Chung-Shin Lu received his PhD degree in Chemistry from the Tsing Hua University, Taiwan, in 1994. He is currently a Professor at the National Taichung University of Science and Technology, Taichung, Taiwan. His interests are focused on the analysis and treatment of environmental pollutants. His team is currently working on the synthesis of various photocatalysts and investigating their photocatalytic abilities for removing organic pollutants in an aqueous solution.
Silver vanadates have received remarkable attention in recent years because of their stability, suitable band gaps, and relatively superior photocatalytic abilities. This study synthesizes silver vanadates and investigates their photocatalytic abilities for removing crystal violet (CV) and atrazine under visible-light irradiation. The silver vanadate photocatalysts with high photocatalytic performance are prepared by the hydrothermal method. The composition and morphologies of silver vanadates could be controlled by adjusting some growth parameters, including reaction pH, temperature, and the ratio of silver to vanadium in starting material. The as-prepared silver vanadates are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectra (DRS) and BET surface area analysis. It is demonstrated that AgVO3, Ag3VO4, and Ag4V2O7 can be selectively prepared through the hydrothermal method. Diffuse UV–Vis spectra show the three materials being the indirect semiconductors with optical bandgaps of 1.85–2.33 eV. Crystal violet and atrazine could be successfully degraded in the presence of silver vanadate catalyst under visible-light irradiation. The obtained results show complete degradation of crystal violet after 24 h, and over 97% of atrazine was degraded after 72 h of treatment. Liquid chromatography coupled with electrospray ionization mass spectrometry was applied to the analysis of the samples coming from the photocatalytic degradation of atrazine. The experimental results showed that there were nine intermediates existing in the photocatalytic reaction. Potential degradation pathways for atrazine were evaluated exhibiting three different degradation pathways including dechlorination–hydroxylation, alkylic-oxidation and de-alkylation. This is a study to show the superior activities of AgVO3, Ag3VO4, and Ag4V2O7 as a promising visible-light-responsive photocatalyst.
Chia-Fen Lee has her expertise in Polymer Materials and has interest in the study of the synthesis of polymer latex particles. She has synthesized various kinds of inorganic/polymer composite latex particles successfully for many years of experience in research. The conductive core-shell composite polymer particles are novel particles that can be used as fillers in anisotropic conductive films.
In this study, a modified electroless silver plating process was used to prepare the monodisperse Ag-coated polystyrene core-shell type particles (Ag-PS). Silver nuclei produced on polystyrene particles with an electroless plating method served as nucleation sites for the growth of silver shell. A scanning electron microscope (SEM) was used to observe the particle size and morphology of Ag-PS particles. The results showed that a dense, stable and uniform silver shell grew on the surface of PS particles to form the Ag-PS composite particles with the diameter of 3 μm. The bulk conductivity of the Ag-PS composites could achieve 2427 S/cm with only 36% silver content. According to the results, the Ag-PS composite particles have great potential to be used as fillers in anisotropic conductive films.