Zhibin Zhu

Hydrothermal synthesis of nano nickel phosphides and investigation of their thermal stability

Abstract Nanometer scale nickel phosphide particles (Ni2P and Ni12P5) were synthesized via a mild hydrothermal method with red phosphor and nickel chloride as raw materials. X-ray diffraction, energy dispersive spectrometry, transmission electron microscopy, scanning electron microscopy and differential thermal analysis–thermogravimetric analysis were employed to characterize the resulting products. The results showed that the as-prepared products were well crystallized and particle sizes ranged from 10 to 40 nm. Investigation of raw material ratios and initial pH of the reaction system showed increasing P/Ni ratio did benefit the formation of Ni2P but went against obtaining Ni12P5 and nano-particles were obtained only in an alkaline environment. Subsequent differential thermal analysis–thermogravimetric analysis indicated that Ni2P remained as the major phase till 500 °C in an air atmosphere.

Colorimetric and fluorometric dual-mode detection of aniline pollutants based on spiropyran derivatives

The selective UV-vis absorption of spiropyran (SP) and the fluorescence quenching of a SP-cellulose material induced by aniline were observed in this study, which were exploited for rapid detection and accurate quantitative determination of aniline pollutants in the environment. The concentration of aniline pollutants can be rapidly evaluated by the naked eye in a colorimetric and fluorometric dual-mode by the SP-cellulose test paper. Furthermore, the aniline pollutants can also be accurately determined using the above materials with the aid of portable spectrophotometers. The detection processes are effective, low cost and easy to operate, and do not require personnel with expertise or cumbersome equipment, and are therefore especially suitable for real-time-field monitoring of aniline pollutants outdoors.

Anisotropic Growth of Porous Anodic Alumina and Its Potential Application in Three-Dimensional Nanostructure Construction

The porous anodic alumina was fabricated by means of electrochemical oxidation using Al foil as a substrate in oxalic acid under constant anodic voltage at room temperature. Prior to anodization, the substrate surface with roughness in microscale was obtained through electrochemical treatment. The tube growth on the substrate was investigated using a scanning electron microscope (SEM). The results showed that the tube growth behavior of the porous anodic alumina was strongly dependent on the surface roughness. In presence of sphere-shaped cavities in microscale (diameter of 5~30 μm) on the surface of the substrate, the nanotubes were growing essentially away from the center of curvature of each cavity, forming individual growing regions separated by visible interface. The tube branching and tube cutoff were evidently observed in the growing regions and along the interface, respectively. Anisotropic growth of porous anodic alumina suggested its potential application in three-dimensional nanostructure construction.