Table 5.
Summarising H2 sensing parameters of different graphene-based materials functionalised by noble metals and/or metal oxides and a pure CeO2 compared with this work.
| Base Material | Hybrid Material | Synthesis Method | H2 Conc. (ppm) | Temp. (°C) |
RH (%) | Response (%) | Response Time (s) | Recovery Time (s) |
|---|---|---|---|---|---|---|---|---|
| rGO [108] | WO3- Pd NPs | Hydrothermal | 100 | RT | - | 38 | 52 | 155 |
| rGO [109] | SnO2- Pd NPs | Microwave synthesis | 10,000 | RT | - | 3 | 7 | 6 |
| rGO [110] | NiO | Freeze drying | 10,000 | 50 | - | 0.64 | 28 | 142 |
| Graphene [111] | Pd NPs-SiO2 | Thermal CVD | 500 | RT | - | 4.1 | 213 | 600 |
| rGO [16] | Pd NPs | Wet chemistry | 5000 | 100 | 10 | 18.2 | 170 | 1440 |
| rGO [112] | Pd-Pt | Hummers’ method, Hydrothermal | 8000 | 25 | - | 0.52 | 300 | 600 |
| rGO [109] | Pt-SnO2 | Hummers’ method, Hydrothermal | 5000 | RT | - | 3 | 3 | 2 |
| CeO2 [39] | - | Wet chemistry | 100 | 400 | - | 2 | 420 | 660 |
| CeO2 [39] | Pd NPs | Wet chemistry | 100 | 350 | - | 19 | 60 | 360 |
| PDA/rGO (this work) | Pd NPs- 2D CeO2 | Wet chemistry | 6000 | 100 | 15 | 416 | 70 | 180 |