Nanostructured semiconductors are widely studied materials due to their wide range of potential applications, such as solar energy conversion. In the latter, a determining characteristic for semiconductors is the generated photocurrent, which is greatly influenced by the synthetic route and subsequent treatments. In this work, we present an in-situ potentiostatic and potentiodynamic approach to modify the photoelectrocatalytic properties of nanostructured TiO₂ electrodes. The effect of the morphology was studied by comparing a nanotubular and nanorod particulate TiO₂. A potentiodynamic (cyclic voltammetry) and potentiostatic (differential pulsed amperometry) were used to modify the electrodes in 0.5 M H₂SO₄. The photogenerated charge carriers separation was studied by CV, LSV and CA. Self-doping can tune the electronic and band structures of semiconductor photocatalysts like binary metal oxides. Thus, a change in the capacitance was observed after the reductive self-doping (SD) treatment that was studied by recording Mott-Schottky plots. The morphological, structural, and optical properties were characterized by SEM, XRD/Rietveld refining, XPS, respectively. The observed behaviors from electrochemical measurements suggested that morphology has an important in the capacitive properties. In the meantime, nanorod reacted quickly to light. Experimental results confirmed that self-doping could change the electronic structures to intrinsically improve the optical absorption property and charge transfer ability, thus enhancing the photocatalytic activity of semiconductors. This successful band structure tailoring example of semiconductors suggests the electrochemical treatments represent a facile and systematic technique to be general to develop novel visible light driven photoelectrocatalysts with enhanced performances.