LAUSR

Abstract A composite Co 3 O 4 /Ag/TiO 2 nanotubes (NTs) electrode, that subsequently photo-reduction of Ag and thermal decomposition of Co 3 O 4 nanoparticles onto electrochemical anodized TiO 2 -NTs, was synthesized for enhancement of visible light photoelectrochemical (PEC) performance. The visible light response of Co 3 O 4 /Ag/TiO 2 -NTs with highest photocurrent of 0.54 mA/cm 2 was obtained under calcination temperature of 400 °C for Co 3 O 4 (311) crystal formation. The Co 3 O 4 /Ag/TiO 2 -NTs electrode provided a remarkable photoconversion efficiency of 0.18% at an on-set potential of 0.44 V which was twice than that of Co 3 O 4 /TiO 2 -NTs electrode (0.06%). The synergetic effect for degradation of nitrobenzene (NB) and reduction of Cr(VI) was studied to analyze the possible mechanism of Co 3 O 4 /Ag/TiO 2 -NTs. It was proposed that Ag nanoparticle acted as bridge transferred the photo-induced electrons from Co 3 O 4 to TiO 2 -NTs and then largely facilitated the electron-holes separation to enhance the PEC activity.