In situ construction of Ag/Bi2O3/Bi5O7I heterojunction with Bi-MOF for enhance the photocatalytic efficiency of bisphenol A by facet-coupling and s-scheme structure.

In this study, Ag/Bi2O3/Bi5O7I with s-scheme heterostructures were successfully synthesized in situ by nano-silver modification of CUA-17 and halogenated hydrolysis.The growth rate of Bi2O3 crystals was effectively controlled by adjusting the doping amount of Ag, resulting in the formation of a facet-coupling heterojunctions. Through the investigation of the microstructure and compositional of catalysts, it has been confirmed that an intimate facet coupling between the Bi2O3 (120) facet and the Bi5O7I (312) facet, which provides robust support for charge transfer. Under visible light irradiation, the AgBOI.3 heterojunction photocatalyst exhibited an outstanding degradation rate of 98.2% for Bisphenol A (BPA) with excellent stability. Further characterization using optical, electrochemical, impedance spectroscopy, and electron spin resonance techniques revealed significantly enhanced efficiency in photogenerated charge separation and transfer, and confirming the s-scheme structure of the photocatalyst. Density functional theory calculations was employed to elucidate the mechanism of BPA degradation and the degradation pathway of BPA was investigated by LC-MS. Finally, the toxicity of the degradation intermediates was evaluated using T.E.S.T software.

Carboxyl-functionalized covalent organic frameworks for the extraction of malachite green and crystal violet in environmental water samples prior to quantification by high-performance liquid chromatography.

In this study, monodisperse, uniform, and spherical covalent organic frameworks (COFs) were synthesized using 1,3,5-tris (4-aminophenyl) benzene and 1,3,5-tricarboxaldehyde benzene at room temperature. Post-modification of 6-aminocaproic acid on the COFs yielded carboxyl-modified COFs (COFs-COOH). The modification enhanced the hydrophilicity and adsorption efficiencies of COFs-COOH for malachite green (MG) and crystal violet (CV). A COFs-COOH-based dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed for the analysis of MG and CV. The method showed a linear range from 10 to 1000 ng/mL with detection limits of 1.82 and 0.70 ng/mL for MG and CV detection, respectively. The recoveries of MG and CV from water samples collected from fish farms and markets ranged from 91.63% to 107.10% with relative standard deviations below 5%. Reproducibility tests demonstrated that the adsorption efficiencies of COFs-COOH were maintained at above 85.86% over 15 cycles. The study verified the potential of COFs-COOH as sorbents for the enrichment and separation of triphenylmethane dyes from complex samples.

CoFe-Layered Double Hydroxide Coupled with Pd Particles for Electrocatalytic Ethanol Oxidation.

Electrocatalytic efficiency and stability have emerged as critical issues in the ethanol oxidation reaction (EOR) of direct ethanol fuel cells. In this paper, Pd/Co1Fe3-LDH/NF as an electrocatalyst for EOR was prepared by a two-step synthetic strategy. Metal-oxygen bonds formed between Pd nanoparticles and Co1Fe3-LDH/NF guaranteed structural stability and adequate surface-active site exposure. More importantly, the charge transfer of the formed Pd-O-Co(Fe) bridge could effectively modulate the electrical structure of hybrids, improving the facilitated absorption of OH- radicals and oxidation of COads. Benefiting from the interfacial interaction, exposed active sites, and structural stability, the observed specific activity for Pd/Co1Fe3-LDH/NF (17.46 mA cm-2) was 97 and 73 times higher than those of commercial Pd/C (20%) (0.18 mA cm-2) and Pt/C (20%) (0.24 mA cm-2), respectively. Besides, the jf/jr ratio representing the resistance to catalyst poisoning was 1.92 in the Pd/Co1Fe3-LDH/NF catalytic system. These results provide insights into optimizing the electronic interaction between metals and the support of electrocatalysts for EOR.

A 2-Hydroxy-1-naphthaldehyde Schiff Base for Turn-on Fluorescence Detection of Zn2+ Based on PET Mechanism.

Zinc ion is closely related to human health. Its content in human body is small, while the effect is large. However, it is not the more the better, must be in a scientific balance. Therefore, it is significant to the rapid detection of Zn2+ in the environment and organism. Herein, a fluorescent probe based on 2-hydroxy-1-naphthalene formaldehyde and furan-2-carbohydrazide was conveniently synthesized via Schiff base reaction. And this probe has been successfully applied to the accurate and quantitative detection of Zn2+ in real samples, showing turn on fluorescence, good selectivity, very low detection limit, real time response and reusability. In addition, this probe has the potential application to trace Zn2+ in living cells with low cytotoxicity.

A ratiometric fluorescent probe for the rapid and specific detection of HSO3 - in water samples.

Hydrosulphite (HSO3 - ), as a common and important chemical reagent, is widely used in everyday life, however excessive use and abuse of HSO3 - can cause potential harmful effects on the environment and in biological health. In this paper, we describe the design and preparation of a colorimetric and ratiometric fluorescence probe for the visual detection of HSO3 - (excitation wavelengths were, respectively, 336 nm and 520 nm). This method showed some advantages including simple preparation, high selectivity, fast response, and significant colour and fluorescence ratio (F450 /F594 ) changes in the presence of HSO3 - . In addition, this probe was used successfully for the detection of HSO3 - in real water samples and showed a good recovery rate range.

Determination of proteins with tetracarboxy manganese(II) phthalocyanine by resonance light scattering technique.

A novel method for the determination of proteins by using tetracarboxy manganese(II) phthalocyanine (MnC4Pc) as a resonance light scattering (RLS) probe has been developed. At pH 3.0 Britton-Robinson (B-R) buffer solution, the RLS intensity of MnC4Pc at 385 nm is greatly enhanced in the presence of proteins. The effects of pH, reaction time, concentration of MnC4Pc and interfering substances on the enhanced RLS intensity are investigated, respectively. Under optimal conditions, the linear ranges of the calibration curves are 0-2.00 microg mL(-1) for bovine serum albumin (BSA) and human serum albumin (HSA), 0.0-1.75 microg mL(-1) for human-IgG and ovalbumin, with a detection limit of 16.37 ng mL(-1) BSA, 17.62 ng mL(-1) HSA, 19.41 ng mL(-1) human-IgG and 20.72 ng mL(-1) ovalbumin. The method has been applied to the determination of total proteins in human serum samples collected from a hospital and the results are in good agreement with those reported by the hospital.