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Titanium dioxide surface modified with both palladium and fluoride as an efficient photocatalyst for the degradation of urea
| Content Provider | Semantic Scholar |
|---|---|
| Author | Kim, Hyoung Il Kim, Ki-Tae Park, Sanghoon Kim, Wooyul Kim, Seungdo Kim, Jungwon |
| Copyright Year | 2019 |
| Abstract | Abstract TiO2 surface modified with both Pd nanoparticles and fluorides (F-TiO2/Pd) was prepared and applied as a photocatalyst in the degradation of urea. Various surface analysis techniques, including X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy, were used to verify the coexistence of Pd nanoparticles and fluorides on the surface of TiO2 in F-TiO2/Pd. F-TiO2/Pd showed a higher photocatalytic activity than those of bare TiO2 and single-component-modified TiO2 photocatalysts such as fluorinated TiO2 (F-TiO2) and Pd-loaded TiO2 (Pd/TiO2). The higher urea degradation efficiency of F-TiO2/Pd is ascribed to the enhanced production of hydroxyl radicals ( OH) by the synergistic action of the surface Pd and fluoride. Pd nanoparticles and fluorides facilitate the transfer of valence band holes (hvb+) and their reaction with water molecules, respectively, synergistically enhancing the production of OH. The photocatalytic activity of F-TiO2/Pd for the degradation of urea increased upon increasing the fraction of the fluorinated TiO2 surface, which is higher at higher fluoride concentrations and lower pH. Although Pt/TiO2 showed higher photocatalytic activity for the degradation of urea than those of Pd/TiO2 and Au/TiO2, the strong positive effect of fluoride complexation was only exhibited by Pd/TiO2 (a slight positive effect and a negative effect were observed for Au/TiO2 and Pt/TiO2, respectively). As a result, the degradation of urea proceeded more rapidly in a UV-irradiated suspension of F-TiO2/Pd than when any of other photocatalysts (i.e., bare TiO2, Pd/TiO2, F-TiO2, Au/TiO2, F-TiO2/Au, Pt/TiO2, and F-TiO2/Pt) were used under the same conditions. The first-order degradation rate constants (k) of urea depending on the type of TiO2 were as follows: 0.097 h−1 for bare TiO2, 0.158 h−1 for Pd/TiO2, 0.151 h−1 for F-TiO2, 0.351 h−1 for F-TiO2/Pd, 0.173 h−1 for Au/TiO2, 0.223 h−1 for F-TiO2/Au, 0.240 h−1 for Pt/TiO2, and 0.165 h−1 for F-TiO2/Pt, respectively. In addition, F-TiO2/Pd proved to be stable in repeated urea degradation cycles. |
| Starting Page | 580 |
| Ending Page | 587 |
| Page Count | 8 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.seppur.2018.07.058 |
| Alternate Webpage(s) | http://repository.kopri.re.kr/bitstream/201206/9661/1/2018-0112(2019).pdf |
| Alternate Webpage(s) | https://doi.org/10.1016/j.seppur.2018.07.058 |
| Volume Number | 209 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
