Electrochemical synthesis of co-doped RGO-Bi-TiO2 nanotube composite: Enhanced activity under visible light

Abstract

TiO2 nanotube (TNT) photocatalyst with enhanced visible-light activity was synthesized by co-doping with reduced graphene oxide (RGO) and bismuth (Bi). The RGO-Bi-TNTs composite was fabricated using three different approaches: one-step, two-step, and three-step electrochemical anodization. The synthesized catalyst was characterized by FE-SEM, XRD, AES, and PL. Co-doping optimum synthesis using three-step method accomplished 1.5 and 3.8-times higher photocatalytic activity than single-doping and undoped-TNTs, respectively under same conditions. RGO and Bi were favorable for separation of e(-) and h(+), which reduced recombination of charges. This result promoted the formation of OH radicals and increased photocatalytic efficiency of TNTs under visible light. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.