TiO₂ nanotube arrays offer an exciting prospect as a photocatalytic material architecture due to the combined properties of high surface area, 1-D vectorial charge transfer, and reduced photogenerated charge recombination. However, the TiO₂ band gap □ 3.2 eV, limits light absorption to the UV region which contains but a small fraction of the solar spectrum energy. Graphene is known to effectively absorb visible light, and due to its high conductivity promote efficient charge transfer. Herein, we present a novel photocatalyst composed of TNTs sensitized with electrodeposited graphene quantum dots. The GQDs electrodeposition duration is varied to optimize photocatalytic performance of the graphene-TNT nanostructure, with properties investigated by transient photocurrent measurement, electrical impedance spectroscopy, methylene blue (MB) degradation, and photocatalytic conversion of CO₂ to CH₄.