Synthesis of Ag-/Graphene Aerogel Composite for Removal of Methyl Orange

In this study, silver-titanium dioxide/graphene aerogel (Ag-TiO2/GA-ATG) was synthesized via chemical reduction using ethylene diamine (EDA). The effects of reductant doses on the formation of the three-dimensional structure and the photocatalytic degradation efficiency of ATG were evaluated with five different volumes (20, 30, 40, 50, and 60 mu L), corresponding to the ATG1, ATG2, ATG3, and ATG4, respectively. The results showed that 40 mu L of EDA was the suitable condition for the formation of ATG three-dimensional structure. Characterizations revealed that ATG3 was successfully synthesized with distinctive peaks of Ag and TiO2 in the X-ray diffraction patterns whilst scanning electron microscope and high resolution transmission electron microscope images showed a porous structure, silver nanoparticles and TiO2 with an average size of 10-25 nm were uniformly distributed on the graphene surface. Furthermore, ATG3 possessed the highest photocatalytic capability to deteriorate methyl orange with an efficiency of up to 99.53% with a catalyst dose of 0.3 mg/mL, superior compared to those of TiO2 and TiO2/GA. The radicals scavenging experiments elucidated O-center dot(2) to majorly contribute to the photodegradation process. Moreover, ATG3 showed high recyclability, which retains 80% of yield even after 10 cycles. Those findings proved that ATG has high potential in the environmental remediation field.