State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, PR China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2012;47(3):327-36. doi: 10.1080/10934529.2012.645775.
In the present study, photocatalytic Pb(II) reduction over TiO(2) and Ag/TiO(2) catalysts in the presence of formic acid was explored to eliminate Pb(II) pollution in water. Ag/TiO(2) catalysts were prepared by the photo-deposition method and characterized using UV-Vis diffuse reflectance spectra, X-ray reflection diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Ag deposition on TiO(2) led to enhanced photocatalytic Pb(II) reduction and the Ag/TiO(2) catalyst with a Ag loading amount of 0.99 wt.% exhibited the optimum photocatalytic activity. For Pb(II) reduction over Ag/TiO(2) with a Ag loading amount of 0.99 wt.%, initial Pb(II) reduction rate was found to be dependent on the initial concentrations of formic acid and Pb(II). Increasing initial Pb(II) concentration led to linearly increased initial Pb(II) reduction rate. At low formic acid concentration, in parallel, initial Pb(II) reduction rates increased with formic concentration, but remained nearly identical at high formic acid concentration. Solution pH impacted the photocatalytic Pb(II) reduction and after irradiation for 100 min Pb(II) was removed by 11.8%, 91.2% and 98.6% at pH of 0.8, 2.0 and 3.5, respectively, indicative of enhanced Pb(II) reduction with pH in the tested pH range. The results showed that Ag/TiO(2) displayed superior catalytic activity to TiO(2), highlighting the potential of using Ag/TiO(2) as a more effective catalyst for photocatalytic Pb(II) reduction.
在本研究中，探讨了在甲酸存在下，TiO2 和 Ag/TiO2 催化剂上的光催化 Pb(II)还原，以消除水中的 Pb(II)污染。Ag/TiO2 催化剂采用光沉积法制备，并通过紫外-可见漫反射光谱、X 射线反射衍射、透射电子显微镜和 X 射线光电子能谱进行了表征。Ag 沉积在 TiO2 上导致光催化 Pb(II)还原增强，Ag 负载量为 0.99wt.%的 Ag/TiO2 催化剂表现出最佳的光催化活性。对于 Ag 负载量为 0.99wt.%的 Ag/TiO2 上的 Pb(II)还原，初始 Pb(II)还原速率取决于初始甲酸和 Pb(II)浓度。增加初始 Pb(II)浓度导致初始 Pb(II)还原速率线性增加。在低甲酸浓度下，初始 Pb(II)还原速率与甲酸浓度平行增加，但在高甲酸浓度下几乎保持不变。溶液 pH 影响光催化 Pb(II)还原，在 100 min 照射后，pH 分别为 0.8、2.0 和 3.5 时，Pb(II)的去除率分别为 11.8%、91.2%和 98.6%，表明在测试的 pH 范围内，pH 升高可增强 Pb(II)还原。结果表明，Ag/TiO2 比 TiO2 具有更高的催化活性，突出了将 Ag/TiO2 用作更有效的光催化 Pb(II)还原催化剂的潜力。
