Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

Sensitive and selective colorimetric detection of cadmium(II) using gold nanoparticles modified with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole

Abstract: We have developed a simple, sensitive and selective colorimetric method for the detection of cadmium(II) (Cd2+) using gold nanoparticles modified with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole. Organic solvents or additives are not required. It is found that Cd2+ induces the aggregation of the modified Au-NPs via chelation, leading to a color change from red to blue. This change can be seen with bare eyes, and monitored by UV–vis spectroscopy, transmission electron microscopy and dynamic light scattering. The detection limit is 30 nM (at a signal-to-noise ratio of 3). The new approach was successfully applied to the detection of Cd2+ in spiked samples of tap water and lake water, and the results agree well with those obtained by flame atomic absorption spectroscopy.

An aqueous synthesis of porous PtPd nanoparticles with reversed bimetallic structures for highly efficient hydrogen generation from ammonia borane hydrolysis

Abstract: Fine construction of porous bimetallic nanomaterials with tunable components and structures is of great importance for their catalytic performance and durability. Herein, we present a facile and mild one-pot route for the preparation of porous PtPd bimetallic nanoparticles (NPs) with reversed structures in aqueous solution for the first time. To this end, a common ionic liquid (IL) 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl) is utilized to direct the growth and assembly of porous structures of PtPd NPs. It is shown that the as-prepared porous Pt25Pd75 NPs have obvious hierarchical structures with nanoflowers as subunits and nanorods as basic units. The elemental components and structures of the porous PtPd NPs can be tuned by the precursor ratio and the [C16mim]Cl concentration. Furthermore, various porous PtPd bimetallic structures from Pd-on-Pt to Pt-on-Pd may be efficiently switched by controlling the concentration of glycine. Owing to their high specific surface area, porous hierarchical structures (including mesopores and micropores), and probable electronic effects between Pt and Pd, the porous Pt25Pd75 NPs (Pd-on-Pt structure) are found to exhibit prominent catalytic activity and high stability for hydrogen production from hydrolysis of ammonia borane.

Hierarchical TiO2 microspheres comprised of anatase nanospindles for improved electron transport in dye-sensitized solar cells

Abstract: Hierarchical TiO2 microspheres assembled by nanospindles were prepared via a two-step hydrothermal method. The as-prepared products have uniform diameters of ∼450 nm and surface area of ∼88 m2 g−1. The optical investigation evidenced that the photoanode film has a prominent light scattering effect at a wavelength range of 600–800 nm and possesses enhanced dye loading capacity. In addition, the electron recombination and transport dynamic measurements indicated that these hierarchical products could suppress the recombination and improve the diffusion coefficient of the photoelectrons, which can be attributed to the improvement of the connectivity by bridging the neighbouring microspheres through the embedded nanospindles. As a result, a high power conversion efficiency of 8.5% was demonstrated, indicating a ∼30% improvement compared with the cell derived from the well-defined nanocrystalline microspheres (6.5%).

Plant Growth, Antibiotic Uptake, and Prevalence of Antibiotic Resistance in an Endophytic System of Pakchoi under Antibiotic Exposure

Abstract: Antibiotic contamination in agroecosystems may cause serious problems, such as the proliferation of various antibiotic resistant bacteria and the spreading of antibiotic resistance genes (ARGs) in the environment or even to human beings. However, it is unclear whether environmental antibiotics, antibiotic resistant bacteria, and ARGs can directly enter into, or occur in, the endophytic systems of plants exposed to pollutants. In this study, a hydroponic experiment exposing pakchoi (Brassica chinensis L.) to tetracycline, cephalexin, and sulfamethoxazole at 50% minimum inhibitory concentration (MIC) levels and MIC levels, respectively, was conducted to explore plant growth, antibiotic uptake, and the development of antibiotic resistance in endophytic systems. The three antibiotics promoted pakchoi growth at 50% MIC values. Target antibiotics at concentrations ranging from 6.9 to 48.1 µg·kg-1 were detected in the treated vegetables. Additionally, the rates of antibiotic-resistant endophytic bacteria to total cultivable endophytic bacteria significantly increased as the antibiotics accumulated in the plants. The detection and quantification of ARGs indicated that four types, tetX, blaCTX-M, and sul1 and sul2, which correspond to tetracycline, cephalexin, and sulfamethoxazole resistance, respectively, were present in the pakchoi endophytic system and increased with the antibiotic concentrations. The results highlight a potential risk of the development and spread of antibiotic resistance in vegetable endophytic systems.