Ruimin Xing

Superhydrophobic/superoleophilic magnetic polyurethane sponge for oil/water separation

Oil/water separation is a worldwide challenge and addressing this challenge calls for the development of efficient absorbent materials. Here a superhydrophobic/superoleophilic magnetic polyurethane (PU) sponge was fabricated via the facile dopamine self-polymerization to anchor Fe3O4 nanoparticles onto the skeleton of the PU sponge, followed by the introduction of low-surface-energy hydrophobic molecules heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane (FAS-17) on the sponge surface to induce the superhydrophobic transformation. The magnetic PU sponge displays excellent superhydrophobicity and superoleophilicity, and more favorably possesses magnetic responsiveness and superior stability against corrosive solutions; it gave outstanding separation performance under magnetic actuation not only for floating oils on the water surface and heavy organic pollutants under water, but also in the more complex environments such as an acidic solution (pH = 1) and simulated seawater, suggesting great potential in practical oily wastewater treatment. The presented approach provides a facile and easily scalable solution for the design and construction of multifunctional magnetic absorbent materials with low costs for practical applications in the petro-chemical field.

AuPd bimetallic nanoparticle-supported carbon nanotubes for selective detection of dopamine in the presence of ascorbic acid

A carbon nanotube-supported AuPd bimetallic nanoparticle (AuPd/CNT) nanocomposite modified glassy carbon (GC) electrode was fabricated and its catalytic properties towards dopamine (DA) in the presence of ascorbic acid (AA) were studied. AuPd/CNTs were synthesized by the simple chemical reduction of Au and Pd salt precursors with CNTs. Under the optimal detection conditions, the amperometric i–t curve shows a linear response of DA over the range from 0.2 μM to 50 μM with a detection limit of 83 nM (S/N = 3) on AuPd/CNTs–Nafion/GCE. Furthermore, the developed sensor showed excellent anti-interference, reproducibility and stability, and was also proven to be feasible for DA determination in human urine samples, indicating the potential application of this nanocomposite for real sample analysis.

Low Cost and Reliable Electrochemical Sensor for Rutin Detection Based on Au Nanoparticles-Loaded ZnS Nanocomposites

Facile preparation of electrode modified materials with low-cost nanocomposites is an important step to develop highly active electrochemical sensors for mass-market applications. Here we fabricated Au nanoparticles (AuNPs)-loaded ZnS nanocomposites for the sensitive determination of rutin due to the cooperative amplification of the conductivity and catalytic activity of AuNPs on ZnS spheres resulting from the high loading ratio of AuNPs on ZnS spheres. Under the optimal conditions, the developed sensor based on AuNPs-loaded ZnS nanocomposites exhibited excellent electrocatalytic activity towards rutin in a linear range from 1 × 10-7 mol/L to 2 × 10-5 mol/L with a limit of detection of 15.3 nM at a signal-to-noise ratio of 3. Furthermore, the proposed method gave satisfactory results for rutin determination in pharmaceutical tablets, which offer promising potential for rutin electrochemical analysis in serum monitoring or Chinese medical analysis owing to its simplicity, low cost, high sensitivity and good stability.

Platinum–Copper Bimetallic Alloy Nanoflowers as Efficient Electrocatalyst for the Methanol Oxidation Reaction

Special morphological noble metal-based bimetallic alloy nanostructures became popular for methanol oxidation reaction in order to reduce the high cost of the Pt catalyst and improve the catalyst activity. Herein, we developed a facile one pot hydrothermal method for the synthesis of platinum-copper bimetallic nanoflowers (Pt-Cu NFs) in the presence of hexadecyl trimethyl ammonium bromide (CTAB). The morphology, structure and composition of Pt-Cu NFs were carefully characterized and the synthesized parameters were optimized systematically by adjusting different experimental conditions. Results showed that the CTAB usage and the NaI amount were critical to the controlled synthesis of Pt-Cu NFs. The Pt-Cu NFs were high-performance electrocatalysts for the methanol oxidation reaction (MOR) with superior activity and superior stability in alkaline solution, which were far better than pure Pt nanoparticle electrocatalysts.

Sensitive Detection of Rifampicin Based on Au-Carbon Nanocomposite

Gold nanoparticles-supported Cabot Vulcan XC72R (Au/VXC72R) nanocomposite was synthesized by chemical reduction of gold (III) chloride with VXC72R. A novel electrochemical sensor based on the Au/VXC72R nanocomposite has been fabricated for the sensitive detection of rifampicin (RIF). Field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology, structure and compositions of the nanocomposite. Under the optimal conditions, the Au/VXC72R-chitosan/GCE can be used to determine RIF concentration in a linear range from 5 × 10-7 mol/L to 1 × 10-5 mol/L with the detection limit of 1.1 × 107 M (S/N = 3). The proposed approach exhibits good stability, acceptable reproducibility and applicability, which will probably bring widespread applications in quality monitoring in real samples.

CdS/ZnS Heterostructured Porous Composite with Enhanced Visible Light Photocatalysis

Fabrication of semiconductor composites consisting of multicomponent or multiphase heterojunctions is a very effective strategy to design highly active photocatalyst systems. Here we present a facile design to fabricate novel CdS/ZnS heterostructured porous sheet-like nanocomposite based on a cation-exchanged hydrothermal procedure. Micro-structural analyses reveal that the product is a kind of heterostructured composite with porous structure and high crystallinity. The composite nanosheets exhibited enhanced visible-light photoactivity compared with pure ZnS or CdS. Among them, sample of Cd0.45Zn0.55S gave the highest degradation rate of about 99% under visible-light irradiation within 60 min when 10 mg of the sample was added into 50 mL of methyl orange in aqueous solution (10 mg/L). The enhanced photocatalytic activity was presumed to result from the direct photoinduced interfacial charge transfer (IFCT) from the valence band (VB) of ZnS to CdS.

Sensitive Determination of Dopamine and Paracetamol Based on Carbon Nanotubes-Supported Pd Nanoparticles

A novel chemically modified electrode was constructed in this study based on the carbon nanotubes-supported Pd nanoparticles (Pd/CNTs). It was demonstrated that the sensor could be used for the determination of dopamine (DA) and paracetamol (PA). The measurements were carried out through application of cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometric i-t curve. Under optimum conditions and using the amperometric i-t curve method, the modified electrode provided linear response versus dopamine concentrations in the range of 0.3 × 10-6-5.0 × 10-5 M and PA concentrations in the range of 0.2 × 10-6-6.0 × 10-5 M, respectively. The detection limits for the DA and PA were 9.1 × 10-8 M and 8.9 × 10-8 M (S/N = 3), respectively. The sensitivities for of the electrode were 0.928 and 1.532 μA μM-1 cm-1, respectively.

ODS – modified TiO2 nanoparticles for the preparation of self-cleaning superhydrophobic coating

Rolling water drops takes off dust particles from lotus leaf showing self-cleaning performance. Self-cleaning effect has great importance in industry as well as in daily life. The present paper describes the preparation of self-cleaning superhydrophobic coating through simple and low cost dip coating technique. The prepared superhydrophobic surface enact as lotus leaf. Firstly TiO2 nanoparticles were dispersed in ethanol and different concentration of octadecyltrichlorosilane (ODS) was added in TiO2 dispersion. The effect of number of deposition layer on the wettability of the coating was studied. The coating prepared from five deposition layers showed contact angle higher than 150° and sliding angle less than 10°. The superhydrophobicity increases with increasing concentration of ODS. The hierarchical rough morphology which is preferable for superhydrophobicity was obtained. The prepared coatings were stable against water jet impact and showed repellent towards colored and muddy water. Such superhydrophobic coating can find enormous scope in self-cleaning application.Rolling water drops takes off dust particles from lotus leaf showing self-cleaning performance. Self-cleaning effect has great importance in industry as well as in daily life. The present paper describes the preparation of self-cleaning superhydrophobic coating through simple and low cost dip coating technique. The prepared superhydrophobic surface enact as lotus leaf. Firstly TiO2 nanoparticles were dispersed in ethanol and different concentration of octadecyltrichlorosilane (ODS) was added in TiO2 dispersion. The effect of number of deposition layer on the wettability of the coating was studied. The coating prepared from five deposition layers showed contact angle higher than 150° and sliding angle less than 10°. The superhydrophobicity increases with increasing concentration of ODS. The hierarchical rough morphology which is preferable for superhydrophobicity was obtained. The prepared coatings were stable against water jet impact and showed repellent towards colored and muddy water. Such superhydropho...