Functionalization of Au/TiO₂ Plasmonic Photocatalysts with Pd by Formation of a Core–Shell Structure for Effective Dechlorination of Chlorobenzene under Irradiation of Visible Light

Abstract

Gold (Au) nanoparticles supported on titania (TiO 2 ) and ceria have been applied to a visible-light-responding plasmonic photocatalyst and functionalization of Au/TiO 2 photocatalysts with cocatalysts were achieved by separate loading of Au nanoparticles and cocatalyst nanoparticles without alloying and nanoparticle coagulation. Here we report effectiveness of another functionalization by formation of a core− shell structure in photocatalytic reaction induced by SPR of Au/TiO 2 . Newly functionalized core−shell gold−palladium particles supported on TiO 2 (Au@Pd/TiO 2 ) were successfully prepared by using a two-step photodeposition method, and Au@Pd/TiO 2 with a shell thickness of 1.0 nm quantitatively converted chlorobenzene and 2-propanol to benzene and acetone under irradiation of visible light. Thickness control of the Pd shell was very important for both a satisfactory cocatalyst effect and absorption due to SPR of Au nanoparticles. The results of this study provide useful information for design of functionalization of plasmonic photocatalysts by formation of a core−shell structure.

Photo-reduced Cu/CuO nanoclusters on TiO2 nanotube arrays as highly efficient and reusable catalyst

“…SEM characterizations shown in Supplementary Fig. S5(a–c) confirm the successful decoration of Au, Ag and Pd nanoparticles on TiO 2 , revealing that this surfactant-free method is suitable for various metals28. Figure 6(a–c) show the time-dependent UV-vis absorption spectra of 4-NP reduction with Au-TiO 2 , Ag-TiO 2 and Pd-TiO 2 as catalyst, respectively.…”

“…In-situ surfactant-free photoreduction method was carried out for the decoration of “clean” Cu/CuO nanoclusters on top of the ordered TiO 2 NT arrays2728. First, different concentration of CuCl 2 aqueous (0.02 mM, 0.1 mM and 0.5 mM) contained 5 vol% ethanol were prepared and saturated with N 2 .…”

“…Herein, we fabricate Cu/CuO-TiO 2 catalyst by decorating non-noble Cu/CuO nanoclusters on highly ordered TiO 2 nanotube (NT) arrays through a surfactant-free photoreduction method2728. This novel catalyst exhibits several advantages in catalytic application: (1) cost-efficient.…”

Direct Photocatalysis for Organic Synthesis by Using Plasmonic‐Metal Nanoparticles Irradiated with Visible Light

“…As shown in Figure 28, plasmon-excited surface Au atoms promote the intraband transition of 6sp electrons. [79] Figure 27. Au-Pd core-shell nanoparticles catalyze chlorobenzene and 2propanol to benzene and acetone under visible-light irradiation.…”

Eco-Friendly Physical Activation Methods for Suzuki–Miyaura Reactions

“…This can be understood if we consider that the work function of Pd metal is 5.00 eV in a vacuum, which is larger than the work function of Ag metal, which is 4.30 eV in a vacuum. The amount of energy required to eject the electron determines the position of the Fermi level, suggesting that the position of the Fermi level of Pd is lower to that of Ag, making the electron transfer process achievable [165,166]. Activated Pd species can therefore accelerate the oxidative addition step, resulting in an increase in the intrinsic catalytic activity of palladium.…”