Photocatalytic Enhancements to the Reduction of 4-Nitrophenol by Resonantly Excited Triangular Gold–Copper Nanostructures

Abstract

The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride serves as a well-established model reaction for assessing the catalytic activity of metal nanoparticles. While many of the studied nanoparticles are plasmonic in nature, there is little understanding of whether significant photocatalytic enhancements to the reaction rate are achievable. Here, we assess the catalytic and photocatalytic properties of highly faceted, substrate-immobilized nanoprism-like AuCu structures synthesized using a vapor phase templated-assembly technique.The so-formed structures have a bimetallic composition which is well-recognized for its catalytic capabilities as well as a strong localized surface plasmon resonance in the visible spectrum which gives rise to enhanced near-fields at the tips of the triangle. Using a dip catalyst modality, the structures are demonstrated as heterogeneous photocatalysts with a 32-fold enhancement to the reaction rate when resonantly illuminated with 10 mW/cm 2 laser light. The study demonstrates the potential of such structures as photocatalysts and validates the reduction of 4-nitrophenol as a reaction useful in assessing the photocatalytic capabilities of plasmonic nanostructures.

Ag Nanoparticles-Based Zinc Hydroxide-Layered Hybrids as Novel and Efficient Catalysts for Reduction of 4-Nitrophenol to 4-Aminophenol

“…[1][2][3] Therefore, reduction reaction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) is important because nitrophenols and their derivatives are obtained during the production of herbicides, pesticides, synthetic dyes, etc.…”

“…[1][2][3] Among them, the borohydride reduction of 4-NP to 4-AP by metal nanoparticles such as Ag, Au, Pt and Cu is particularly attractive because this reaction can be performed in aqueous solution under mild condition. [1][2][3][4][5][6][7][8][9][10] Metal nanoparticles (NPs) have a variety of interesting properties, which enable them to play significant roles in a broad range of optic-electronic, biochemical and catalytic applications. 1,3,4 In special, silver nanoparticles (AgNPs) have become a central topic of academic and industrial interest as a promising candidate for next-generation nanocatalysts.…”

“…[1][2][3][4][5][6][7][8][9][10] Metal nanoparticles (NPs) have a variety of interesting properties, which enable them to play significant roles in a broad range of optic-electronic, biochemical and catalytic applications. 1,3,4 In special, silver nanoparticles (AgNPs) have become a central topic of academic and industrial interest as a promising candidate for next-generation nanocatalysts. 5 AgNPs were the first one of metal nanocatalysts to be employed for the reduction of 4-NP to 4-AP in presence of NaBH 4 .…”

“…Surface coating with surfactants and/or various chemical modifications of the metal NPs have been carried out to stabilize them and maintain the original size dispersions. 2,3,7 Another effective approach to inhibit aggregation is to immobilize the metal NPs onto the various supports, such as metal oxides, 1,2,8 boron nitride 4 or layered materials. 9 In fact, layered material-NPs hybrids are attracting attention for practical applications due to their mechanical and catalytic properties.…”

Scalable Synthesis of Ag Networks with Optimized Sub-monolayer Au-Pd Nanoparticle Covering for Highly Enhanced SERS Detection and Catalysis

“…Their properties for these applications depend heavily on surface morphology1011 and sizes121314, including for example hierarchically distributed pores’ sizes1516 that provide superior access to active sites. Designed synthesis of nanostructures with novel surface morphologies and tailored sizes has therefore become very important.…”