Unraveling charge transfer dynamics in AgBr/Bi4Ti3O12/Bi2Sn2O7 ternary S-scheme heterojunction photocatalyst.

In this study, AgBr/Bi4Ti3O12/Bi2Sn2O7 (ABr/BTO/BSO) composites were successfully synthesized to facilitate multi-channel fast charge transfer. This directs the charge carriers to travel along multichannel pathways and suppresses carrier recombination. The mechanisms underlying charge transfer in the dual S-scheme heterojunction composites were elucidated using density functional theory (DFT) and in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS). Furthermore, electron spin resonance (ESR) and burst experiments verified h+, ·O2 -, and ·OH as the primary active species in the catalytic process. The ABr/BTO/BSO composites demonstrated exceptional photocatalytic redox capabilities, completely degrading rhodamine B (RhB) and achieving degradation rates of 77.21% for tetracycline (TC) and 81.04% for Cr (VI). Both experimental and theoretical analyses confirmed the intrinsic efficacy of photo-induced electron movement within the composites. This research introduces innovative design concepts and strategies for the advanced exploration of electron channel transfer in ABr/BTO/BSO ternary composites and the development of novel composite photocatalytic systems.

Catalytic degradation of rhodamine B by titanium dioxide doped polydopamine photoresponsive composites.

Titanium dioxide-based materials treat wastewater contaminated by organic pollutants. However, the wide band gap and the ease of agglomeration limit its photocatalytic activity. PDA/PEI@TiO2@P-HSM composites were synthesized using PDA/PEI as an interfacial bonding modifier via polymerization reaction. Phase and chemical bonding analysis confirmed the modifiedTiO2 coated P-HSM, which can effectively reduce the band gap and control the agglomeration of titanium dioxide, i.e., suitable to degrade RhB. Under UV irradiation, PDA/PEI @TiO2@P-HSM can remove RhB up to 90 % in 100 min. The photocatalytic degradation process conforms to the Langmuir-Hinshelwood quasi-primary equation. The composite exhibited excellent stability and recycling i.e., a high removal effect, with a removal rate of up to 60 % after seven cycles of reaction.

Amino-modified chitosan/gold tailings composite for selective and highly efficient removal of lead and cadmium from wastewater.

In this work, a novel amino-modified chitosan/tailings composite (CS-PEI-nGT) was successfully synthesized from gold tailings particle treated by ball milling (nGT), chitosan (CS) and polyethyleneimine (PEI) as raw materials, for Lead (Pb(Ⅱ)) and Cadmium (Cd(Ⅱ)) removal from aqueous solutions. The CS-PEI-nGT was characterized by using FTIR, XRD, SEM, BET, TGA and XPS techniques. The results showed that CS-PEI-nGT had maximum adsorption capacity of 192.78 mg·g-1 and 99.46 mg·g-1 for Pb(Ⅱ) and Cd(Ⅱ) respectively at pH 5. The adsorption kinetics was described well by pseudo-second-order kinetic adsorption model, and suggested that chemisorption as the rate-controlling step for adsorption of Pb(Ⅱ) and Cd(Ⅱ). The isotherm data was accurately explained by Langmuir model with higher correlation coefficient (R2) of 0.9911 and 0.9642 for Pb(Ⅱ) and Cd(Ⅱ) respectively. In addition, CS-PEI-nGT retained its selective adsorption capacity for Pb(Ⅱ) and Cd(Ⅱ), compared to other metals such as Zn(Ⅱ), Mn(Ⅱ), Mg(Ⅱ) and Al(Ⅲ). The mechanism of the adsorption was investigated and the results revealed that amino (-NH2), silicon oxide groups (Si-O) and hydroxyl (-OH) functional groups on composite surface were accountable for metals adsorption, suggesting surface complexation, electrostatic interactions and ion exchange. Our work presents a promising strategy for tailings recycling and highly efficient removal of toxic metals ions from wastewater.

Immobilization properties and adsorption mechanism of nickel(II) in soil by biochar combined with humic acid-wood vinegar.

Biochar (BC) combined with humic acid (HA) and wood vinegar (WV) was designed and prepared as an inexpensive, effective, and environmentally friendly immobilization material (BHW) for metal-polluted soil. The influences of the wood vinegar and humic acid on the immobilization properties and adsorption mechanism of this new material were also investigated. The remediation performance was evaluated using a laboratory-made, nickel-contaminated soil with a Ni2+ concentration of 200 mg per kg surface soil (top 20 cm from agricultural land). The results indicated that the immobilization ratio sequence of nickel (II) in the soil was BC< BH< BHW. The maximum adsorption capacity increased in the same order: BC< BH< BHW. All three adsorption isotherms were better fitted by the Freundlich model, which were consistent with the surface heterogeneity of the remediation materials. The cause of this surface heterogeneous migration may be due to the increase in oxygen-containing groups in the BC introduced by the HA and WV. The WV can increase the number of the oxygen-containing groups in the BC combined with HA, which enhanced the adsorption and immobilization of Ni2+ ions. The results suggested that BHW is recommended for the remediation of metal-contaminated soils, because of its high efficacy, economic feasibility, environmental and food safety.

Feasibility of vermicomposting for spent drilling fluid from a nature-gas industry employing earthworms Eisenia fetida.

This study investigated the vermicomposting of spent drilling fluid (SDF) from the nature-gas industry mixed with cow dung in 0% (T1), 20% (T2), 30% (T3), 40% (T4), 50% (T5), and 60% (T6) ratio employing Eisenia fetida under a 6 weeks trial. Eisenia. fetida showed better growth and reproduction performances in the first three vermireactors (T1-T3), and the mortality was higher in the vermireactors that contained more spent drilling fluid (≥40%). Vermicomposting results in a decrease in total organic carbon, C/N ratio, and an increase in EC, total nitrogen, total phosphorous, total potassium compared to their initial values. The RadViz and VizRank showed that vermicomposting results in a greater impact on the C/N ratio (15.24-35.48%) and EC (7.29-26.45%) compared to other parameters. Activities of urease and alkaline phosphatase during vermicomposting initially increased and then declined suggesting vermicompost maturity. Also, seed germination, mitotic index and chromosomal abnormality assays using cowpea signified that the vermicomposts T2 is suitable for agricultural use due to the lower phytotoxicity and cytotoxicity. The results indicated that SDF could be converted into good quality manure by vermicomposting if mixed up to 20% with cow dung.

Wood vinegar enhances humic acid-based remediation material to solidify Pb(II) for metal-contaminated soil.

Heavy metal lead is a typical widespread potentially toxic element (PET) contamination due to their extensive and wide applications in industrial processes. The development of cost-effective methods for preventing potentially toxic element lead residues from soil into food is thus highly desirable. A new type of humic acid-based remediation material (HA/WV) incorporating humic acid salt (HA), biochar powder (BC), and wood vinegar (WV), which is a cheap and environmentally friendly industrial by-product from charcoal processing, was prepared and evaluated. The results showed that 0.10 g remediation material HA/WV with a mass ratio of 1:1 was added to 1 kg surface soil of 0-20 cm from agricultural land contaminated by 300 mg Pb2+, the reduction ratio of available Pb in soil can reach 61.4%. Especially, wood vinegar can enhance the reduction ratio of available Pb by at least 14.7% over without wood vinegar. Furthermore, according to the analysis of adsorption interaction and the electrostatic attraction between Pb(II) and oxygen-containing functional groups on HA/WV are the dominant mechanisms responsible for Pb(II) sorption. The wood vinegar liquid can improve the oxygen-containing group in HA/WV, which can enhance the complexation of remediation materials and Pb(II) ion.

pH-Responsively Water-Retaining Controlled-Release Fertilizer Using Humic Acid Hydrogel and Nano-Silica Aqueous Dispersion.

A pH-responsively controlled-release fertilizer was prepared using humic acid (HA) hydrogel, Nanosilica aqueous dispersion (NSAD) and sodium alginate (SA). Therein, the NSAD was modified with HA owning a variety of reactive groups and good compatibility by the hydrogen bonding and playing a skeleton supporting role in the entire structural system, SA was soluble in alkaline environments thus releasing the HA. The facts showed that the gel fertilizer had a good controlled release effect and the HA was released organically in alkaline environments through structural characterization and controlled release mechanism experiments. The application test showed that the humic acid sustained-release fertilizer has obvious improvement effect on saline-alkali soil.

Interactions between fluorinated cationic guar gum and surfactants in the dilute and semi-dilute solutions.

The interactions between the fluorinated cationic guar gum (FCGG) and ionic surfactants including cetyl trimethyl ammonium bromide (CTAB) and sodium lauryl sulfate (SDS) were studied by light scattering, fluorescence spectroscopy, UV-spectrophotometer, (19)F NMR and dynamic rheometer, respectively. The FCGG is prepared with cationic guar gum, isophorone diisocyanate and 2,2,3,4,4,4-hexafluoro-1-butanol. The results show that, with the addition of the surfactants, the stretching degree of the FCGG chains is increased in the FCGG/CTAB solutions, while the dramatical shrinking of FCGG chain, the phase separation and the re-stretched macromolecules appear successively because of the electricity neutralization reaction in the FCGG/SDS system. The mixed hydrophobic domains in all solutions will be reinforced and then dismantled. The solution elasticity shows up the maximum value accordingly. The surfactants can be embedded in the micro-domains and then hinder the fluorinated segmental motions. The interactions between FCGG and SDS are much stronger than those between FCGG and CTAB.

Gene diagnosis for nine Chinese patients with DMD/BMD by multiplex ligation-dependent probe amplification and prenatal diagnosis for one of them.

This study aims to perform gene diagnosis for nine patients with Duchenne/Becker muscular dystrophy (DMD/BMD) and their parents with multiplex ligation-dependent probe amplification (MLPA), and to carry out prenatal gene diagnosis for one of them. Genomic DNA of the peripheral blood and fetal amniotic fluid cell was extracted from the pedigrees' members with DMD/BMD. Gene diagnosis was performed for theses pedigrees' members using a SALSA KIT. Short tandem repeats (STR) genotyping and X-linkage analysis were performed for the pedigree members of the fetus, which was used in the prenatal diagnosis. MLPA analysis results show that five of nine patients (DMD-1, DMD-2, DMD-4, DMD-8, and DMD-9) with DMD/BMD were found to have several hemizygous exon deletions in the dystrophin gene. The other patients and the fetus did not have any hemizygous deletion or duplication of any exons. The genomic DNA of the fetus was not contaminated by his mother's DNA as identified by STR genotyping. In addition, X-linkage analysis results show that the only X chromosome of the fetus comes from one of his mother's normal X chromosomes. Combined with STR genotyping and X-linkage analysis, MLPA is a convenient, highly effective and reliable gene diagnosis technique for congenital genetic disease.

High-efficiency polymer light-emitting diodes using neutral surfactant modified aluminum cathode.

High-efficiency polymer light-emitting diodes were fabricated by inserting a layer of nonionic neutral surfactant between the electroluminescent (EL) layer and the high-work-function aluminum cathode via spin coating. It was found that both the poly(ethylene glycol)- and poly(propylene glycol)-based surfactants as well as their copolymers can all demonstrate similar performance enhancement. Device performances comparable to or even better than those of the control devices using calcium as the cathode have been achieved for both poly(p-phenylene)-based and polyfluorene-based conjugated polymers with orange-red, green, and blue emission colors. It is possible that when both surfactant and aluminum are used as the cathode, the abundant hole injection through a hole-transporting layer and hole pile-up at the inner side of the EL/surfactant interface might cause an effective electric field to induce the realignment of the dipole moment of those polar surfactant molecules, thus lowering the barrier for electron injection. In addition, the coordination between the aluminum and oxygen atoms on the surfactant might cause n-type doping in the areas near surfactant in the EL polymer layer that causes the enhancement of electron injection.

Efficient CdSe/CdS quantum dot light-emitting diodes using a thermally polymerized hole transport layer.

We report multilayer nanocrystal quantum dot light-emitting diodes (QD-LEDs) fabricated by spin-coating a monolayer of colloidal CdSe/CdS nanocrystals on top of thermally polymerized solvent-resistant hole-transport layers (HTLs). We obtain high-quality QD layers of controlled thickness (down to submonolayer) simply by spin-coating QD solutions directly onto the HTL. The resulting QD-LEDs exhibit narrow ( approximately 30 nm, fwhm) electroluminescence from the QDs with virtually no emission from the organic matrix at any voltage. Using multiple spin-on HTLs improves the external quantum efficiency of the QD-LEDs to approximately 0.8% at a brightness of 100 cd/m(2) (with a maximum brightness over 1,000 cd/m(2)). We conclude that QD-LEDs could be made more efficient by further optimization of the organic semiconductors.

A highly electroluminescent molecular square.

Chiral molecular triangles and squares containing the Pt(diimine) metallocorners were synthesized and characterized, and used as the triplet MLCT luminophore in highly efficient light-emitting devices.