High-efficiency photocatalytic performance of Cr-SrTiO3-modified black TiO2 nanotube arrays

TiO2 nanotube arrays with high surface areas have grown in significance recently due to their excellent charge transport properties. However, they can only be excited by ultraviolet irradiation due to their wide band gap; this drawback has greatly limited their applicability to real-world devices. In this study, a series of heterostructured black-Cr-SrTiO3/TiO2 nanotube arrays with heterojunction structures were successfully fabricated using a hydrothermal method; this method simply involved controlling the hydrothermal reaction time used. The developed black-Cr-SrTiO3/TiO2 nanotube arrays exhibited superior charge separation and excellent visible light response performances. Furthermore, their visible light photocatalytic performance was significantly improved; this was attributed to the synergistic effect of coupling black TiO2 nanotube arrays with Cr-SrTiO3.