Work

Laser-induced photochemical reduction for the production of gold and silver nanoparticles on gold nanostructures

Year: 2025

Type: article

Abstract: • The study focuses on photoreduction of chloroauric acid and silver nitrate solution on gold nanostructures. • We employed 445 nm CW and two-photon femtosecond laser for irradiation purposes. • A 445 nm CW laser was used to deposit gold nanoparticles on gold nanostructures and additionally silver nanoparticles on gold nano triangular plates. • An 800 nm femtosecond laser was employed to deposit silver nanoparticles on gold nanorods and gold nanoplates. • 3D silver nanodendritic structures were grown on gold thin film using 800 nm femtosecond laser. This research explores two methods for the photo-chemical reduction of gold and silver ions, utilizing either a continuous-wave (CW) laser or a femtosecond laser, in conjunction with plasmon-assisted hot electrons. The study focuses on the photoreduction of chloroauric acid (HAuCl 4 ) and silver nitrate (AgNO 3 ) solutions containing gold nanostructures under irradiation from either CW or femtosecond laser. Specifically, we employed a 445 nm CW laser to irradiate gold nanowires, formed through the photo-driven self-assembly of gold nanorods, in HAuCl 4 solution. Through this photoreduction process, we observed the newly formed gold nanoparticles on the surface of gold nanowires. In addition, we also used 445 nm to irradiate gold triangular nanoplates in AgNO 3 solution with ascorbic acid as a reducing agent. We observed that silver nanoparticles clearly formed and attached to the edges of a gold triangular nanoplate. In another approach, an 800 nm femtosecond laser was used to irradiate gold nanorods, gold triangular/hexagonal nanoplates and a gold nanofilm in AgNO 3 solution with a reducing agent under inverted microscopy. For instance, silver nanoparticles were observed to attach to the edges of the gold triangular and hexagonal nanoplates, facilitating the growth of the nanoplates. The formation of photochemically reduced nanoparticles was confirmed using energy-dispersive X-ray spectroscopy. Notably, 3D silver dendritic structures were synthesized with the femtosecond laser and deposited onto the gold nanofilm, a process attributed to two-photon absorption effect. The high sensitivity of these immobilized dendrites for surface-enhanced Raman scattering applications was also demonstrated.

Source: Results in Physics

DOI: 10.1016/j.rinp.2025.108152

Authors: Naushad Ahmad Khan, Yi-Han Kuo, Shang-Yang Yu, Yun-Cheng Ku, Kuo-Yung Hung, Jiunn-Woei Liaw

Institutions: Chang Gung University, National Taiwan University, Ming Chi University of Technology, Linkou Chang Gung Memorial Hospital

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,920

Funders: National Science and Technology Council, Chang Gung Memorial Hospital, Chang Gung University, Chang Gung Memorial Hospital, Linkou