Highly efficient Ti3+ self-doped TiO2 co-modified with carbon dots and palladium nanocomposites for disinfection of bacterial and fungi.

High efficiency photocatalysts capable of disinfecting a broad-spectrum microorganisms are needed for the practical application of photodisinfection technology. Herein, we synthesized a highly efficient photodisinfection catalyst composed of Ti3+ self-doped TiO2 decorated with carbon dots (CDs) and palladium nano-photocatalyst, designated as Pd/CDs/Ti3+-TiO2, via a facile hydrothermal-calcination approach. XPS and ESR analyses were performed to verify that the composite contained Ti3+, while TEM imaging and FTIR confirmed that the samples contained CDs. The as synthesized photocatalysts, particularly the 1% Pd/CDs/Ti3+-TiO2 sample, exhibited superior photocatalyzed antibacterial activity to pure TiO2 against E. coli (～6.5 orders of magnitude increase at 30 min). The 1% Pd/CDs/Ti3+-TiO2 photocatalyst also exhibited efficient photodisinfection of five pathogenic agricultural fungi. The dark cytotoxicity of the 1% Pd/CDs/Ti3+-TiO2 nanocomposites was evaluated on HepG2 and Chinese hamster lung (V79) cells via Cell Counting Kit-8 (CCK-8) and found to be minimal. Lastly, the recycling capacity for the photodisinfective activity of the nanocomposites was evaluated and found to be unchanged after five cycles. Four active species were identified as contributing to the photoinduced antimicrobial activity of the catalyst: h+, •O2-, •OH, and e-. Together, our results indicate that Pd/CDs/Ti3+-TiO2 nanocomposites have great potential in agricultural plant pathogen disinfection.

TiO2/Cu2(OH)2CO3 nanocomposite as efficient antimicrobials for inactivation of crop pathogens in agriculture.

TiO2/Cu2(OH)2CO3 nanocomposite were synthesized via a simple in-situ precipitation process, which was applied as efficient antimicrobials for the inactivation of Escherichia coli (E. coli) and Fusarium graminearum (F. graminearum) under simulated solar light. With optimum Cu2(OH)2CO3 amount of 1.8 mol%, the TiO2/Cu2(OH)2CO3 nanocomposite presented the highest antimicrobial activities against E. coli and F. graminearum, and achieved complete inactivation in 80 min, which was far better than that of bare TiO2. The boosted photocatalytic disinfection efficiency was ascribed to the increased light harvesting and efficient charge transfer and separation in the TiO2/Cu2(OH)2CO3 nanocomposite, which resulted in more efficient generation of •OH and •O2- that played important role in the photocatalytic inactivation process. Our work revealed that TiO2/Cu2(OH)2CO3 composite was a promising antimicrobial agent for prevention of pathogenic fungal or bacterial infections in crop protection.

Cellular Response of Escherichia coli to Photocatalysis: Flagellar Assembly Variation and Beyond.

Bacterial cells can be inactivated by external reactive oxygen species (ROS) produced by semiconductor photocatalysis. However, little is known about cellular responses to photocatalysis. For a better understanding of this issue, one strain of Escherichia coli ( E. coli, hereafter named as MT), which has an increased ability to metabolize carbon sources, was screened out from the wild-type (WT) E. coli K12 by repeated exposure to photocatalysis with palladium oxide modified nitrogen-doped titanium dioxide. In this study, transcriptome sequencing of the WT and MT strains that were exposed or unexposed to photocatalysis were carried out. Cellular responses to photocatalysis were inferred from the functions of genes whose transcripts were either increased or decreased. Upregulation of expression of bacterial flagellar assembly genes used for chemotaxis was detected in cells exposed to semilethal photocatalytic conditions of the WT E. coli. Increased capability to degrade superoxide radicals and decreased bacterial flagellar assembly and chemotaxis were observed in MT E. coli compared to WT cells. We conclude that the differences in motility and intracellular ROS between MT and WT are directly related to survivability of E. coli during exposure to photodisinfection.

Carbon dots-decorated Na2W4O13 composite with WO3 for highly efficient photocatalytic antibacterial activity.

Photodisinfection by semiconductors has been proven to be an effective method for achieving antibacterial or antifungal activity. However, the toxicity of the nanomaterial to the environment and organisms is a major concern. Herein, a highly efficient and environmentally friendly photodisinfection material of a carbon dots (CDs) decorated Na2W4O13 composite with WO3 photocatalyst was fabricated via a facile hydrothermal-calcination approach. The TEM (transmission electron microscopy) images showed that CDs decorated the surface of the Na2W4O13 flakes. Compared with the samples without incorporated CDs, the as-synthesized composite of CDs/Na2W4O13/WO3 exhibited excellent antimicrobial activity against E. coli under visible light illumination. Electron spin resonance (ESR) spectroscopy and reactive species scavenging experiments revealed that the hydroxyl radicals and superoxide radical anions played the most important role in the photocatalytic bacterial inactivation. Furthermore, the cytotoxicity of the CDs/Na2W4O13/WO3 composite was evaluated by analyzing the viability of HepG2 and Chinese hamster lung (V79) cells using Cell Counting Kit-8 (CCK-8).

Employing a new 12-connected topological open-framework copper borovanadate as an effective heterogeneous catalyst for oxidation of benzyl-alkanes.

A new 12-connected topological open-framework copper borovanadate with a unique B/V ratio (20/12) and a -B3O7(OH)-Na(µ-OH)[B(OH)2]-B3O7(OH)- connection mode has been hydrothermally obtained and characterized. It not only features the first 3-D copper(II) borovanadate which possesses the largest ratio of TM(2+) and borovanadate anion, but also displays highly catalytic activities for the oxidation of benzyl-alkanes.

A new 3-D open-framework cadmium borovanadate with plane-shaped channels and high catalytic activity for the oxidation of cyclohexanol.

A new 3-D open-framework cadmium borovanadate with 6-connected topology was hydrothermally obtained and structurally characterized. It not only features new cadmium(II) borovanadate which possesses an open-framework structure with unique plane-shaped channels, but also exhibits interesting absorption properties and high catalytic activities for the oxidation of cyclohexanol.

The effect of Li(+) ions on the luminescent properties of a single-phase white light-emitting phosphor α-Sr2P2O7:Dy(3.).

Two series of phosphors, α-Sr2(1-x)Dy2xP2O7 and α-Sr2(1-2x)Dy2xLi2xP2O7, with different x values were synthesized successfully using a conventional solid-state method at high temperature for the first time, and their luminescence properties were investigated comparatively. The effect of Li(+) ions on the luminescence properties of Dy(3+) in α-Sr2P2O7 host, including luminescence intensity, optimal doping concentration, concentration quenching mechanism, and decay behavior, was discussed in detail by considering the defect generation in α-Sr2P2O7:Dy(3+), the charge compensation of Li(+) ions and the role of Li2CO3 as solid flux expected in phosphors. The obtained excitation and emission spectra indicate that these as-prepared phosphors can be excited by ultraviolet light and show white light emission due to the combination of the (4)F9/2→(6)H15/2 and (4)F9/2→(6)H13/2 transitions of Dy(3+) ions. The CIE chromaticity coordinates and color correlated temperature of Dy(3+) emission in the phosphor α-Sr2(1-2x)Dy2xLi2xP2O7 (x = 0.03) with optimal fluorescence intensity was also calculated. The present work could be helpful for understanding the effect of the charge compensator (e.g. Li(+) ion) on the luminescent properties of phosphors with non-equivalent ion-displacement and the design of novel phosphors by efficiently taking advantage of charge compensator (e.g. Li(+) ion).

Template-directed construction of conformational supramolecular isomers for bilayer porous metal-organic frameworks with distinct gas sorption behaviors.

A pair of supramolecular isomers of Co(II)-based metal-organic frameworks can be directionally constructed in virtue of solvent templates, which show diverse bilayer networks and lattice packing with the same Co3 SBUs and organic linkers. The two porous materials show distinct gas sorption behaviors at different temperatures, especially their CO2 sorption selectivity.

A novel open-framework copper borophosphate containing 1-D borophosphate anion with 10-MR windows and 12-MR channels.

A novel open-framework copper borophosphate, Na5KCu3[B9P6O33(OH)3]·H2O (), has been synthesised by a boric acid flux method. Its structure can be viewed as a 3-D open framework constructed by the connection of Cu(II)O6 octahedra and 1-D (4,4)-connected borophosphate anionic structures composed of trigonal-planar BO2(OH) groups, tetrahedral BO4 and PO4 groups. The compound not only features a novel borophosphate anionic partial structure containing 1-D 12-MR channels, but also exhibits ferromagnetic interactions and high catalytic activity for the oxidative degradation of chitosan.

1,2-Di-2-pyridylethyl-ene-phenyl-succinic acid (1/1).

In the title 1:1 adduct, C(10)H(10)O(4)·C(12)H(10)N(2), the two components are linked by O-H⋯N hydrogen bonds to form a one-dimensional chain. The dihedral angle between the pyridine rings is 15.68 (8)° These chains are further inter-connected by weak inter-molecular C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions to generate a three-dimensional network.

A novel open-framework copper borophosphate: Cu(H2O)2[B2P2O8(OH)2].

A new open-framework copper borophosphate was hydrothermally synthesized and structurally characterized. Its structure may be regarded as a layer forming via vertex-sharing BO3(OH) and PO4 tetrahedra bonded together with CuO2(OH)2(H2O)2 octahedral units. The thermal stability and magnetic properties are also discussed.