. [ABSTRACT FROM AUTHOR]

The wet ball milling (WBM) method is, for the first time, used for the exfoliation of bulk black phosphorus (BP) to obtain few-layer black phosphorus (FBP). Before that, the rational solid–liquid ratio of raw material is determined to be 1:1 (mg/mL) for the popular ultrasound liquid exfoliation (ULE). Obviously, the high proportion of organic solvent used in ULE will lead to serious environmental pollution. Compared with ULE, the solid/liquid ratio for WBM exfoliation is 100:1 (mg/mL) showing its advantage of less demand for organic solvent. In addition, different types of organic solvents are used to determine the proper organic solvent for WBM exfoliation. Ultraviolet–visible–near-infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and laser particle size analyzer are used to comprehensively characterize the layer numbers, morphology size, and phase structure of FBP yielded by WBM exfoliation. The results show that dimethyl sulfoxide (DMSO) is the suitable organic solvent for BP exfoliation; FBP flakes with 3–5 layers and micron size are obtained by WBM exfoliation. [ABSTRACT FROM AUTHOR]

The preparation process of indium oxide semiconductor nanomaterials was improved gradually, and ultimately, ordered In2O3 fibers with hollow structure were successfully synthesized by electrospinning method with a special-made collector. Compared with the other samples, the ordered sample has the biggest specific surface area, the minimum grain size, and the minimum conduction resistance. So it also has the best gas sensitivity, which is more than twice that of other samples. [ABSTRACT FROM AUTHOR]

Various double-solvent systems, including EG–IPA, glycerol–IPA, EG–methanol and EG–ethanol etc., were used to fabricate nickel–cobalt sulfide (NCS). Their products showed different structure with granular-, hollow sphere-, honeycomb-, irregular sphere-like microstructures and so on. The electrochemical performances of these samples were investigated by CV and GCD measurements. The results indicate that at 1A/g, their specific capacitances are 912, 980, 1464, 1072, 1130, 1108, 1006 and 866 F/g, respectively, among which honeycomb-like structure has the best performance. The best sample also shows excellent charge–discharge performance, that is, it still retains more than 88% of the initial capacity after 2000 cycles. Furthermore, the formation mechanism of the pores in the honeycomb structure was studied in detail. Therefore, a special experiment was designed to reveal the cause of the pore formation. This study is of great significance for the design of transition metal compounds with excellent electrochemical properties. [ABSTRACT FROM AUTHOR]

The composite of polypyrrole and black phosphorus (PPy/BP) has been successfully prepared by the in situ chemical method through the polymerization of pyrrole (Py) on the surface of BP flake. Characterization results show that it present well-dispersed morphological and P–C bonding in PPy/BP. It is evident that the adding of BP exactly brings the changes in morphological and structure. To verify the existence of BP and to obtain the structure relationship between BP and PPy, an auxiliary experiment has been designed and the corresponding XRD and TEM results clearly display that BP is wrapped by PPy. All these morphology and structural characteristics are conductive to the excellent electrochemical performance of PPy/BP. The electrochemical results show that, the capacity of PPy/BP is 515 F/g at 1 A/g, which is ~ 1.7 times (70%) higher than that of PPy and ~ 7.1 times than that of BP. The capacity of PPy/BP reaches stable value within 200 circles, which is faster than that of PPy within 450 circles. The stable value of PPy/BP is still ~ 1.5 times (48%) higher than that of PPy within 1000 circles, presenting better cycling performance. [ABSTRACT FROM AUTHOR]

An electrospinning method was used to synthesize the Co3O4/NiO nanofibers, which then was sulfurized by solvothermal method in order to improve their electrochemical properties. The SEM pictures showed that sulfurized Co3O4/NiO nanofibers were irregular short nano-rods consisting of nanocrystalline particles; the BET tests showed that sulfuration is beneficial to improve the specific surface area of the fibers; the XPS showed that the existence of the valence state: Co2+, Co3+, Ni2+, Ni3+ and S2− in sulfurized sample, which was confirmed by XRD as Co3S4 and Ni0.96S, respectively. Especially, electrochemical tests showed that the sulfurized Co3O4/NiO nanofibers electrode delivers high specific capacity of 156.84 mA h g−1 at 1 A g−1 and 151.07 mA h g−1 at 10 A g−1 and after 1000 cycles, its capacity retention reaches 87.3% at 5 A g−1. The mechanism of improving the electrochemical performance after sulfidation was also discussed in detail. [ABSTRACT FROM AUTHOR]

We generated multilayer black phosphorus (MBP) as a precipitate in centrifugation under 3000 rpm for 25 min, preceded by liquid exfoliation, in which saturated sodium hydroxide (NaOH(s)) was added as an exfoliation auxiliary. The MBP exfoliated with NaOH(s) was characterized by scanning electron microscope, energy dispersive x-ray detector, x-ray diffraction, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Its electrochemical performance was investigated by cyclic voltammetry, charge/discharge and electrochemical impedance spectroscopy. It was found that the appropriate amount of NaOH(s) can make MBP present a ladder-shaped structure or plackets on the layer edge, which may provide more active sites and channels for charge storage to improve its electrochemical performance. The specific capacitance of MBP samples exfoliated with appropriate amounts of NaOH(s) can quickly enter a relatively stable range of 110-90 F/g after the 75th cycle, and finally stabilize at about 90 F/g after thousands of cycles under the current density of 2 A/g, which demonstrates their good stability in the range of long charge/discharge cycles. MBP exhibits double-layer capacitance properties. [ABSTRACT FROM AUTHOR]

In order to improve the electrochemical performance of PANI, we prepared Mn2+ or Mn2O3 doped PANI nanomaterial by interfacial polymerization or in situ polymerization method. The SEM pictures showed that all samples were irregular short nano-rods; the FT-IR and XPS detected the quinone ring and benzene ring information in PANI and especially the XPS showed that manganese existed in the form of Mn2O3 in a sample; the BET tests showed that the Mn doping is beneficial to increase the specific surface area of the doped sample. The electrochemical property of all samples was studied by a three-electrode system in 0.5 mol/L H2SO4. It was found that at the current density of 1 A/g, the maximum specific capacitance of pure PANI was only 378 F/g, which was obviously lower than that of doped samples. Among the doped samples, Mn2O3/PANI had the best performance. Its specific capacitance was 719 F/g, and its capacitance retention was over 90% after 2000 charge-discharge cycles at 10 A/g. Afterwards, the mechanism of improving the electrochemical behavior of nano-PANI by adding manganese was also discussed. [ABSTRACT FROM AUTHOR]

Graphene-cadmium sulfide nanocomposite (G-CdS) was prepared by one pot solvothermal route. Graphite oxide (GO) was well dispersed in dimethyl sulfoxide (DMSO) solution of ions Cd, where DMSO acted as a sulphide source as well as reducing agent, resulting in the formation of G-CdS nanocomposite and simultaneous reduction of GO to graphene nanosheets (GNs). The size of CdS nanoparticles (NPs) in G-CdS was around 10 nm, and the large 2D flexible atom-thin layer of graphene made it easier to control the distribution of CdS NPs. The electrochemical performances of G-CdS nanocomposite were investigated by cyclic voltammetry and charge/discharge techniques. It showed that the G-CdS nanocomposite had a high electrochemical activity, durability, and stability. And the electronic conductivity of nanocomposite was improved and the stability of electrode was enhanced because of the introduction of GNs. [ABSTRACT FROM AUTHOR]

A series of Fe-ions modified BiOBr photocatalysts were synthesized via a facile solvothermal method. The photocatalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transformed infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, N-sorption, photoluminescence spectra, and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of Fe ions modified BiOBr samples were evaluated by the decomposition of methyl orange under visible light irradiation. The results revealed that the introduction of Fe ions greatly improved the photocatalytic performance of BiOBr. The highest activity was obtained by 15 at.%Fe-BiOBr sample. The reasons for the enhanced photocatalytic activities of Fe ions modified BiOBr samples were attributed to strong photoadsorption in the visible light region, high specific surface area, more chemisorbed water and hydroxyl groups and the mediating role of Fe ions in charge transfer. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Bi(Fe Al)O ( x = 0, 0.1, 0.3, 0.5, and 0.7) samples were synthesized by a simple hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformed infrared spectra, N-sorption, and UV-Vis diffuse reflectance spectra, and their photocatalytic activities were evaluated by the degradation of methyl orange under visible-light irradiation. The results reveal that the Al substitution can effectively improve photocatalytic performance, which is attributed to the increase of surface area, the improvement of energy band structure, and the distortion of the Fe-O octahedron in Al-substituted samples. In addition, it is found that the photocatalytic activity to decompose methyl orange under visible-light illumination increases monotonically as x increases from zero to 0.5 in Bi(Fe Al)O and then decreases for x = 0.7, which is believed to be associated with the distribution of Fe ions over the octahedral and tetrahedral sites. [ABSTRACT FROM AUTHOR]

Investigations on the effect of oxidation on titanium-ceramic adhesion were performed. Cast pure titanium was subjected to surface modification by preoxidation and introduction of an intermediate layer of SiO by sol-gel process. Specimens were characterized by TG-DSC, XRD, and SEM/EDS. The adhesion between the titanium and porcelain was evaluated by three-point flexure bond test. Failure of the titanium-porcelain with preoxidation treatment predominantly occurred at the titanium-oxide interface. Preoxidation treatment did not affect the fracture mode of the titanium-ceramic system and did not increase the bonding strength of Ti-porcelain. The SEM results revealed the existence of microcracks on the SiO coating surface oxidized at 800 °C in an air furnace. During the porcelain fusion, minute amounts of oxygen were able to penetrate the cracks and caused localized oxidation of the Ti-substrate. Failure of the titanium-porcelain with SiO coating predominantly occurred at the SiO layer. The SiO coating served as an effective oxygen diffusion barrier and improved the mechanical and chemical bonding between porcelain and titanium. [ABSTRACT FROM AUTHOR]