Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa.
Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa.
J Environ Manage. 2020 Apr 15;260:110145. doi: 10.1016/j.jenvman.2020.110145. Epub 2020 Jan 24.
A comparative photocatalytic degradation of 2-chlorophenol (2CP) in aqueous solution was investigated using pristine and Ag-doped semiconductor photocatalysts obtained from TiO, ZnO and ZnS. Varying percentages (1, 3 and 5%) of Ag nanoparticles were doped on the semiconductor photocatalysts via the sol-gel method. The pristine and Ag-doped photocatalysts were characterized using UV-Vis diffuse reflectance spectroscopy, photo-luminescence spectroscopy, X-Ray diffractometry, Fourier transform infrared spectroscopy and transmission electron microscopy; and these techniques confirmed the successful syntheses of the pristine and Ag-doped species. The photocatalytic activities of all species for the degradation of 2CP were carried in photo-reactor using UV irradiation intensity of 1.4 mW/cm for 150 min; and the effects of various operating parameters (such as catalyst loading, pH and 2CP initial concentrations) were studied. The results showed enhanced 2CP degradation in the Ag-doped species in comparison to the pristine species while alkaline pH region was most suitable for 2CP degradation especially at low concentration. Lower loadings of the photocatalysts were usually more effective for the 2CP degradation and the degradation trend in the TiO and ZnS species was 5% Ag-doped >3% Ag-doped >1% Ag-doped > Pristine, while it was 1% Ag-doped >3% Ag-doped >5% Ag-doped > Pristine in the ZnO. Thus, although the Ag doping enhanced 2CP by all semiconductor photocatalysts, the Ag-doped TiO was more effective than the ZnO and ZnS species.
采用溶胶-凝胶法在 TiO2、ZnO 和 ZnS 半导体光催化剂上掺杂不同质量分数（1%、3%和 5%）的 Ag 纳米粒子，制备得到了纯相和 Ag 掺杂的半导体光催化剂，用于研究 2-氯苯酚（2CP）在水溶液中的光催化降解性能。通过紫外-可见漫反射光谱、光致发光光谱、X 射线衍射、傅里叶变换红外光谱和透射电子显微镜对纯相和 Ag 掺杂的光催化剂进行了表征，这些技术证实了纯相和 Ag 掺杂物种的成功合成。在光反应器中，采用 1.4 mW/cm2 的紫外光辐射强度，对所有物种进行 150 min 的光催化降解 2CP 实验，并研究了各种操作参数（如催化剂负载量、pH 和 2CP 初始浓度）的影响。结果表明，与纯相相比，Ag 掺杂物种的 2CP 降解率更高，而在碱性 pH 区域，2CP 降解率最高，特别是在低浓度时。较低的光催化剂负载量通常更有利于 2CP 的降解，在 TiO2 和 ZnS 物种中，降解趋势为 5%Ag 掺杂>3%Ag 掺杂>1%Ag 掺杂>纯相，而在 ZnO 中，降解趋势为 1%Ag 掺杂>3%Ag 掺杂>5%Ag 掺杂>纯相。因此，虽然 Ag 掺杂增强了所有半导体光催化剂对 2CP 的降解能力，但 Ag 掺杂的 TiO2 比 ZnO 和 ZnS 物种更有效。
