The photoelectrocatalytic removal of ammonia in water was investigated using highly ordered TiO2 nanotube arrays as a photoanode. The results showed that the removal efficiency of total ammonia nitrogen (TAN) was closely related to the bias potential applied on TiO2 nanotube photoanode. Even without an adjustment of pH, over 99% of TAN (initial concentration 0.145 mM) was removed in 120 min with a bias potential of 1.0V. It is important to note that the TAN could be directly oxidized into N-2 and NO3--N without accumulation of an intermediate product of NO2--N. Meanwhile, the presence of the chemical scavengers revealed that photogenerated holes were the main oxidative species for the TAN oxidation. This work highlights the potential application of photoelectrocatalysis in the field of aqueous ammonia elimination. (C) 2014 Elsevier B.V. All rights reserved.