Au(III)-CTAB reduction by ascorbic acid: Preparation and characterization of gold nanoparticles

► Reduction of HAuCl4 to metallic gold by ascorbic acid proceeds through the formation of CTA-AuCl4 complex in presence of CTAB. ► Shape and position of surface resonance plasmon band depends on the experimental conditions, i.e., concentrations of HAuCl4, ascorbic acid and CTAB. ► Sub-, post- and dilution-micellar effects are accountable to the different morphology of gold nanoparticles.