Morphology optimization of CVD graphene decorated with Ag nanoparticles as ammonia sensor

- Hybrid of CVD graphene and Ag nanoparticles (NPs) with different morphology Ag NPs have been prepared.
- The effect of Ag NPs morphology as coverage and size on the ammonia sensing performance is investigated.
- Optimized Ag NPs morphology for excellent sensing performance has been obtained.
- The selectivity and stability of appropriate Ag NPs decorated graphene sensors also discussed.

Hybrids of graphene and metal nanoparticles (NPs) have been intensively studied to enhance gas sensing performance. There is a certain correlation between the morphology of decorated metal NPs and the sensing performance of the metal NPs/graphene hybrids sensors. The effect of Ag NPs coverage and size on the ammonia sensing performance is investigated via several interdigitated electrodes (IDEs) device structure. Maximum response was observed within optimized morphology when the Ag NPs coverage is between 3.5-5% and size 0.13-0.19 μm. In addition, the optimized Ag NPs/graphene hybrid sensors exhibited faster response, better selectivity and excellent stability. This work will make a critical contribution to gas sensing application using metal NPs/graphene hybrid sensor.