New insights on the enhanced non-hydroxyl radical contribution under copper promoted TiO2/GO for the photodegradation of tetracycline hydrochloride
| Autor: | Ying Zhang, Sijia Qian, Bo Lai, Shengyan Pu, Peng Wang, Yingchen Bai |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
Chemistry Oxide 02 engineering and technology General Medicine 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences Catalysis law.invention chemistry.chemical_compound Adsorption Reaction rate constant law Photocatalysis Environmental Chemistry Hydroxyl radical 0210 nano-technology Photodegradation Electron paramagnetic resonance General Environmental Science |
| Zdroj: | Journal of Environmental Sciences. 100:99-109 |
| ISSN: | 1001-0742 |
| DOI: | 10.1016/j.jes.2020.06.039 |
| Popis: | TiO2/graphene oxide (GO) as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied. But its low photocatalytic efficiency is attributed to the high band gap energy which lead to low light utilization. Cu-TiO2/GO was synthesized via the impregnation methods to enhance the catalytic performance. The Cu-TiO2/GO reaction rate constant for photo-degradation of pollutants (tetracycline hydrochloride, TC) was about 1.4 times that of TiO2/GO. In 90 min, the removal ratio of Cu-TiO2/GO for TC was 98%, and the maximum degradation ratio occurred at pH 5. After five cycles, the removal ratio of Cu-TiO2/GO still exceeded 98%. UV–visible adsorption spectra of Cu-TiO2/GO showed that its band gap was narrower than TiO2/GO. Electron paramagnetic resonance (EPR) spectra test illustrated the generation rate of •O2− and •OH was higher in Cu-TiO2/GO system than TiO2/GO and TiO2 system. The contribution sequence of oxidative species was •O2− > holes (h+) > •OH in both TiO2/GO and Cu-TiO2/GO system. Interestingly, the contribution of •OH in Cu-TiO2/GO was less than that in TiO2/GO during the photo-degradation process. This phenomenon was attributed to the better adsorption performance of Cu-TiO2/GO which could reduce the accessibility of TC to •OH in liquid. The enhanced non‑hydroxyl radical contribution could be attributed to that the more other active species or sites on (nearby) the surface of Cu-TiO2/GO generated after doping Cu. These results provide a new perspective for the tradition metal-doped conventional catalysts to enhance the removal of organic pollutants in the environment. |
| Databáze: | OpenAIRE |
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