Table 1.
Structural and textural properties of the studied samples (as obtained by X‐Ray Diffraction and N2 isotherms at −196 °C); band‐gap energy values (as obtained by DR‐UV/Vis spectroscopy) and pH at the isoelectric point (pHIEP, as obtained by ζ‐potential measurement).
|
Sample |
Crystallite size (nm)a |
QPA results (wt %)b |
SSA (m2 g−1)c |
Band‐gap energy (Eg, eV)d,e,f |
pHIEP |
|---|---|---|---|---|---|
|
Total Pore Volume (cm3 g−1) | |||||
|
P25 |
19±3 (A) 23±4 (R) |
88.8 (A) 11.2 (R) |
74 |
3.30d |
6.2–6.9g |
|
3.03e | |||||
|
0.10 |
3.51f |
||||
|
M‐TiO2 |
12.4±1.3 (A) |
100 (A) |
150 |
3.25d |
2.37 |
|
3.15e | |||||
|
0.28 |
3.35f |
||||
|
RM‐TiO2 |
9.3±0.7 (A) 5.8±1.7 (B) |
91.1 (A) 8.9 (B) |
70 |
3.17d |
3.56 |
|
3.07e | |||||
|
0.09 |
3.29f |
||||
|
TF‐TiO2‐200 |
5.5±0.6 (A) 3.8±0.4 (B) |
78.0 (A) 22.0 (B) |
210 |
3.37d |
2.77 |
|
3.20e | |||||
|
0.31 |
3.57f |
||||
|
TF‐TiO2‐600 |
39.0±5.5 (A) 16.8±3.6 (B) 52.1±8.1 (R) |
81.6 (A) 9.3 (B) 9.1 (R) |
31 |
3.22d |
2.36 |
|
3.02e | |||||
|
0.09 |
3.36f |
a As obtained by applying the Williamson‐Hall method; b as obtained by Rietveld refinement; c as obtained by applying the BET method; d as obtained by linear extrapolation of the absorption edge; e as obtained by applying the Tauc's plot method for indirect band‐gap semiconductor (F(R)*hν)1/2; f as obtained by applying the Tauc's plot method for direct band‐gap semiconductor (F(R)*hν)2; g as reported in the literature for P25 NPs with average size in the 20–40 nm range and from ref.32