Organic Semiconductor g‐C₃N₄ Modified TiO₂ Nanotube Arrays for Enhanced Photoelectrochemical Performance in Wastewater Treatment

Abstract g‐C 3 N 4 sensitized TiO 2 nanotube arrays (g‐C 3 N 4 /TNTs) were fabricated by using a simple solid sublimation and transition (SST) method using urea as precursor. The photoelectrochemical (PEC) performances were evaluated in this work. It is proposed that the g‐C 3 N 4 layer can play dual roles: surface sensitization and passivation of TNTs surface trap states to inhibit charge recombination. The g‐C 3 N 4 /TNTs exhibited significantly improved PEC performance compared with TNTs under blue light (460 nm) irradiation. The g‐C 3 N 4 /TNTs prepared from 3 g urea showed the highest photocurrent density of approximately 65 μA cm −2 , which is almost 10 times as high as that of TNTs. Furthermore, g‐C 3 N 4 /TNTs showed enhanced photoelectrocatalytic degradation of methylene blue (MB) under the blue light irradiation. The stable performance of degradation of MB in multicycle tests suggests that the hybrid g‐C 3 N 4 /TNT electrode could be used as a low‐cost photoelectrode material for wastewater treatment processes.