Enhanced photocatalytic performance of Ag nanoparticle-TiO_2-X nanotube arrays obtained by a predischarge-deposition method and calcination in H₂/N₂

In this study, Ag/TiO2-X nanotubes with oxygen defects were synthesized by a simple and controllable predischarge-electrodeposition method, and they were calcined in H-2/N-2. After Ag modification, the maximum transient photocurrent of TiO2 nanotubes increased by 22.4 times. In addition, compared with that of pure TiO2 nanotubes, the photocatalytic performance of the Ag/TiO2-X nanotubes for degradation of methylene blue and aqueous formaldehyde was enhanced by 6.9 and 3.5 times, respectively. There are two reasons for the strengthened photocatalytic performance of Ag/TiO2-X. One is the localized surface plasmon resonance effect of Ag nanoparticles, which effectively promotes the separation of photogenerated electron-hole pairs. The other is that the oxygen defects act as shallow donors and accelerate charge transfer at the interface. This work provides a research idea for fabricating nanocomposites applied in photoelectrochemical and photocatalytical fields.