One-step synthesis of Ag nanoparticles/carbon dots/TiO2 nanotube arrays composite photocatalyst with enhanced photocatalytic activity

Abstract A silver nanoparticle (Ag NP)/carbon dot (CD)/TiO2 nanotube array (TNTA) composite with enhanced photocatalytic activity was solvothermally synthesized by a simple one-step method. TNTA comprised vertically arranged and highly ordered TiO2 nanotubes decorated by CDs and Ag NPs, with the amount of TNTA-supported Ag depending on the precursor (AgNO3) loading. Methylene blue photodegradation tests under visible and UV light were used to test the photocatalytic activity of the above composite and its recyclability, revealing that Ag/CDs/TNTA exhibited high durability and was more active than its individual components or two-component combinations. This behavior was ascribed to the suppressed recombination of photogenerated electron-hole pairs and the enhanced visible light absorption due to the surface plasmon resonance effect of Ag NPs and the photoelectrical properties of CDs. Thus, the developed photocatalyst was concluded to hold great promise for wastewater treatment and other environmental remediation applications.