Study on the fabrication and photoelectrochemical performance of the F- doped Ti/Co3O4 electrodes with n-type semiconductor characteristics

Herein, the Ti/Co3O4 electrodes with n-type semiconductor characteristics were fabricated by a typical hydrothermal process using F- ion as dopant, and their morphology control was also performed by tailoring the hydrothermal temperature. The F- doped Ti/Co3O4 electrodes could be used as photoanode to degrade anthraquinone dye (reactive Brilliant Blue KN-R), and showed excellent photoelectrocatalytic (PEC) activity. It is proposed that the fast ions and electron transportation, high oxygen evolution potential, lower resistance, large active area, and good electrolyte infiltration are responsible for the improved PEC activity of the F- doped Ti/Co3O4 system. Nevertheless, the F- doped Ti/Co3O4 electrode with divergent flower-like structure composed of needle nanowires exhibited highest PEC activity than that of other electrodes. It is noteworthy that the presence of electrostatic anti-barrier arises from an ohmic contact between the metal (Ti) and the semiconductor (Co3O4) is also an important factor for the higher PEC activity of the F- doped Ti/Co3O4 electrodes. The work provides unique insight into the design of Co3O4 photoanode from a perspective of tailoring the ion doping and morphology.