The photoelectrocatalytic (PEC) process has attracted much attention in the field of the decontamination of drinking water and wastewater due to its environmental friendliness and considerable efficiency. As a promising class of PEC materials, Au/TiO2 has been focused by researchers for a long time. Nevertheless, it is still difficult to synthesize uniform Au/TiO2 composites without the use of surface ligands, which may hinder the understanding of their intrinsic PEC properties. In this work, ligand-free Au/highly ordered TiO2 nanotubes (Au/hoTiO(2) NTs) with high homogeneity were prepared successfully by carefully controlling the synthesis conditions. The physical and chemical properties of Au/hoTiO(2) NTs with different Au contents were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy, life-time of photogenerated electrons, decolorization of methyl orange (MO), and photocurrent. By comparing the influence of different trapping agents, the decolorization mechanism of MO is also discussed. This work may cast light on the understanding of the inherent properties of Au/TiO2 composites.