Enhanced photocatalytic performance of Ag nanoparticle–TiO2−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 H2/N2. 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.