College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, Heilongjiang Province, 161000, China.
Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
Environ Pollut. 2019 May;248:516-525. doi: 10.1016/j.envpol.2019.02.052. Epub 2019 Feb 22.
High-efficiency nanophotocatalysts with large specific surface areas have a broad range of application prospects in the catalytic oxidation treatment of organic pollutants in wastewater. A chemical method was used to synthesize a TiO nanophotocatalyst with a mesoporous structure upon which a rare earth metal (Nd) was deposited, namely Nd-TiO-SBA-15 (NTS). The prepared NTS was characterized using X-ray diffractometry, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectrometry. The photocatalytic mechanism was explored using scavenger experiments with photoinduced carriers combined with total organic carbon and UV-Vis measurements. At the same time, the kinetic properties of the NTS photocatalytic degradation of methyl orange (MO) were evaluated. The results showed that the deposition of TiO nanoparticles on the surface of the SBA-15 molecular sieve did not change the mesoporous structure, and Nd was uniformly distributed on the surface of the nanophotocatalyst. The photogenerated holes of the NTS played an important role in the photocatalysis process. In addition, the synthesized NTS had good adaptability in the range of pH 2-10. At pH 4, the reaction rate constant (k) of the MO photocatalytic degradation by NTS was 0.011825 mg·(L·min), and the adsorption equilibrium constant (K) was 0.051359 L mg. In addition, the photocatalytic degradation rate of MO by NTS remained above 70%, even when the NTS was recycled four times. The NTS showed a good performance after recycling. This work provides a good foundation for the large-scale application of NTS.
具有大比表面积的高效纳米光催化剂在废水有机污染物催化氧化处理方面具有广泛的应用前景。本研究采用化学方法合成了一种具有介孔结构的负载稀土金属（Nd）的 TiO 纳米光催化剂，即 Nd-TiO-SBA-15（NTS）。采用 X 射线衍射、透射电子显微镜、拉曼光谱和 X 射线光电子能谱对所制备的 NTS 进行了表征。通过光生载流子与总有机碳的捕获实验结合 UV-Vis 测量，探讨了光催化机理。同时，评估了 NTS 对甲基橙（MO）的光催化降解动力学特性。结果表明，TiO 纳米颗粒沉积在 SBA-15 分子筛表面并未改变介孔结构，Nd 均匀分布在纳米光催化剂表面。NTS 的光生空穴在光催化过程中起着重要作用。此外，所合成的 NTS 在 pH 2-10 的范围内具有良好的适应性。在 pH 4 时，NTS 对 MO 的光催化降解反应速率常数（k）为 0.011825 mg·(L·min)，吸附平衡常数（K）为 0.051359 L mg。此外，即使 NTS 循环使用四次，MO 的光催化降解率仍保持在 70%以上。NTS 经回收后性能良好。这项工作为 NTS 的大规模应用提供了良好的基础。
