Binary composite MoS2/TiO2 nanotube arrays as a recyclable and efficient photocatalyst for solar water disinfection

Despite the development of advanced photocatalysts, the practical application of photocatalytic water disinfection is still under restrictions due to the low reusability of powder photocatalysts. In this paper, we synthesized the binary composite heterojunction photocatalyst MoS2/TiO2 nanotube arrays (MoS2/TiO2 NTAs), using anodic oxidation method and hydrothermal method. The water disinfection efficiency of MoS2/TiO2 NTAs under visible light irradiation against pathogenic bacteria was up to 98.5% and still reached 92.1% after 3 times recovering and recycling. The mechanism was proven to be the seriously damage of bacterial cell membrane caused by the ROS produced from MoS2/TiO2 NTAs photocatalyst under light irradiation. In addition, we analyzed the water sample changes after material recovery by ICP-MS, and found that there is no MoS2 nanosheet falling off. This result supported the recyclable effect of MoS2/TiO2 NTAs and avoided the nanoparticles remaining in the water as much as possible. Therefore, MoS2/TiO2 NTAs composites have great application prospects in water disinfection due to their excellent photocatalytic disinfection effect, recyclability and reusability.