Energy-absorption-based explanation of the TiO2/C photocatalytic activity enhancement mechanism

The reason for the significant photocatalytic activity improvement exhibited by TiO2/C is currently a topic of great research interest, and many different explanations of this phenomenon have been proposed. In this paper, we provide a new explanation of this enhancement mechanism that takes into consideration the energy absorption characteristics of TiO2/C. First, we determined the relationship among the wavelength of the incident light, the TiO2 particle radius, and the energy of the scattered light based on the results of Mie analysis. Then the energy absorption characteristics inside TiO2/C were observed using the finite-difference time-domain method. The calculated results revealed that light can be scattered by TiO2 particles during the light transfer process, causing the amorphous C near the TiO2 particles to absorb more energy than the C in other regions. This phenomenon can enable the amorphous C near the TiO2 particles to produce photoelectrons, which can subsequently migrate to the conduction band of TiO2, resulting in enhanced photocatalytic activity. (C) 2017 Elsevier Inc. All rights reserved.