Fabrication of CNTs and GP/AuGP modified TiO2 photocatalyst with two-channel electron conduction path for significantly enhanced photocatalytic activity

Abstract

A systematic study has been devoted to fabricate carbon nanotubes (CNTs), graphene (GP), and Au deposited graphene (AuGP) modified semiconductor photocatalysts with specific structures. We show a systematic investigation on improving the photocatalytic activity of TiO2 via a strategy of locating CNTs inside and GP/AuGP outside TiO2 nanoparticles, respectively. To enhance the interaction between TiO2 and CNTs/GP/AuGP, TiO2 was directly grown on the surface of CNTs and GP/AuGP was covered on the entire surface of CNTs modified TiO2 by the hydrothermal method. Au was used to fabricate a Schottky barrier on the TiO2 and Au interface, resulting more efficient electron transfer by the Au particles and GP. The CNTs@TiO2@GP and CNTs@TiO2@AuGP nanocomposites which show higher photoactivity than P25 prepared by this method is able to make efficient use of the electron conductivity of Au, GP, and CNTs, resulting in more efficient transfer of the photogenerated electrons and, hence, inhibit the photogenerated electron–hole pair recombination, thus the solar energy was more efficiently used to decompose the pollutants. This simple method is of great significance for the design and preparation of high active photocatalysts with specific structures for pollutant decomposition.