One-step electrochemical synthesis of graphene oxide-TiO2 nanotubes for improved visible light activity

Abstract

Graphene oxide (GO)-TiO2 nanotubes (TNTs) were synthesized by one-step anodization. An as-prepared photocatalyst was characterized by FE-SEM, XRD, AES, PL, and UV-Vis DRS. To determine the effect of synthesis conditions on organics degradation, we prepared the catalyst with different GO concentrations, anodization voltages, and times. Optimum synthesis conditions were GO concentration 0.25 g L-1 and anodization at 48 V for 2 h. Compared with TNTs, GO-TNTs showed a 3.6-fold increase in photocatalytic efficiency under visible light. Recycling was performed to investigate the stability of a GO-TNT catalyst. GO-TNTs is favorable for the separation of charges (e(-)/h(+)), promotion of the formation of OH center dot, h(+), and superoxides, which degrade organics.