Gas sensing applications of multilayer graphene grown on Co-Ni/Al_{2O_{3 substrate by chemical vapour deposition

The gas sensing applications of multilayer graphene (MLG) films have been investigated in this study. The MLG was synthesised by chemical vapour deposition (CVD) over Co-Ni/Al2O3 substrate. The gas sensing experiment was performed by measuring resistance across the MLG film at different times while passing ammonia, hydrogen and, methane through. The MLG-based sensor was exposed to different concentrations of the gases for a period of 15 min at a fixed voltage of 1.5 V. When different gases were introduced to the test chamber at a steady flowrate, the resistance increased and reached a saturation level. The findings showed that the MLG-based sensor device was most sensitive to NH3 and H2 gases whereas it displayed least sensitivity to CH4 gas. This study has demonstrated the suitability of the MLG as a material that can be employed as a sensor device for gas sensing applications selective to NH3 and H2.