Aqueous photocatalytic oxidation (PCO) of amoxicillin (AMO), a beta-lactam antibiotic, was experimentally studied. Degussa P25 titanium dioxide and visible light-sensitive sol-gel synthesized carbon- and iron-doped titania were used as photocatalysts. The efficiency of PCO dependent on initial AMO concentration and pH was established. A number of organic and inorganic by-products were determined allowing construction of a possible reaction pathway. (C) 2010 Elsevier B.V. All rights reserved.