| Functional group | Reference frequency range (cm−1) [35] [36] [39] - [44] | Observed IR frequency (cm−1) for iron oxide | IR frequency (cm−1) for MoFe3O4 | Peak shift (cm−1) |
| OH stretching | 3700 - 3500 | 3668.3 | 3664.7 | 3.6 |
| OH (Alcohol) | 3400 - 2400 | 2903.3 2975.8 | 2899.7 2983.3 | 3.6 −7.5 |
| OH bend (Carboxylic acid) | 1440 - 1400 | - | 1438.7 1406 | - |
| H-O-H (Adsorbed water) | 1652 - 1429 | 1442.3; 1620 | 1438.7 - | 3.6 |
| CO stretching (Carboxylic acid) | 1320 - 1210 | - | 1243 | - |
| OH stretching vibration | 1092 - 1060 | 1068.9 | 1068.9 | 0 |
| CO stretching (Alcohol) | 1260 - 1000 | 1239.3 | 1243 | −3.7 |
| Alkenes (CH bend) | ~890 | 889.49 | 869.49 | 20 |
| Aromatics (CH bend) | ~880 | 889.49 | 869.49 | 20 |
| Fe-O | 588 - 535 | 564.95 | 543.2 | 21.75 |