▎ 摘　　要

Graphene quantum dots sensitized TiO2 nanotube arrays (GQDs/TNAs) are fabricated via a modified electrophoretic deposition (MEPD) method, in which TNAs were pretreated by silane coupling agent. The influences of GQDs on the morphology, optical property and photocathodic protection performance of the hybrid GQDs/TNAs were investigated. By varying the time of MEPD, appropriate quantity of GQDs can be well attached to the inner walls and tube entrance of TNAs. Compared with the bare TNAs and GQDs/TNAs prepared by impregnation-precipitation and conventional EPD method, the GQDs/TNAs acquired at 15 min exhibits excellent visible-light response and enhanced photocathodic protection of the coupled 304 stainless steel. A higher photocurrent density of 800 mu A cm(-2) is achieved and the open-circuit potential shifts to a more negative value of 740 mV under white-light irradiation. The improved performance is attributed to GQDs, which is not only a green photosensitizer, but also a superb mediator for fast separation and transfer of the photogenerated charge.