Table 1.
Parameters of the dry HGO and BGO powders and membranes.
| GO Material | Method of the Membrane Preparation | d (001). Å a (±0.3) |
C/O. b (±0.2) |
P20 (±0.01) |
|---|---|---|---|---|
| HGO (9:1) | 7.5 | 2.5 | ||
| mHGO (9:1) | Evaporation | 7.7 | 2.5 | |
| mHGO (9:1) | Vacuum filtration | 7.8 | 2.5 | 0.33 (TEMPOL) |
| HGO (9:3) | 7.8 | 2.2 | ||
| mHGO (9:3) | Vacuum filtration | 7.8 | 2.7 | 0.35 (TEMPOL) 0.41 (A3) |
| HGO (9:1→9:3) | 7.3 | 2.3 | ||
| mHGO (9:1→9:3) | Vacuum filtration | 7.7 | 2.3 | 0.34 (TEMPOL) |
| HGO c [17] | 7.18 | 2.47 | ||
| mHGO [21] | Vacuum filtration | 7.7 | 2.49 | |
| mHGO [9.21] | Vacuum filtration | 7.57 | 2.81 | |
| BGO (1) | 6.0 | 3.3 | ||
| BGO (2) | 6.6 | 2.8 | ||
| mBGO (2) | Vacuum filtration (pH = 12) | 6.6 | 2.8 | 0.21 (A3) |
| mBGO (2) | Vacuum filtration (pH = 7) | 6.4 | 2.8 | ≈0 (A3) |
| BGO (3) | 7.0 | 2.5 | ||
| BGO [17] | 6.35 | 2.85 | ||
| mBGO(1) [21.22] | Vacuum filtration (pH = 12) |
3.84 d |
a Inter-plane distance, calculated from the position of d(001) peak; b XPS data; c The sample was purchased from ACS materials company and was additionally dried by the authors [19]; d This number “is consistent with possible reaction of some functional groups with the hydroxide ion and removal of this products by water” [23].