Enhanced Visible‐Light Photoelectrocatalytic Activity of {001}TiO 2 Electrodes Assisted with Carbon Quantum Dots

Aiming at further developing the application of highly reactive {001}TiO 2 in photoelectrocatalytic oxidation, which is only limited by its response in UV light, carbon quantum dots (CQDs) are introduced to provide the excitation sources for {001}TiO 2 through upconversion from visible to UV light. The CQDs/{001}TiO 2 photoelectrode is prepared by loading the CQDs on truncated square pyramid‐shaped TiO 2 spheres exposed to high‐activity {001} facets, using a simple impregnation–drying method. The results indicate that the CQDs/{001}TiO 2 possess enhanced photoelectrocatalytic ability with an increased photocurrent of 12 mA cm −2 and photocurrent decay time of 1.75 s. Compared with pure {001}TiO 2 , the surface photochemical reaction resistance of CQDs/{001}TiO 2 decreases, whereas the number of photogenerated carriers increase greatly. This visible‐light photoelectrocatalytic activity results from the synergistic effect of CQDs and the {001} facet of anatase TiO 2 .