Nonradical oxidation has received wide attention in advanced oxidation processes for environmental remediation. Understanding the relationship between material characteristics and their ability to initiate nonradical oxidation processes is the key to better material design and performance. Herein, a novel titanium-based metal-organic framework MIL-125-Ti/H2O2 system was established to show a highly selective degradation efficacy toward tetracycline antibiotics. MIL-125-Ti with the abundance of TiO6 octahedra units was found to effectively activate H2O2 under dark conditions by forming an oxidative Ti-peroxo complex. The presence of the Ti-peroxo complex, confirmed by UV-visible spectrophotometer, fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy characterizations, showed superior degradation (> 95% removal rate) of oxytetracycline hydrochloride (OTC), doxycycline hydrochloride, chlortetracycline hydrochloride, and tetracycline. Density functional theory calculations were performed to assist the elucidation on the mechanism of H2O2 activation and antibiotics degradation. The MIL-125-Ti/H2O2 system was highly resistant to halogens and background organics, and could well maintain its original catalytic activity in actual water matrices. It retained the ability to degrade 75% of OTC within ten test cycles. This study provides new insight into the nonradical oxidation process initiated by the unique Ti-peroxo complex of Ti-based MOF.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |