Gold nanoparticles in different proportions (0.5 and 1 %) have been grafted at the surface of a SiO2@g-C3N4 2 @g-C 3 N 4 nanotube-based composite (SiO2 2 nanotubes obtained from halloysite clay) and also g-C3N4 3 N 4 (for comparison purposes) to test their degradation capacity over the antibiotic amoxicillin proving that the introduction of these nanoparticles on the catalyst modifies the degradation mechanism followed by the pollutant. Results obtained show that the introduction of the appropriate percentage of gold NPs in the composite improves amoxicillin degradation efficiency and establish a direct correlation between the presence of gold NPs and the production of & sdot;O2 2- .