Zhu Yongfa

Elimination of Bisphenol A from Water via Graphene Oxide Adsorption

The elimination of bisphenol A(BPA) from aqueous solution by adsorption on graphene oxide(GO) was investigated.The maximum adsorption capacity(q m) of GO for BPA estimated from the Langmuir isotherm was 87.80 mg·g-1 at 25 ℃.The required contact time to reach adsorption equilibrium was about 30 min,which was much shorter than that of activated carbon.The adsorption kinetics and isotherm data fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm,respectively.Neutral pH and low solution temperature were favorable for adsorption,whereas the presence of NaCl in the solution was unfavorable.The GO had good recyclability and could be reused several times with a slight decline in adsorption ability.Both hydrogen bonding and π-π interaction were thought to be responsible for the adsorption of BPA on GO.The excellent adsorption capacity and high adsorption rate of GO result from its sheet-like structure and the abundant oxygen-containing groups on its surface.Although q m of GO for BPA is lower than that of graphene,GO has the benefits of large scale production,a hydrophilic surface with plenty of oxygen-containing groups,and good dispersion in water.Therefore,GO can be regarded as a good potential adsorbent for water treatment.

Controllable Synthesis and Photocatalytic Performance of Bismuth Phosphate Nanorods

BiPO4 nanorods with controlled morphologies were fabricated using a hydrothermal method. The photocatalytic activity of the BiPO4 nanorods was investigated by their ability to degrade methylene blue (MB). The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectroscopy (DRS). It was found that glycerol content, reaction time and temperature, and concentration of precursor influenced the morphology and structure of the product. The glycerol content and concentration of precursor mainly influence the morphology of the product. As the glycerol content increases, the aspect ratio first increases, and then decreases. The aspect ratio of the product increases and the size decreases as the concentration of precursor is lowered. When the reaction time is short, the crystallinity of the product is poor, and it forms a hexagonal phase. Hexagonal BiPO4 transforms into the monoclinic product when the reaction time is longer. The optimal temperature for crystal formation was found to be 160 °C. The results show that BiPO4 nanorods possess excellent photocatalytic activity under ultraviolet light. The photocatalytic activity of BiPO4 increased with an increase of aspect ratio and decrease of particle size. The crystallinity of the product has a significant influence on its photocatalytic activity. BiPO4 with higher crystallinity has higher photocatalytic activity, and monoclinic BiPO4 has higher photocatalytic activity than hexagonal BiPO4. [Article] doi: 10.3866/PKU.WHXB201112232 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2012, 28 (3), 654-660 March Received: September 15, 2011; Revised: December 12, 2011; Published on Web: December 23, 2011. ∗Corresponding author. Email: zhuyf@tsinghua.edu.cn; Tel/Fax: +86-10-62787601. The project was supported by the National Natural Science Foundation of China (20925725, 50972070, 51102150) and National Key Basic Research Program of China (973) (2007CB613303). 国家自然科学基金(20925725, 50972070, 51102150)及国家重点基础研究发展规划项目(973) (2007CB613303)资助 C Editorial office of Acta Physico-Chimica Sinica 654 刘艳芳等:磷酸铋纳米棒的可控合成及其光催化性能 No.3

Cataluminescence Performance on Catalysts of Graphene Supported Platinum

Platinum nanoparticles supported by graphene were prepared by the colloid deposition process. The effects of particle size and loading amount of platinum particles on the cataluminescence (CTL) properties of CO have been investigated. The CTL properties and some analysis characteristics of the catalyst on other gas phase systems were explored. The results show that the Pt nanoparticles are well distributed on graphene and a faster catalytic reaction rate is apparent. The smaller particles lead to a higher CTL intensity. When the volume concentration of CO in air is below 40% (渍, volume fraction) the CTL intensity is proportional to the concentration of CO for all the catalysts (0.4%-1.6% (w, mass fraction) Pt). Among them, the catalyst containing 0.8% Pt was found to be the best. However, by increasing the CO concentration the CTL intensity of the catalysts with a low Pt loading (0.4%, 0.8%) decreased while the highly loaded (1.2%, 1.6%) catalysts continued to increase their intensity. Moreover, a higher Pt loading led to a higher CTL intensity. Under certain conditions the catalyst shows good CTL performance for CO oxidation, and ether, methanol as well as toluene show different degrees of response. No response was obtained for carbon dioxide, formaldehyde, glutaraldehyde, acetone, ethyl acetate, chloroform, and water vapor.

Preparation of Tio2—Al2O3 by Impregnation with TiCl4—CCl4

Catalyst carrier TiO2—Al2O3 was prepared through impregnation γ—Al2O3 with non—aqueous solution of TiCl4 (e.g. carbon tetrachloride or acetone as solvent), followed by calcination at 550°C for 24 h. Series of TiO2—Al2O3 samples with various TiO2 loadings have been characterized by XRD, XPS, TEM and HEED techniques. The maximum dispersion capacities for TiO2 on γ—Al2O3 measured by XRD and XPS are 0.12g TiO2/g γ—Al2O3 and 0.11g TiO2/g γ—Al2O3, respectively. It was also verified by TEM and HEED techniques. This value illustrates that TiO2 disperse on the surface of γ—Al2O3 as a submonolayer and the observed monolayer coverage for TiO2 on γ—Al2O3 is 58% as compared with a close—packed monolayer model.