Tuning the size of aluminum oxide nanoparticles synthesized by laser ablation in water using physical and chemical approaches

► Al2O3 NPs size depends on laser power, focus condition, target inclination, and solution pH. ► Decreasing fluence with tightly focus condition decreases average size. ► Target inclination results a decrease in NPs size. ► Smaller particle was obtained at solution pH greatly above or below iso-electric point. ► Smallest average size was observed at pH = 11 with target inclined.