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.
在这项工作中,阳离子或阴离子掺杂的
锐钛矿TiO2纳米颗粒是通过低温沉淀-胶化过程(L
TPPP)合成的,反应中使用了聚
乙烯亚胺(PEI)和聚(
钠-4-
苯磺酸盐)(PSS)。X射线衍射(XRD)图谱和高分辨率透射电子显微镜(HR
TEM)确认了
锐钛矿的晶相。通过ζ电位研究了所制备的TiO2、PEI-TiO2和PSS-TiO2纳米颗粒的电荷。结果表明,PEI-TiO2纳米颗粒的ζ电位可以从+39.47 mV调节至+95.46 mV,而PSS-TiO2纳米颗粒的ζ电位可以从−56.63 mV调节至−119.32 mV。与TiO2相比,PSS-TiO2表现出显著的
染料分子的吸附和降解,而PEI修饰的TiO2纳米颗粒显示出较低的光催化活性。这些带电纳米颗粒的光催化性能通过紫外-可见漫反射光谱(DRS)和光致发光(PL)光谱的结果得到阐明,显示PSS-TiO2纳米颗粒的电子-空穴对的复合速率低于TiO2和PEI-TiO2。