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Photocatalytic merging H[sub 2] evolution with benzyl-alcohol (BA) oxidation offers a promising approach to producing H[sub 2] and value-added chemicals due to water photocatalysis with a sluggish kinetic process and gas-mixed H2/O2 gas security concern. Herein, incorporating electron-deficient pyromellitic dianhydride into large π-conjugate polymeric carbon nitride builds an effective in-electric field (IEF). The resultant photocatalyst shows the dependence on the ratio of H2O and BA for H2 and benzaldehyde production, particularly the highest yield rate of H2 (13.87) and benzaldehyde (7.71 mmol h-1 g-1), 69.2% at 400 nm of internal quantum efficiency for H2-evolution, and 2.15% of solar-to-hydrogen efficiency under simulated AM 1.5G irradiation. Mechanism analysis suggests that the strong driving force of effective IEF originates from the cooperating large delocalized π-conjugate and electron-deficient effect, which overwhelms the intrinsic binding energy of charge carrier to enhance its separation and migration efficiency dramatically. Moreover, extended light response and mesoporous channel in photocatalyst improve the absorption edge and tail, the n→π* transition, and mass transport of BA. In situ characterizations revealed that the enhanced H2 production is due to the releasing protons from BA oxidation via carbon-centered radical-mediated. These findings provide a novel strategy and deep understanding of photocatalytic coupling H2 with added-value chemical production. [ABSTRACT FROM AUTHOR]

It is hard to balance high water permeability and good mechanical strength of hydrogel adsorbents. In this study, an enhanced double network hydrogel adsorbent of poly (vinyl alcohol)/poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PVA/PAMPS) was prepared via simple free-radical polymerization. Hydrophilic PAMPS guaranteed high swellability of the adsorbent, which made the sufficient diffusion of metal ions towards adsorbent inside. Meanwhile, the cross-linkage between PVA and PAMPS chains ensured good mechanical strength of the adsorbent. Significantly, the introduction of multifunctional groups (-NHR, -SO3H and -OH) endowed the adsorbent with both chelation and ion exchange function for enhancing heavy metal adsorption. The maximum adsorption capacities of Pb2+ and Cd2+ reached 340 and 155.1 mg/g, respectively. The adsorbent could efficiently remove heavy metals in melting effluent, especially Pb2+ and Cd2+. The removal efficiencies reached 88.1% for Pb2+, 91.4% for Cd2+, 70.4% for Zn2+, 77.4% for Cu2+, 42.5% for Mn2+, 45.1% for Ni2+ and 95.4% for Fe2+ using 2 g/L adsorbent in 2 h. Moreover, the adsorbent showed a good reusability, and the removal efficiencies maintained 94% for Pb2+ and 93% for Cd2+ in the fifth cycle (m/V = 1 g dry gel/L). This work developed a highly practical hydrogel adsorbent for heavy metal removal from wastewater. [ABSTRACT FROM AUTHOR]

Six new metabolites, actinofuranones D-I (compounds 1-6), were isolated together with three known compounds--JBIR-108 (7), E-975 (8), and E-492 (9)--from a fermentation broth of Streptomyces gramineus derived from the lichen Leptogium trichophorum. The structures of the new compounds 1-6 were established using comprehensive NMR spectroscopic data analysis, as well as UV, IR, and MS data. The anti-inflammatory activity of these isolated compounds were evaluated by examining their ability to inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 4, 5, 8, and 9 attenuated the production of NO due to the suppression of the expression of nitric oxide synthase (iNOS) in LPS-induced RAW 264.7 cells. Moreover, 4, 5, 8, and 9 also inhibited LPS-induced release of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). [ABSTRACT FROM AUTHOR]

Graphene is a promising support for nanosized electrocatalysts, however the conventional stacking arrangement of its graphene sheets substantially decreases the catalytic sites on the catalyst. We report here the fabrication of a graphene/Cu electrocatalyst by the simple cyclic voltammetric electrolysis of graphene oxide (GO) and copper ethylenediamine tetraacetate (Cu-EDTA), and find that the electrochemically reduced GO (RGO) and Cu nanoparticles can be sequentially self-assembled into layer-by-layer, 3D sandwich-type, and homogenous architectures as the concentration ratio of Cu- EDTA/GO increases. The 3D sandwich-type RGO/Cu composite (S-RGO/Cu) shows RGO sheets decorated with Cu nanoparticles which stand nearly perpendicular on the electrode, leading to a significant increase in the electrochemically accessible surface area (0.685 cm2) relative to those of the horizontal layer-by-layer RGO/Cu composite (0.147 cm2) and the homogenous RGO/Cu composite (0.265 cm2). Stemming from its high electrochemical surface area, the S-RGO/Cu composite exhibits a high electrocatalytic activity in hydrazine oxidation in terms of current density and overpotential. Mechanistic analysis of the electrode reactions reveals the reaction pathways of hydrazine on RGO/Cu are closely related to the electrochemical surface area of the RGO/Cu electrocatalyst. The correlation between the architectures and their performances in electrocatalysis presented here can guide the design of novel structures with enhanced properties. [ABSTRACT FROM AUTHOR]

Valuable endophytic strains facilitating plants growth and detoxification of heavy metals are required because the application of plant-endophyte symbiotic system is a promising potential technique to improve efficiency of phytoremediation. In this study, endophytic bacterium LRE07 was isolated from cadmium hyperaccumulator Solanum nigrum L. It was identified as Serratia sp. by 16S rRNA sequence analysis. The endophytic bacterium LRE07 was resistant to the toxic effects of heavy metals, solubilized mineral phosphate, and produced indoleacetic acid and siderophore. The heavy metal detoxification was studied in growing LRE07 cells. The strain bound over 65% of cadmium and 35% of zinc in its growing cells from single metal solutions 72 h after inoculation. Besides the high removal efficiencies in single-ion system, an analogous removal phenomenon was also observed in multi-ions system, indicating that the endophyte possesses specific and remarkable heavy metal remediation abilities. [ABSTRACT FROM AUTHOR]

New multifunctional PEG-grafted chitosan copolymers possessing both amino and carboxyl (4) or formyl (5) groups were synthesized by the grafting reaction method between chitosan and heterobifunctional PEG from anionic polymerization of ethylene oxide. Completion of the reactions and characterization of the resulting polymers were demonstrated by 1H NMR, FT-IR and GPC studies. The multifunctional polymers may have potential utility in gene/drug co-delivery or heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Acrylic acid was first electropolymerized on the surface of a gold electrode. Then, polyaniline (PANI) was electrodeposited on the poly(acrylic acid) (PAA) network to give a PANI–PAA composite film. Scanning electron microscopy and electrochemical studies confirmed the formation of PANI–PAA composite which exhibited excellent electroactivity over a wide pH range. The electro-oxidation of ascorbic acid (AA) was studied in detail. The modified electrode exhibits significantly reduced oxidation overpotential. The response towards AA is linear in the range 1.0 μM to 9.3 mM ( R = 0.9997, n = 33) at a potential of 0.1 V (vs. SCE). The sensitivity is 207 μA mM-1 cm-2, and the detection limit is 1.0 μM (S/N = 3). Interferences by uric acid and dopamine are negligible. The electrode thus enables sensitive and selective determination of AA, with a performance superior to many other PANI–based ascorbate sensors. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a simple and sensitive colorimetric detection of cysteine based on the cysteine-mediated color change of ssDNA-stabilized gold nanoparticles (AuNPs). Cysteine is capable of absorbing onto AuNPs surfaces via the strong interaction between its thiol group and gold. ssDNA molecules which stabilize AuNPs against salt-induced aggregation are removed away by cysteine encapsulation on the AuNPs surfaces, resulting in a characteristic color change of AuNPs from red to blue as soon as salt is added. The ratio of absorptions at 640 to 525 nm ( A640/ A525) is linear dependent on the cysteine concentration in the range from 0.1 to 5 μM. Furthermore, amino acids other than cysteine cannot mediate the color change under the identical conditions due to the absence of thiol groups, suggesting the selectivity of the proposed method toward cysteine. The employment of complicated protocols and sophisticated processes such as the preparation of modified AuNPs are successfully avoided in design to realize the simple and low-cost cysteine detection; and the high sensitivity and low cost of the method is favorable for practical applications. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The heterobifunctional polyethylene glycol (PEG) was synthesized by a facile and an efficient synthetic route. A new biodegradable graft copolymer of chitosan-g-PEI-g-PEG-OH possessing a hydroxyl group at the PEG chain end was prepared by the method of grafting reaction between chitosan, polyethylenimine (PEI) and heterobifunctional PEG for constructing amphiphilic copolymers. The amphiphilic and end-functionalized copolymer may have a potential utility in conjugating with targeting moieties for targetable gene or drug delivery. [ABSTRACT FROM AUTHOR]

Flexible all-solid-state supercapacitors (ASSSs) have caught the scientific attention to meet the explosive demand for portable and wearable electronic devices. However, it is difficult for flexible electrode materials to obtain a high areal capacitance at a high mass loading, which limits their commercial applications. In this study, vanadium oxide (V2O5) nanoparticles are introduced into Ti3C2 flakes with the aid of cetyltrimethylammonium bromide (CTAB). The intercalation of V2O5 particles in the interlayer of Ti3C2 establishes a hierarchical structure and facilitates the electrolyte penetration. As a result, the prepared CT-Ti3C2@V2O5 composite electrode achieves a high areal capacitance of 2065 mF cm−2 at 3 mA cm−2 and superior active mass loading (15 mg cm−2). Meanwhile, over 93% capacitance is maintained after 6000 cycles at 18 mA cm−2. The ASSS based on CT-Ti3C2@V2O5 delivers a high areal capacitance of 477 mF cm−2 at 1 mV s−1 and exhibits stable performance at different bending states, which reaches to the advanced level for the ASSSs based on MXenes. [ABSTRACT FROM AUTHOR]