Construction of g-C3N4/TiO2 nanotube arrays Z-scheme heterojunction to improve visible light catalytic activity

A simple anodic oxidation method was used to prepare TiO2 nanotubes (TNTs), and calcined at 500 degrees C with urea to prepare g-C3N4/TNTs (CN/TNTs) composites. The photocatalytic activity of TNTs was improved by constructing a Z-scheme transfer mechanism. The results show that 2 g CN/TNTs greatly improves the separation efficiency of electron-hole pairs and reduces its recombination efficiency, and the visible light absorption also undergoes a significant redshift. The degradation of rhodamine B can reach 96.3 %, and the degradation rate is 0.0195min(-1). The sample has good stability and can be used repeatedly without losing activity. In the CN/TNTs system, h(+), O-center dot(2)- and (OH)-O-center dot are active species.