Radiation-Induced Formation of Chromium Oxide Nanoparticles: Role of Radical Scavengers on the Redox Kinetics and Particle Size
Alrehaily, LM; Joseph, JM; Wren, JC
| HERO ID | 3121519 |
|---|---|
| In Press | No |
| Year | 2015 |
| Title | Radiation-Induced Formation of Chromium Oxide Nanoparticles: Role of Radical Scavengers on the Redox Kinetics and Particle Size |
| Authors | Alrehaily, LM; Joseph, JM; Wren, JC |
| Journal | Journal of Physical Chemistry C |
| Volume | 119 |
| Issue | 28 |
| Page Numbers | 16321-16330 |
| Abstract | The formation of Cr2O3 nanopartides by gamma-irradiation of dichromate solutions was investigated in the presence of radical scavengers, tert-butyl alcohol, nitrous oxide, and dissolved oxygen. The concentrations of Cr-VI and Cr-III species and the chemical composition and sizes of particles that were formed were measured as a function of irradiation time. A mechanism is proposed that is consistent with the observed effects of scavengers on the kinetics of reduction of Cr-VI in solution to solid Cr-III and the final size of Cr2O3 nanopartides that are formed. The chromium reduction occurs in three stages: Stage I involves homogeneous aqueous reduction of Cr-VI(aq) to Cr-III(aq) followed by spontaneous condensation of Cr(OH)(3), providing nucleation sites onto which Cr-VI and Cr-III coprecipitate and form mixed Cr-VI/Cr-III oxide/hydroxide particles. In Stage II, the aqueous reduction of Cr-VI(aq) and Cr-III(aq) reaches steady state but the adsorption of Cr-VI continues, growing the mixed Cr-VI/Cr-III oxide/hydroxide particles. Stage 3 involves the solid-state conversion of Cr-VI and Cr-III, and the particles slowly convert from a mixed Cr-VI/Cr-III oxide/hydroxide to Cr(OH)(3) and then to Cr2O3. Adding a radical scavenger in solution affects the kinetics of particle formation and growth at different stages differently. This information can be used to tailor the final sizes of particles. |
| Doi | 10.1021/acs.jpcc.5b02540 |
| Wosid | WOS:000358337700060 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |