Other than that, AgNPs reacts with phenol and form other phenolic derivatives such as quinone which is known to form covalent bonds with proteins, thus exhibiting adverse effects to humans . Silver nanoparticles need to be modified by metallic oxides like TiO2 [104] and ZnO to enhance its catalytic and photocatalytic degradation for the removal of phenol and its derivatives. If not combined with organic or inorganic materials the removal efficiency of phenol is reduced .