TiO2 nanotube and Au-modified TiO2 nanotube were prepared to evaluate tube effect.
Tubular morphology of TiO2 nanotube is kept after Au modification.
Tubular morphology of TiO2 nanotube plays a key role in enhancing NDMA degradation.
Tubular TiO2 initiates new NDMA photocatalytic path, generating DMA as main product.