Architecture Design and Catalytic Activity: Multidimensional Cu@Ag Core–Shell Structures for Hydrogenation of 4-Nitrophenol

Abstract

Cu@Ag core–shell structures efficiently integrate the superior properties of Cu and Ag nanoparticles, while simultaneously addressing the critical limitations of poor chemical stability of Cu and high raw material cost of Ag. In this study, multidimensional Cu@Ag core–shell micronanomaterials were successfully synthesized via electroless plating method. The investigation of the relationship between the structure of Cu@Ag core–shell micronanomaterials and their performance in hydrogenation reaction demonstrates that these materials exhibit significant catalytic efficiency and excellent reusability in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Notably, the Cu@Ag core–shell nanosheets (Cu@AgNSs) exhibited the highest recorded mass-normalized rate constant (5.64 × 104 min–1·g–1), which was 4.3 times and 15.7 times higher than that of Cu nanosheets (CuNSs) and Ag nanoparticles (AgNPs), respectively. Combined structural analysis and density functional theory (DFT) calculations confirmed that the catalytic performance is governed by the synergy between the intrinsic electronic effects of the Cu/Ag interface (enhancing hydrogen adsorption and electron transfer) and the synergistic effect resulting from the exposure of interface sites. The findings of this study are valuable for advancing the development of advanced low-dimensional Cu-based micronanomaterials.