title: Low-temperature synthesis of anatase TiO2 nanoparticles with tunable surface charges for enhancing photocatalytic activity.
abstract: In this work, the positively or negatively charged anatase TiO2 nanoparticles were synthesized via a low temperature precipitation-peptization process (LTPPP) in the presence of poly(ethyleneimine) (PEI) and poly(sodium4- styrenesulfonate) (PSS). X-ray diffraction (XRD) pattern and high-resolution transmission electron microscope (HRTEM) confirmed the anatase crystalline phase. The charges of the prepared TiO2, PEI-TiO2 and PSS-TiO2 nanoparticles were investigated by zeta potentials. The results showed that the zeta potentials of PEI-TiO2 nanoparticles can be tuned from +39.47 mV to +95.46 mV, and that of PSS-TiO2 nanoparticles can be adjusted from -56.63 mV to -119.32 mV. In comparison with TiO2, PSS-TiO2 exhibited dramatic adsorption and degradation of dye molecules, while the PEI modified TiO2 nanoparticles showed lower photocatalytic activity. The photocatalytic performances of these charged nanoparticles were elucidated by the results of UV-vis diffuse reflectance spectra (DRS) and the photoluminescence (PL) spectra, which indicated that the PSS-TiO2 nanoparticles showed a lower recombination rate of electron-hole pairs than TiO2 and PEI-TiO2.
authors.affiliation: College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China; Beijing Key Laboratory for Green Catalysis and Separation, Beijing, PR China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China.
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Qin
authors.affiliation: College of Materials Science and Engineering, Beijing University of Technology, Beijing, China; Beijing Key Laboratory for Green Catalysis and Separation, Beijing, PR China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Guo
authors.affiliation: College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China.
authors.forename: Hanxiao
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China.
authors.forename: Guojun
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China; Beijing Key Laboratory for Green Catalysis and Separation, Beijing, PR China.
authors.forename: Shulan
authors.initials: S
authors.lastname: Ji
authors.affiliation: MIT, Elect. Res. Lab, Cambridge, Massachusetts, United States of America.
authors.forename: Tingying
authors.initials: T
authors.lastname: Zeng
mesh_terms: D002384:Catalysis; D003080:Cold Temperature; D004396:Coloring Agents / Q000302:isolation & purification*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010782:Photolysis; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; D011108:Polymers; D013451:Sulfonic Acids; C009495:titanium dioxide; D011094:Polyethyleneimine; D014025:Titanium; C077114:styrenesulfonic acid polymer