Qiurong Li

Template-controlled fabrication of hierarchical porous Zn–Al composites with tunable micro/nanostructures and chemical compositions

The properties of materials are largely determined by the microstructures and components of materials. The design of layered double hydroxide (LDH) based composites has garnered much interest as a way of fabricating novel multiscale architectures with tunable micro/nanostructures and chemical compositions. The present study aims at exploiting the Zn–Al composites for controlled synthesis of multi-scale structures and multi-component materials. Firstly, microscaled Al2O3 fibers are successfully fabricated via a simple, convenient, and cost-effective biotemplate method employing paper fibers as bio-templates. Then, the multi-scale architectures are designed by an in situ growth method, which involves direct growth of nanoscaled LDH platelets on the surfaces of Al2O3 fibers. Finally, the multi-component LDH based materials are prepared based on the controlled crystal growth of LDHs and ZnO. The microstructure, morphology, and textural properties of the as-prepared samples are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption/desorption. The experimental results show that the longer reaction times are favorable for the crystal growth of LDHs, and the higher hydrothermal temperatures are favorable for the formation of ZnO. This study shows that the design of multi-scale structures and multi-components Zn–Al composites can be extended for the preparation of other hierarchical LDH based materials with controlled morphological and tunable chemical compositions for separation, catalysis, adsorption, sensor, and optical applications.

Adsorption of fluoride ions onto non-thermal plasma-modified CeO2/Al2O3 composites

AbstractThe CeO2/Al2O3 composites were synthesized by different synthesis methods and applied to remove excessive fluoride ions from water. The resulting materials were examined by scanning electron microscope (SEM), N2 adsorption/desorption, and X-ray diffraction (XRD) analysis. In order to improve fluoride removal efficiency, non-thermal plasma (NTP) was used to modify the surface structure of the composites. Effects of calcination temperature, loading, solution pH, adsorption time, and coexisting anions on adsorption capacity were investigated in detail. The results indicated that the composites synthesized by co-precipitation method exhibit excellent removal efficiency in low-concentration fluoridated water. The appropriate adsorption capacity was achieved in the pH range of 3–10. The NTP-modified composites show high binding capacity for fluoride, where the maximum adsorption capacity of 37.0 mg/g was reached at the initial concentration of 120 mg/L. The kinetics of the fluoride adsorption processes ...

Preparation of biomorphic Ni–Al LDHs using cotton from discarded T–shirt as a template and the adsorption capability for Congo red

Biomorphic Ni–Al layered double-hydroxide (LDH) nanosheets with 3D hierarchical structures were synthesized with cotton from discarded T-shirt as templates. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetry–differential thermal analysis, scanning electron microscopy, and energy-dispersive X-ray diffraction. Adsorption of Congo red (CR) by calcined Ni–Al layered double hydroxides (CLDH) from aqueous solution was investigated in detail. Different conditions were evaluated, including solution pH, amount of adsorbent, initial CR concentration, contact time, and temperature. The adsorption kinetics and equilibrium isotherms of the CLDH were studied by use of pseudo-first-order and pseudo-second-order kinetic models, and the Langmuir, Freundlich, and Dubinin–Radushkevich isotherms. Equilibrium isotherms of uptake of CR by CLDH were a good fit to the Freundlich equation, and the adsorption kinetics of CR followed a pseudo-second-order kinetic model. These results suggest that CLDH may be effective adsorbents for the removal of anionic dyes from wastewater.

Synthesis and Absorption Performance of Acrylic Ester and Hollow Fiber Mgo Nanoparticles Resin Composite

ABSTRACT A new resin composite was prepared through traditional suspension polymerization and used as an adsorbent to remove oil from wastewater. Biomorphic hollow fiber MgO was prepared by template-directed synthesis using cotton as template first. Then the samples were characterized by X-ray diffraction, scanning electron microscope, and thermogravimetric differential thermal analysis. Kinetic characterization of the absorption process was also investigated. In addition, the composite showed excellent oil absorbency and could be reused for at least six times while keeping high oil absorbency. GRAPHICAL ABSTRACT