The search for a simple method to bestow trititanate nanotubes with visible-light activity for applications as solar-driven photocatalysts remains a challenging task. Here, we report that self-assembled surface modification by dopamine imparted trititanate nanotubes (TiNT) with stable, recyclable photocatalytic activity under UV and visible-light illumination. The controlled surface modification shifted the absorption onset into the visible region. These dopamine-modified trititanate nanotubes are expected to have applications in water treatment and in pollutant degradation.