3D flower-liked Fe3O4/C for highly sensitive magnetic dispersive solid-phase extraction of four trace non-steroidal anti-inflammatory drugs.

A low cost-effective and simple synthesis method was adopted to acquire three-dimensional flower-like structure Fe3O4/C that has large specific area, suitable pore structure and sufficient saturation magnetism. The obtained Fe3O4/C exhibits outstanding preconcentration ability and was applied to extracting non-steroidal anti-inflammatory drugs from complex environmental and biological samples. The parameters of magnetic solid-phase extraction were optimized by univariate and multivariate methods (Box-Behnken design). The high degree of linearity from 2.5 to 1000.0 ng mL-1 (R2 ≥ 0.9976), the limits of detection from 0.25 to 0.5 ng mL- 1 (S/N = 3), and the limits of quantitation from 1.0 to 2.0 ng mL- 1 (S/N = 10) were yielded by adopting this novel method after the optimization. Moreover, the recoveries of non-steroidal anti-inflammatory drugs from 89.6 to 107.0% were acquired in spiked plasma, urine and lake samples. In addition, the adsorption of non-steroidal anti-inflammatory drugs on Fe3O4/C was explored by adsorption isotherms and kinetic studies. Furthermore, the adsorption mechanism for non-steroidal anti-inflammatory drugs by Fe3O4/C was proposed, which was hydrogen bonding and π-π interaction between non-steroidal anti-inflammatory drugs and Fe3O4/C. Graphical abstract.

Flower-Like MoS2 for Next-Generation High-Performance Energy Storage Device Applications.

Here, a well crystalline 3D flower-like structured MoS2 (~420 nm) has been successfully synthesized on a large scale by a simple hydrothermal technique. The evolution of morphology in the formation process has also been investigated. The crystallinity, purity, and morphology of the sample are characterized by powder X-ray diffraction, Fourier-transform infrared spectroscopy, fieldemission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. The FESEM and TEM images reveal that the sample exhibits a uniform 3D flower-like microsphere shape with folded nanosheets, which are stretched out along the edge of the microsphere. The electrochemical performance of the sample has been investigated by cyclic voltammogram, galvanostatic charge-discharge, and electrochemical impedance spectroscopy studies. The results of the electrochemical analysis suggest that the material delivers a maximum specific capacitance (Csp) of 350 F/g at a discharge current density of 0.25 A/g with energy density 17.5 Wh/kg. It also exhibits good capability and excellent cyclic stability (94% capacity retention after 1,000 cycles in 1 A/g) owing to the coupling effect of electrical conductivity with the interesting morphology and larger active surface area. Hence, the sample may be used as a promising electrode material for high-performance energy storage devices.

3D flower-like zirconium magnesium oxide nanocomposite for efficient fluoride removal.

A 3D flower-shaped bimetallic nanocomposite zirconium magnesium oxide (ZMO) was prepared first time by the controlled solution combustion method using triethanolamine (TEA) as a fuel and chelating agent. The composite material was used to remove excess fluoride via adsorption. The thermal stability of the adsorbent was characterized by thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to characterize the adsorbent. The surface charge of the nano adsorbent was determined by Zeta Sizer. The surface area and pore volume of the adsorbent were determined by Brunauer-Emmett-Teller (BET) isotherm and Barrett-Joyner-Halenda (BJH) methods. The adsorption behavior of fluoride was studied systematically varying the pH, contact time, adsorbent dose, and initial fluoride concentration. The adsorption followed the Langmuir isotherm model with a maximum adsorption capacity of 42.14 mg/g. The pseudo-second-order kinetic model was confirmed by the adsorption study. The maximum adsorption efficiency was in the 6-10 pH range. The reaction mechanism was mainly based on ion exchange between hydroxy and fluoride ions which was proven by X-ray photoelectron spectroscopy (XPS). Real water tests indicated that ZMO could be used as a potential defluoridation agent for fluoride containing groundwater treatment.

Biomass-derived carbon dots regulating nickel cobalt layered double hydroxide from 2D nanosheets to 3D flower-like spheres as electrodes for enhanced asymmetric supercapacitors.

Layered double hydroxides (LDHs) often require the use of carbon materials to improve their stability, conductivity, and specific surface area to accommodate new directions in the development of high-performance energy storage materials. Herein, 2D nickel cobalt layered double hydroxide (NCLDH) nanosheets are regulated to form 3D flower-like spheres by fungus bran-derived carbon dots (CDs) via an in situ growth method. The prepared sample (CDs/NCLDH) shows abundant accessible active sites and favorable electrical conductivity, which is aided by strong interactions between CDs and NCLDH. The optimized CDs/NCLDH exhibits significantly enhanced electrochemical performances, including ultrahigh specific capacitance (2100F g-1 at 1 A g-1) and a great rate capability, which are two times higher than those of the NCLDH electrode. Additionally, the asymmetric supercapacitor device assembled with the CDs/NCLDH positive electrode and the fungus bran-derived activated carbon (FBC) negative electrode achieves a superior energy density of 52.5 Wh kg-1 at an ultrahigh powder density of 750 W kg-1. With their simple synthesis method and excellent electrochemical performance, the role of the CDs provides new insights for the development of LDHs with improved performance.