Recyclable and reusable direct Z-scheme heterojunction CeO2/TiO2 nanotube arrays for photocatalytic water disinfection

Compared with the powder photocatalysts, the substrate photocatalysts are more practical in water disinfection because of their specific properties such as easy in recovery and high reusability. However, the low sterilization efficiency of substrate photocatalysts limit its further applications. Here, we prepared a binary composite direct Z-scheme heterojunction CeO2/TiO2 nanotube arrays (CeO2/TiO2 NTAs) to improve the photocatalytic disinfection performance. The heterojunction realized the spatial separation between the oxidation site and the reduction site under light irradiation. Consequently, it was favorable to produce ROS (·O2−, ·OH, 1O2) and showed a good antibacterial effect on both Gram-positive and negative bacteria (98.8 %). In addition, the results of the cyclic sterilization experiment showed that the sterilization efficiency of the CeO2/TiO2 NTAs still reached 98.3 % after 3 times of recycling and reuse. Furthermore, the material still maintains a good sterilization effect and recovery performance in practical applications.