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Biogenic nanoparticles are considered effective alternatives to chemical pesticides for the management of pathogenic plant diseases. This study was focused on the synthesis of stable silver nanoparticles (AgNPs) to control challenging plant pathogenic bacteria in vitro and in planta. We synthesized AgNPs by reacting different proportions of silver nitrate and aqueous extract of Hedera nepalensis. The physicochemical properties of the synthesized AgNPs were determined by using various physical techniques. The TEM analysis revealed the AgNPs less than 50 nm in size and spherical shaped. For antibacterial assays, different concentrations (1000–15.62 µg/mL, 2-fold dilutions) of the extract-free AgNPs (Ef-AgNPs) or extract-mixed AgNPs (Em-AgNPs), and fruit extracts (FE) were used against plant pathogenic bacteria Erwinia carotovora subsp. carotovora, Erwinia carotovora subsp. atroseptica, and Ralstonia solanacearum. In the in vitro assays, we found significant inhibition of both bacterial species in response to maximum concentrations of AgNPs. Overall, Ef-AgNPs exhibited a higher percent inhibition of bacterial pathogens. In potato tubers assay, complete inhibition of Erwinia carotovora was observed, except for the lowest AgNPs concentration of 15.62 µg/mL. Similarly, exposure of tomato plants to Ralstonia solanacearum suspensions (OD600 = 0.2) in the soil-drenching experiment and post-exposure treatment with 1000 µg/mL and 125 µg/mL of AgNPs resulted in disease inhibition. This study provides the basis that biogenic nanoparticles prepared from Hedera nepalensis are one of the best substitutes to synthetic pesticide, having displayed better results to control the growth of phytopathogenic microbes. However, field studies need to be conducted in a controlled environment to scale up the current work and find out the efficacy of nanoparticles on a larger scale. [ABSTRACT FROM AUTHOR]

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Use of wastewater for growing vegetables has become a common practice around big cities. Wastewater contains organic material and inorganic elements essential for plant growth but also contain heavy metals which may be lethal for animals and humans if their concentration increases than permissible limit. To monitor this situation, a survey was conducted to ascertain the addition of heavy metals into agricultural fields through wastewater irrigation and their translocation in to the edible parts of the vegetables. For this purpose, during year 2009-10, 25 sewage water, 76 soil, 40 leaf and 30 vegetable samples (tomato, spinach, carrot and cauliflower) were taken from peri-urban area of Lahore district. These samples were analyzed for Zn, Cu, Fe, Mn, Pb, Cd and Ni contents. The analysis showed that in wastewater concentration of Cu (100 %), Mn (72 %), Ni (32 %) and Cd (44%) were higher than the safe limits while Zn, Fe and Pb concentration was below permissible limits. In soil DTPA extractable concentration of Zn, Cu, Fe, Mn, Pb, Ni and Cd was in safe limit and ranged between 1.30-8.02, 1.06 -5.42, 8.60-35.03, 8.7-30.07, 2.11-30.86, 0.28-1.76 and 0.05-0.52 mg kg-1 respectively. In vegetable, 100 % leaf and fruit samples were contaminated and accumulation of heavy metals was higher than the WHO/FAO recommended permissible limits.

Two-dimensional graphitic carbon nitrides (2D g-C3N4) are promising photocatalysts for water splitting to hydrogen due to their non-toxicity and high stability. However, the bulk g-C3N4 has some intrinsic drawbacks, such as rapid electron–hole recombination and low charge-carrier mobility, resulting in poor photocatalytic activity. Here, 2,4-diamine-6-phenyl-1,3,5-triazine was employed as a precursor to regulating the assembly of melamine and cyanuric acid in water. The resulting g-C3N4 not only improved the visible light absorption and electron–hole separation but also provided more catalytic sites for enhanced photocatalytic hydrogen evolution. The modified g-C3N4 (CNP10-H) showed a hydrogen-releasing rate of 2184 μmol·g−1·h−1, much higher than the bulk g-C3N4. [ABSTRACT FROM AUTHOR]

[Display omitted] • One step polyol-solvothermal methodology designed for creating the 0D, 1D, 2D and 3D silver. • This methodology eliminated the old traditional factors (stirring/injection speed, etc). • With the produced gases during reaction can directly control the dimensional morphologies. The common polyol techniques were used for the synthesis of solo metallic morphology. Here we reported the single-step polyol-solvothermal strategy for the synthesis of zero, one, two, and three-dimension silver structure by simply switching the reaction pressure with the help of silver amount and halide ions. Silver seeds in the presence of Cl- ion, at 74.1 mmHg grow in [1 1 1] and at 97.4 mmHg grow in [1 1 0] direction for the formation of 0D-Ag and 1D-Ag respectively, by protecting (1 0 0) facet. Extra halide (Br-) presence at 93.2 mmHg imposes the seeds to grow [1 1 0], [1 0 0] direction for 2D-Ag, while at 97.4 mmHg grow only in [1 0 0] direction for 3D-Ag, due to etching and formation of single crystal seeds. This closed reaction system doesn't need any kind of oxygen scavengers, inert gases, nor need to tune injection speed and stirring speed. This switching strategy can be implemented for the synthesis of other metallic morphologies. [ABSTRACT FROM AUTHOR]

Transition metal@nitrogen–carbon (M@NC) catalysts are greatly desired for zinc–air batteries due to the promising oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) properties. Herein, a uniformly distributed Co@NC catalyst derived from metal–organic frameworks is developed. The CoNx species and Co nanoparticles encapsulated in carbon networks promote ORR and OER kinetics synergistically. Moreover, a novel structure is designed for exposing active sites, which consists of 3D macroporous skeleton embedded in carbon fiber paper. It is revealed that the outstanding ORR and OER properties attribute to the sufficient active area obtained from porous structure and ultra‐thickness (280 µm). Besides, interconnected macropores provide abundant channels for mass transport. The liquid ZABs assembled using 3DOMCo@NC‐1‐090 displays outstanding performances. [ABSTRACT FROM AUTHOR]

A novel graphene nanoplatelets (GNP) bridge between two semiconductors (AgBr and graphitic carbon nitride) was created to boost photoelectrochemical performance. The heterojunction created makes the whole system a Z-scheme catalyst. For the construction of this catalyst, the syringe pump methodology was adopted and different analytical techniques were used for the confirmation of structure and morphology. High angle annular dark field (HAADF), dark field (DF), DF-4 and DF-2 techniques, using Z-contrast phenomena, confirmed the heterostructure (ABGCN) and its composition. The constructed structure showed an enhanced photoelectrochemical and catalytic property against 'acute toxicity category-III (MM)' and 'category-IV (tetracycline hydrochloride (TH))' organic pollutants. The constructed catalyst degraded the MM in 57 min and the TH in 35 min with degradation rates of 0.01489 min−1 and 0.02387 min−1, respectively, due to the accumulation of photogenerated electrons on the conduction band (CB) of g-C3N4 and photogenerated holes on the valence band (VB) of AgBr by the transformation of charges through the graphene bridge. An ion trapping study also revealed that ·O2 and h+ were the active species which actively participated in the photocatalytic reaction. [ABSTRACT FROM AUTHOR]

The vacuum tube method has been used for the construction of nondestructive and physically stable graphitic carbon nitride/graphene nanoplatelet composites and their photocatalytic behavior studied by measuring different photoactivities, such as photocurrent, photoluminescence, and the photodegradation of tetracycline hydrochloride under visible‐light irradiation. The formation of a heterojunction was confirmed by XRD, TEM, SEM, FTIR, XPS, and Raman spectroscopy. The results of this research indicate that the vacuum tube method is a facile, economic, and environmentally friendly approach to the preparation of composites. An ion‐trapping experiment indicated that, under visible light, the most effective photocatalyst generated the superoxide radical (O2·–) and holes (h+) to achieve the complete degradation of tetracycline hydrochloride. [ABSTRACT FROM AUTHOR]

A novel metal free, graphitic carbon nitride self-type heterojunction was successfully created. A self-type heterojunction between two different kind of graphitic carbon nitride with a promote charge separation ability, one was prepared by solvothermal using the dicyandiamide as precursor and other was prepared by direct heating from melamine precursor. This synthesis process is facile, economical and environment friendly. The confirmation of synthesis and heterojunction formation was based on the X-ray-Diffraction, Transmission electron microscopy, Scanning electron microscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy and photocurrent. The potential difference in heterojunction between different types of g-C 3 N 4 is the main acting power for the proficient separation and transformation of photo generated charges. Degradation results indicated that, the removal of antibiotic from effluents, graphitic carbon nitride heterojunction (GCN-DM) pointedly enhanced the visible light catalytic activity over solo graphitic carbon nitride (GCN-D, GCN-M). The improved photocatalytic behaviour of heterojunction may be due to charge separation and transfer ability with prolong lifetime of photo-generated charge carrier. The results also indicated that the optical and surface area properties also play a significance role in enhancement of photo-catalytical ability of target photo-catalyst. [ABSTRACT FROM AUTHOR]

This study focused on the fabrication of a peculiar 3D/2D ZnIn 2 S 4 /oxygen-doped graphitic carbon nitride (ZnIn 2 S 4 /SO-GCN) through a simple hydrothermal method. The flower-like morphology of hexagonal ZnIn 2 S 4 disperse on the SO-GCN nanosheets are evidenced by XRD, scanning and transmission electron microscopy. The as-synthesized nanocomposites were intensively applied for the visible light photocatalytic removal of aqueous phase 2,4-D. The heterojunction creation and the well-developed combined interface between ZnIn 2 S 4 and SO-GCN significantly increases its photogenerated charge separation capability. The photo-degradation mechanism disclose that the heterojunction has improved catalytic degradation activity, due to efficient transferring of photogenerated electron-holes pairs. Under visible-light irradiation, these nanocomposites showed 3–5 times higher degradation rate of 2,4-D (i.e. 0.0112/min, by 30%-ZnIn 2 S 4 /SO-GCN), as compared to solo ZnIn 2 S 4 and SO-GCN, attributed to the composite's synergistic effect in unique 3D/2D heterojunction, that accelerates the electron-hole separation. The h+ and •OH species contribute a noteworthy role in the degradation process of 2,4-D over 30%-ZnIn 2 S 4 /SO-GCN. In addition, the synthesized nanocomposites sustained their reusability performance in five cyclic run. Our research have implications of constructing 3D/2D nanocomposites which is beneficial for scalable solution of efficient photocatalysts. • Flower like ZnIn 2 S 4 /SO-GCN heterojunction was synthesized by hydrothermal method. • Interfacial microstructures significantly enhanced the photocatalytic performance. • A typical Type II heterostructure was confirmed between SO-GCN and ZnIn 2 S 4. • The degradation rate of 2,4-D by 30%-ZnIn 2 S 4 /SO-GCN was investigated. [ABSTRACT FROM AUTHOR]

Correction for ‘Facile solvothermal synthesis of a high-efficiency CNNs/Ag/AgCl plasmonic photocatalyst’ by Youliang Wang et al., Phys. Chem. Chem. Phys., 2016, DOI: URL10.1039/c6cp04655j/URL. [ABSTRACT FROM AUTHOR]

Abstract Herein, we reported the adsorption and desorption of Pb(II) on l -lysine modified montmorillonite (L-Mt) with molecular dynamics simulation. l -lysine (Lys) modified montmorillonite (L-Mt) was prepared, characterized by various analytical techniques, and the simulation studies were performed to evaluate the interlayer structure and interaction properties of l -lysine and L-Mt. The results of X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) spectrum suggested that Lys+ was intercalated into the interlayer of Na-montmorillonite (Na Mt) successfully. The batch adsorption experiments were implemented to study the adsorption capacity of Pb(II) on L-Mt in water. The maximum adsorption capacity of Pb(II) on the L-Mt (up to 43.3 mmol/100 g) were considerably higher than that on Na Mt (up to 15.3 mmol/100 g), at room temperature. The adsorption isotherms of both, L-Mt and Na Mt can fit the Langmuir isotherm. The adsorption experiments showed that Pb(II) removal efficiency of L-Mt is better than Na Mt in acidic solution. The simulation results revealed the micro-mechanism of Lys+ inserted into the interlayer gallery of Na Mt. It can be deduced that lysine interacted with montmorillonite surface mainly through the protonated side-chain amino group rather than through the protonated main-chain amino group or deprotonated carboxyl group. These consequences are expected to elucidate the adsorption mechanisms occurring at the water/clay minerals interface at atom level, providing significant insight into the adsorption and retention of Pb(II) on L-Mt composite, and lead to relevant engineering applications while treating heavy metals of wastewater. Graphical abstract Unlabelled Image Highlights • l -lysine modified montmorillonite (L-Mt) has higher adsorption capacity for Pb(II) than Na Mt. Their maximum adsorption capacity is 43.3 mmol/100 g and 15.3 mmol/100 g, respectively. • L-Mt is more efficient on the retention of Pb(II) than Na Mt. When pH 3.0, the desorption ratio of Pb(II) is 16.08% and 58.31%, respectively. • The microstructure and interaction between lysine and Na Mt has been revealed by molecular dynamic simulation. [ABSTRACT FROM AUTHOR]

A novel and highly efficient ternary mpg-C 3 N 4 /BiVO 4 /TiO 2 composite was successfully synthesized and characterized with regard to structure, chemical composition, optical properties and degradation application. The photocatalytic activities of as-prepared samples were evaluated by the photocatalytic decomposition of methylene blue (MB), practical effluent from alkylation and amination steps in 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) production. Compared with TiO 2 , BiVO 4, and mpg-C 3 N 4 , the binary composites TiO 2 /BiVO 4 and the ternary mpg-C 3 N 4 /BiVO 4 /TiO 2 composites exhibited the higher photocatalytic activity under visible light irradiation. Compared to solo mpg-C 3 N 4 and BiVO 4 , the photocatalytic efficiency of g-C 3 N 4 /TiO 2 /BiVO 4 raised up to 94%. The catalytic activity of g-C 3 N 4 /TiO 2 /BiVO 4 against TATB (alkylation and amination) also confirms its efficiency by creating intermediate which were detected by Q-TOF-MS. The thermal stability and photo-stability of the produced composites were investigated. From the view of practical application, mpg-C 3 N 4 /BiVO 4 /TiO 2 displayed superior photostability after five times recycle. The mechanism research showed the fitting of band structure among BiVO 4 , g-C 3 N 4, and TiO 2 . The presence of mpg-C 3 N 4 and BiVO 4 can notably adjust the band gap energy and the synergy effects of them can prolong the lifetime of the charge carrier. [ABSTRACT FROM AUTHOR]