EXAFS Study on Disorder in Microstructure of Amorphous Mesoporous Titania with Large Surface Areas
Bibliographic record
Abstract
The mesoporous titania prepared by templating with hexadecylamine has an amorphous nature with a narrow pore size distribution centered at 2.8 nm and a Brunauer–Emmett–Teller (BET) surface area of 1230 m 2 g −1 . The extremely large surface area implies that most of the atoms are exposed at the surface. XAFS spectroscopy was applied to investigate the microstructure of mesoporous titania. The EXAFS function, k 3 χ( k ), was considerably different from that of anatase. The amplitude decreased significantly in the large k region, suggesting large static and thermal disorders of the Ti-Ti bond. The third peak in the radial distribution function, which appeared at 3.4 Å in anatase and was attributed to the Ti atoms at the next nearest neighbouring site, was hardly observed in the Fourier transform of mesoporous titania. A comparison of the spectra at different temperatures revealed that the temperature dependence of the Debye–Waller factor for the Ti-Ti bond was significant. σ 2 was plotted against temperature and the effective surface Debye temperature of mesoporous titania was calculated to be 365 K. This is significantly lower than for the bulk titania crystals, 520 and 530 K for anatase and rutile, respectively.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".