Enhanced Photoelectrocatalytic Activity of TiO 2 Nanowire Arrays via Copolymerized G-C 3 N 4 Hybridization

Photoelectrocatalytic (PEC) oxidation is an advanced technology that combines photocatalytic oxidation (PC) and electrolytic oxidation (EC). PEC activity can be greatly enhanced by the PC and EC synergy effect. In this work, novel copolymerized g-C 3 N 4 (denoted as CN x )/TiO 2 core-shell nanowire arrays were prepared by chemical vapor deposition. CN x were deposited on the surface of TiO 2 nanowire arrays using organic monomer 4,5-dicyanidazole and dicyandiamide as copolymerization precursor. TiO 2 nanowire arrays provide a direct and fast electron transfer path, while CN x is a visible light responsive material. After CN x deposition, the light response range of TiO 2 is broadened to 600 nm. The deposition of CN x shell effectively improves the PC efficiency and PEC efficiency of TiO 2 . Under visible light irradiation and 1 V bias potential, the rate constant k of PEC degradation of CN x /TiO 2 core-shell nanowire arrays is 0.0069 min −1 , which is 72% higher than that of pure TiO 2 nanowires. The built-in electric field formed in the interface between TiO 2 core and CN x shell would effectively promote photogenerated charge separation and PEC activity.