Photothermal reduction of 4-nitrophenol using rod-shaped core–shell structured catalysts

Abstract

Metal nanoparticles can be used in the advanced applications in catalysis due to their multi-functionality and easy tunable of catalyst size. Especially, nanoparticles composed of various metallic species exhibit valuable properties such as localized surface plasmon resonance (LSPR), which was the result of absorption of resonant light. Gold nanoparticles (AuNPs) absorb light strongly and readily convert photon energy into heat quickly and efficiently via localized photothermal effect. Therefore, herein, we tried to improve the catalytic performance through the photothermal effects via LSPR of NPs. To demonstrate this effect, a 4-NP reduction test was performed with representative materials Au and Pd were used. In addition, core–shell structure was utilized to easy recover the metal catalysts. To induce magnetic properties in structured catalysts and prevent the oxidization of NPs, iron oxide and silica was used as core and shell materials, respectively. The photothermal conversion of the rod-shaped core–shell structured catalysts decorated with PdNP and AuNP was 8.12% and 57.55%, respectively. The photothermal effect of the catalyst was evaluated by performing catalytic reduction of 4-NP based on the prepared particles, and the primary rate constant for Pd and Au catalysts was enhanced as 18% and 41% through infra-red irradiation, respectively.