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In this study, the effects of different concentrations of 2,4-dinitrophenol (2,4-DNP) stress on physiological parameters, as well as the uptake and removal of 2,4-DNP in Salix matsudana, were investigated using hydroponic simulation experiments to explore the potential of the use of Salix matsudana in the phytoremediation of wastewater polluted by 2,4-DNP. The results showed that PN (net photosynthetic rate), Tr (transpiration rate), Gs (stomatal conductance), Ls (stomatal limitation value), Fv/Fm (maximal quantum yield of PSII photochemistry), and qp (photochemical quenching coefficient) of Salix matsudana seedlings showed an overall decreasing trend, while Ci (intercellular CO2 concentration) showed an increasing trend with the increase in 2,4-DNP concentration. The net photosynthetic rate and intercellular carbon dioxide concentration showed an opposite trend in the leaves with the increase in 2,4-DNP stress concentration, and the inhibition of net photosynthesis by 2,4-DNP on Salix matsudana seedlings was mainly based on non-stomatal factors. In the 15 d incubation experiment, the values of SOD (superoxide dismutase), POD (peroxidase), and CAT (catalase) indexes were higher at low concentrations of 2,4-DNP stress, and all three enzymes reached their maximum values at 10 mg L−1 of 2,4-DNP and then decreased. Salix matsudana seedlings could tolerate 2,4-DNP stress well, which did not exceed 20 mg L−1. The toxicity of 2,4-DNP solution was significantly reduced after purification by Salix matsudana seedlings. The removal rate of 2,4-DNP was higher than 80% in each treatment group by Salix matsudana purified after 15 days. When the concentration of 2,4-DNP reached 20 mg L−1, the contents of MDA (malonicdialdehyde) were 55.62 mmol g−1, and the values of REC (relative conductivity) and LD (leaf damage) were 63.51% and 59.93%, respectively. The structure and function of the cell membrane in leaves were seriously damaged. With the increase in 2,4-DNP concentration, the removal of 2,4-DNP by Salix matsudana seedlings showed a decreasing trend. When the 2,4-DNP concentration was 5 mg L−1, the highest removal rate of 2,4-DNP by Salix matsudana seedlings was 95.98%, while when the 2,4-DNP concentration was 20 mg L−1, the highest removal rate was 86.76%. It is noted that the suitable, recommended concentration for the phytoremediation of 2,4-DNP contamination by Salix matsudana seedlings is between 8.81 and 13.78 mg L−1.

Exploring the structure and composition of catalysts to realize fast electron transfer in electrochemical reaction is a challenging part for the development of highly efficient electrocatalysts. Herein, nitrogen-doped carbon nanotube with encapsulated cobalt nanoparticles is synthesized via co-pyrolysis of zeolitic imidazolate framework and assisted nitrogen/carbon precursors with high N/C ratio. These precursor-dependent materials are served as catalysts for determination of hydrogen peroxide (H2O2) and oxygen reduction reaction (ORR). Electrochemical measurement results suggest a strong relationship between N-doped types and electrochemical performance. The as-proposed ZU catalyst (urea as N-rich precursor) exhibits optimal electrocatalytic performance towards ORR and H2O2 detection. Furthermore, ZU also can be a potential cathode candidate for direct borohydride fuel cell (DBFC). The synthesis strategy offers a new clue in constructing effective non-noble-metal catalysts for electrochemical applications. [ABSTRACT FROM AUTHOR]

The formation of a vancomycin hydrogel by hydrophobic interaction and hydrogen bonding self-assembly in water is described. A new kind of small molecular hydrogelators based on an important member of antibiotics is demonstrated and it is concluded that such hydrogels provide a new kind of biomaterial.

Surface texture of a nanostructured electrode plays a key role in electrochemical application. Here we reported the CuO microspheres with different nanostructures covered nickel foam skeleton obtained via controllable synthesis strategy with the assistance of urea, and their performance in nonenzymatic glucose sensor and supercapacitor applications. The suitable nanostructures are conductive to pave the way to provide sufficient interfacial contact between electrode and electrolyte. The twin CuO microspheres composed of ultrathin nanoslices being ~6 nm in thickness and presented well-defined mesoporous nanostructure. The glucose sensor based on the twin CuO nanoslice sphere/Ni foam composite electrode had two wide linear response ranges with ultrahigh sensitivity of 1.864×104 μA mM-1 cm-2 from 1 μM to 100 μM and 160.6 μA mM-1 cm-2 from 1 mM to 8 mM, and a remarkable lower detection limit less than 60 nM (S/N = 3), with a response time as fast as 3 s. Besides, we demonstrated that the electrode was capable of delivering superior areal specific capacitance of 425 mF cm-2 at current density of 0.5 mA cm-2 with excellent cycling stability. Moreover, the investigation of the effects of CuO surface morphology on the interfacial processes can be extended to a wide range of electrochemical systems. [ABSTRACT FROM AUTHOR]

Taking bromophenol blue as pollutant model, the role of sulfate electrolytes during the anodic oxidations was investigated in a wide range of concentrations (0,1-500 mM). Trials were performed with an electrochemical cell containing boron-doped diamond anode and stainless steel cathode. The impact of sulfate concentration on the degradation performance was assessed by comparing the color removal efficiencies at various time intervals. The results revealed a significant and peculiar influence of this parameter on the degradation efficiency. Thus, we emphasize the importance of selection of operating levels in electrolytic oxidations, especially when certain activators (from the cathode) may be formed in the treated solutions. [ABSTRACT FROM AUTHOR]

B/N-codoped TiO2 hollow spheres (B/N-THs) were synthesized by facile one-pot hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms, UV-vis diffuse reflectance spectrum (DRS) and X-ray photoelectron spectroscopy (XPS). The B/N-THs have large surface areas (up to 172.1 m² g-1). The photocatalytic activities of as-prepared THs were evaluated by degradation of Reactive Brilliant Red dye X-3B solution under visible light irradiation. The results showed that B/N-THs exhibited the highest photocatalytic activity due to their high surface area and synergetic effect of B/N-codoped. A photocurrent-time spectrum was examined by anodic photocurrent response to characterize the electron-transferring efficiency in the process of photocatalysis reaction. [ABSTRACT FROM AUTHOR]

Two types of independent titania nanotube arrays with the separated tube wall structure have been fabricated by a controlled anodization process and used for photoelectrocatalysis (PEC) applications. The photocatalysis degradation efficiency of the organic pollutant is improved from 6.0 to 9.2% through increasing tube length and inter-tube space. The PEC degradation efficiency is 20.4% at an applied potential of 2.885 V for titania long nanotube array. An electro-Fenton-assisted PEC reaction system has been developed using titania long nanotube array and an iron sheet as two anodes in a parallel connection and a multiporous carbon as one cathode. The current distribution among three functional electrodes is conducted to optimize titania PEC reaction and electro-Fenton reaction. Accordingly, the degradation efficiency is improved from 20.4% in PEC to 60.2% in electro-Fenton-assisted PEC, and the mineralization efficiency is also improved from 8.1 to 37.4%. The corresponding reaction rate constant of 5.19 × 10−3 min−1 is even higher than that of 3.98 × 10−3 min−1 for the sum of individual oxidation reactions of titania PEC, electro-Fenton, and anodic electrolysis. [ABSTRACT FROM AUTHOR]

Three kinds of magnetic nanoparticle, tetraheptylammonium capped nanoparticles ofFe3O4,Fe2O3 and Ni have been synthesized, and the synergistic effect of these nanoparticles onthe drug accumulation of the anticancer drug daunorubicin in leukaemia cellshas been explored. Our observations indicate that the enhancement effect ofFe3O4 nanoparticles is muchstronger than that of Fe2O3 and Ni nanoparticles, suggesting that nanoparticle surface chemistry and size as well asthe unique properties of the magnetic nanoparticles themselves may contributeto the synergistic enhanced effect of the drug uptake of targeted cancer cells. [ABSTRACT FROM AUTHOR]

Composite nanocrystal materials CdS/PW[sub12]O[sub40]&sup3-; with an ordered structure formed by CdS clusters surrounded with dispersed PW[sub12]O[sub40]&sup3-; anions were synthesized. The material has of a long period about 6.6 nm in agreement with the size sum of individual CdS cluster and PW[sub12]O[sub40]&sup3-; anion. [ABSTRACT FROM AUTHOR]

Composite nanocrystal materials CdS/PW[sub12]O[sub40]&sup3-; with an ordered structure formed by CdS clusters surrounded with dispersed PW[sub12]O[sub40]&sup3-; anions were synthesized. The material has of a long period about 6.6 nm in agreement with the size sum of individual CdS cluster and PW[sub12]O[sub40]&sup3-; anion. [ABSTRACT FROM AUTHOR]

A novel magnetically separable photocatalyst (titania-coated carbon encapsulated magnetite: TCCEF) was prepared. The prepared composite photocatalyst was characterized with an x-ray diffractometer (XRD), a transmission electron microscope (TEM), a Fourier transform infrared spectrometer (FT-IR) and a vibrating sample magnetometer (VSM). The photocatalytic activity of the samples was determined by degrading model contaminated water, a phenol aqueous solution. The results were compared with single-phase titania (pure titania and Degussa P25) and Fe3O4/TiO2, and enhanced photocatalytic activity was obtained. It is suggested that the enhanced photocatalytic activity is ascribed to two major factors. First, the encapsulation of magnetite into the carbon layer may inhibit the direct electrical contact of titania and magnetite, hence preventing the photodissolution of the iron oxide phase. Second, the enhanced hydroxyl groups on TCCEF may inhibit the recombination of electron-hole pairs. On the other hand, the magnetic photocatalyst can be easily recovered from a slurry with the application of an external magnetic field. [ABSTRACT FROM AUTHOR]

In the present paper, the fractal properties of boron-doped diamond (BDD), mixed metal oxide (MMO) and activated carbon fiber (ACF) electrode have been studied by SEM imaging at different scales. Three materials are self-similar with mean fractal dimension in the range of 2.6-2.8, confirming that they all exhibit very rough surfaces. Specifically, it is found that MMO film is more uniform in terms of fractal structure than BDD and ACF. As a result, the intriguing characteristics make these electrodes as ideal candidates for high-performance decontamination processes. [ABSTRACT FROM AUTHOR]

This work shows results obtained in the electrochemical degradation of 50mgdm-3 Acid Orange II dye in the presence of different supporting electrolytes (sulfate, chloride, and their mixture of different proportion). Experiments have been performed with a batch recirculation cell containing boron-doped diamond anode and Pt cathode. The effect of operating parameters, such as treatment time (20-40min), flow rate (400-600mlmin-1), applied current density (1.29-2.58mAcm-2) and total concentration of supporting electrolytes (1.0-5.0mM), on treatment performance is assessed implementing a factorial experimental design. The results obtained, demonstrate that chlorides play interesting and important roles during the electrolytic oxidations. Additionally, the evidences from UV-vis spectra are used to better clarify the different roles of operating variables recorded. [ABSTRACT FROM AUTHOR]