Uniform decoration of silver nanoparticle on exfoliated graphene oxide sheets and its ammonia gas detection

Silver nanoparticles (AgNP) decorated graphene oxide (GO) sheets were prepared by reducing AgNO3 with vitamin C in the presence of GO. Different molar concentration of AgNO3 played a significant role in the size of AgNP in GO. The synthesized AgNP-GO composites were characterized by powder X-ray diffraction, scanning electron microscopy, ultraviolet-visible-near infrared, Fourier transform infrared and micro Raman spectroscopy techniques. We demonstrated the fiber optic gas sensor using reduced graphene oxide (rGO) and AgNP-GO composites for 0-500 ppm ammonia vapor concentrations at 27 °C. Sensitivities of rGO, 0.1 M AgNP-GO and 0.6 M AgNP-GO composites coated fiber optic sensors were calculated as −0.08, −0.177, −0.12 counts/ppm respectively. The agglomeration of AgNP at 0.6 M concentration along with increased particle size significantly decreased the sensing performance.