Programmed synthesis of Pd@hTiO₂hollow core–shell nanospheres as an efficient and reusable catalyst for the reduction of p-nitrophenol

Abstract

Here, we report a facile synthesis approach to obtain a Pd@hTiO 2 hollow mesoporous nanocomposite composed of tiny Pd nanoparticles cores encapsulated within hollow TiO 2 mesoporous shells. The core-shell strategy efficiently prevents the aggregation of Pd NPs (Pd nanoparticles) in the high temperature calcination process and the leaching of Pd NPs for the catalytic reaction in a liquid phase.The catalyst was characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N 2 adsorption/desorption, elemental analysis and inductively coupled plasma atomic emission spectrometry (ICP-AES). The synthesized catalyst exhibited high catalytic activity in the reduction of p-nitrophenol with NaBH 4 aqueous solution at room temperature. Furthermore, Pd@hTiO 2 had an excellent recyclability, evidenced by being extensively reused for eight times without any substantial loss of activity.

Morphologic control of Sb-rich Sb2Se3 to adjust its catalytic hydrogenation properties for p-nitrophenol

“…16,17 Although the reduction of high concentrations of p-nitrophenol by zero-valent iron systems has been realised at a high operating temperature (85 C), 18 it would proceed easily using NaBH 4 as the reductant at ambient temperature as a model reaction. 1,19,20 Therefore, expensive NaBH 4 was selected as the reductant. Recently, the development of new nanocatalysts for the catalytic reduction of p-nitrophenol has attracted considerable attention.…”

“…Among these catalysts, mesoporous Au/TiO 2 nanocomposites, 17 Au/graphene hydrogel, 21 carbon-protected Au/TiO 2 , 22 Pd@TiO 2 (ref. 19) and Fe 3 O 4 @PS@PAMA-Ag 23 exhibited excellent catalytic performance towards the reduction of p-nitrophenol to p-aminophenol. However, the problem is the high cost of these materials due to the use of noble metals.…”

High catalytic efficiency of Pd nanoparticles immobilized on TiO2 nanorods‐coated ceramic membranes

“…The elements Al and O come from the ceramic membrane, and the elements Si, Pd, and N should be from the grafted silane coupling agent of AAPTS and the loaded Pd nanoparticles . Compared to the spectrum of Pd‐CM, a new peak of Ti 2p can be observed for Pd‐TiO 2 ‐CM, indicating that TiO 2 NRs are successfully grown on the ceramic membrane . Table highlights that the N and Pd for Pd‐TiO 2 ‐CM have significantly larger atomic concentrations than those for Pd‐CM, further confirming that the TiO 2 NRs nano‐coating can promote the loading of Pd nanoparticles.…”

Design, synthesis and applications of core–shell, hollow core, and nanorattle multifunctional nanostructures

“…219 Compared to dense spheres of the same size, the hollow structure is more effective as a catalyst because it allows the outer and inner surfaces to interact with the reactants. Zhou et al 220 have synthesized Pd@TiO 2 hollow core-shell nanospheres as an efficient and reusable catalyst for the reduction of p-nitrophenol with NaBH 4 aqueous solution at room temperature. In addition, this material showed a high recyclability through extensive reuse (eight times) without a pronounced loss of activity.…”