Influence of the concentration of reducing agent on gold nanoparticles decorated reduced graphene oxide and its ammonia sensing performance

Gold nanoparticles decorated reduced graphene oxide were synthesized with various concentrations of ascorbic acid. Phase structure and the variation in particle size were analysed by XRD studies and SEM image, respectively. The extent of reduction in graphene oxide was analysed by different techniques. Then the sensor was fabricated by simple drop casting method on a glass and the electrical contacts were provided by silver electrodes. The electrical conductivity of the films was measured by I–V measurements. Electrochemical impedance spectroscopy was employed to monitor the charge transfer at the interface of electrode and the sample. Finally the ammonia sensing of the fabricated films was studied by chemiresisitive method and the results are compared.