speciesengineeringandcharacterizationsofdefectsintio2basedphotocatalyst

Light absorption, charge separation and surface reaction are considered as the main processes of photocatalysis on one semiconductor, and all of them are demonstrated to be related to the defect states of photocatalysts. This paper will choose TiO2 as model photocatalyst to introduce some basic concepts and strategies related to defects and methods developed to characterize defects in the past decades. Meanwhile, such strategies as hydrogenation and metal/nonmetal doping into TiO2 will be introduced to extend utilization of solar spectrum and/or to provide active sites. On the contrary, the unfavorable effect of defects such as acting as recombination centers of photogenerated carriers will also be introduced. Some typical methods to characterize the properties of defects are summarized, which contain electron paramagnetic resonance (EPR), photoluminescence technique (PL), positron annihilation spectroscopy (PAS), and so on. We do hope that this review will make a revealing effect on understanding to the functions of defects as well as construction of efficient photocatalytic systems in the future. (C) 2017 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved