A facile strategy to synthesize Pd/TiO2 nanotube arrays with high visible light photocatalytic performance

Novel Pd/TiO2 nanotube arrays (Pd/TNTAs) were fabricated by introducing Pd nanoparticles onto TNTAs via a facile deposition-reduction method. Pd nanoparticles can uniformly distribute over the inner and outer surfaces of TiO2 nanotubes by controlling the Pd loading. The hybrid prepared by two deposition-reduction cycles (Pd/TNTAs-2) showed the best visible light absorption and the highest transient photocurrent density compared with the pure TNTAs and other Pd/TNTAs. The Pd/TNTAs-2 sample also showed the best photocatalytic activity and recyclability toward the degradation of Rhodamine B (RhB). As much as 99.7% of RhB could be removed over the Pd/TNTAs-2 film within 2h under visible light irradiation, which is about three times higher than that over P25 films. The enhancement is attributed to the surface plasmon resonance of Pd nanoparticles and the effective interaction between Pd nanoparticles and TiO2 nanotubes, which improves the charge transfer and reduces the recombination rate of the photogenerated electron-hole pairs.