Table 2. Modulated properties of photochromic carbon-based nanomaterials.
| Function | Composition | Modulation range | References |
|---|---|---|---|
| Dipole moment | Azobenzene/CNTs | From 9 to 6 Debye | 90 |
| Spiropyran/CNTs | A change up to 24.1 Debye | 91 | |
| Azobenzene/mechanical exfoliated graphene | From 9 to 6 Debye | 92 | |
| Azobenzene—chemically rGO | A change up to 3 Debye | 97 | |
| Spiropyran/chemically rGO | From 4 to 20 Debye | 95 | |
| Current change | Dithienylethene-CNTs | Ion/Ioff ratio >105 | 82 |
| Au/Azobenzene/mechanical exfoliated graphene | Ion/Ioff ratio of ∼100 | 87 | |
| Azobenzene-graphene | Ion/Ioff ratio of >100 (pH change) | 84 | |
| Au/dihydroazulene/thermally rGO | Average Ion/Ioff ratio of ∼5–7 | 85 | |
| Charge transfer/separation | Dithienylethene-porphyrin-fullerene | Photoinduced electron transfer (25 ps) to singlet-singlet energy transfer (2.3 ps) | 73 |
| Azobenzene-fullerene-porphyrin | Photo-induced intramolecular charge separation much faster than photo-isomerization | 75 | |
| Dihydroindolizine-porphyrin-fullerene | Quantum yield of electron transfer from 82 to 27% | 76 | |
| Dithienylethene-fullerene- tetrathiafulvalene | Reduced charge-separated state lifetime (from open to closed form) | 78 | |
| Charge transport | Spiropyran/chemically rGO | Hole mobility from 2.9 to 2.2 cm2 V−1 s−1, electron mobility remains almost constant at 2.6 cm2 V−1 s−1 | 95 |
| Spiropyran/graphene grown by chemical vapour deposition | Hole and electron mobility from 508.8 to 392.4, and from 428.4 to 301.2 cm2 V−1 s−1, respectively | 94 | |
| Azobenzene/mechanical exfoliated graphene | Charge carrier concentration from ∼5 × 1013 to ∼4 × 1013 cm−2 (2.8 × 1012 cm−2 for the other method) | 93 | |
| Azobenzene/mechanical exfoliated graphene | Hole Concentrations from 4.3 × 1012 to 3.5 × 1012 cm−2 | 92 | |
| Magnetism | Azobenzene/graphene | 0.8 μB (E)0.0 μB (Z) | 71 |
| Photoconductivity | Hexabenzocoronene-Dithienylethene | 4.9 × 10−3 cm2V−1 s−1 (closed form)9.6 × 10−4 cm2V−1 s−1 (open form) | 72 |
| Fluorescence | Carbon nanodots-spiropyran | 5 times change in intensity between closed and open form | 55 |
| Carbon nanodots-spiropyran polymer | Reversible switching between blue-green and red | 68 | |
| Dispersibility | Dendritic azobenzene/CNTs | Bundling–debundling | 34 |
| Morphology | Azobenzene-fullerene | Tunable 1D, 2D, 3D nanostructures | 70 |
| Azo-polymer/mechanical exfoliated multilayer graphene | Internal pressure exceeding 1 GPa | 118 |
CNT, carbon nanotube; rGO, reduced graphene oxide (the reduction can be done chemically, electrochemically or thermally and so on); 1D, one dimensional; 2D, two dimensional; 3D, three dimensional.