Nanoporous gold film: fabrication and role as a catalytic reactor

Abstract

Nanoporous gold (NPG) is attractive due to its high catalytic activity. From an applied and economical point of view, fabricating thin NPG films is recognized to be an ideal approach. Herein, we report an interesting finding that a thin NPG film with a thickness of 90 nm can be prepared on various substrates conveniently by using seed-mediated growth. The film has a nanoporous character with 30-60 nm and 10-30 nm of ligament and pore size, respectively. The high cost-efficiency, adjustable substrates, easy and convenient operation make this film reactor a good candidate for catalyzing both oxidative and hydrogenation reactions.

Essential Role of Electrode Materials in Electrochemiluminescence Applications

“…[16] Gold materials were appliedf or the ECL of luminol in neutral or basic aqueous solution, [32] also in the form of gold nanorods/nanoparticles modifiede lectrodes. [33] In addition to flat electrode surfaces, porous gold electrodes [34] were used to enhance the ECL signal compared to flat gold electrode of CdTe quantun dots [35] or as scaffold for loading Ru(bpy) 3 2 + in as olid state ECL device. [36] As ah istorical note, gold electrodes were used in the first commercial flow cell produced by Igen [37] for its ECL analyser Origen.…”

Plasma–Ice Interface as Thermodynamically Size-Tunable Reaction Field: Development of Plasma-Assisted Freeze Templating

“…The exhibited catalytic ability of the AuNP film synthesized by PFT was comparable to that of nanoporous gold thin film reported previously. 25 Therefore, the AuNP film synthesized by PFT demonstrated catalytic ability comparable to nanoporous gold synthesized by conventional chemical methods.…”

“…The observed hierarchical structure of the AuNP film has been widely reported in a seed-mediated self-assembly synthesis of nanostructured gold thin films. 25,30,40 The formation mechanism of the self-assembled hierarchical structure is typically explained by diffusion limited aggregation (DLA) 30,41,42 in which particles adhere once they collide to each other. In our case, the mechanism of the AuNP film synthesis can also be explained based on the DLA process as follows: AuNPs formed from the auric ions in solution by cryoplasma irradiation were agglomerated to form the hierarchically assembled structures accompanied by the DLA model, and the agglomerated AuNPs were interconnected to each other owing to the further reduction of auric ions by the cryoplasma.…”

“…24 To investigate the catalytic ability of the AuNP film synthesized by PFT, we conducted the reduction of p-nitrophenol as a representative example. 25 In this case, 45 mg of NaBH 4 was added as a reduction agent to 3 mL of 0.085 mM p-nitrophenol solution under stirring. When three pieces of 10 mm long AuNP film line, which was synthesized from a 25 mM frozen solution of auric ions at −10 °C, were added to the solution, the yellow color of the pnitrophenol solution disappeared within 10 min.…”

Nanomaterial-Based Electrochemical and Colorimetric Sensors for On-Site Detection of Small-Molecule Targets

“…Porous thin gold films have shown promise for applications in catalysis, 36 biosensors, 37 fuel cells 37 and supercapacitors 37 as a result of high surface-to-volume ratio, great inplane conductivity, and upgraded electron exchange rates. 37 Such films can be manufactured by either layout-coordinated or template-free strategies.…”