Gold Nanoparticles Grown by Galvanic Replacement on Graphene-Coated Aluminum Panels as Large-Area Substrates for Surface-Enhanced Raman Scattering

Abstract

Galvanic replacement (GR) is a widely used method to obtain substrates with nanostructure morphologies. However, there are substantial challenges related to the uniformity of the deposited nanostructures, the preparation of large-area nanocomposites, and the alteration of the morphologies deposited on substrates. Graphene was introduced into the surface of the aluminum panels in this study prior to conducting the GR reaction to incorporate graphene advantages of extremely high electrical conductivity and electron mobility. The experimental results revealed that the morphological consistency and particle densities of gold nanoparticles deposited on panels with graphene were much higher than those deposited on panels without graphene. Moreover, gold nanoparticles were deposited on the surfaces with graphene prior to deposition on those without graphene. Ordered large-area gold/graphene/aluminum hybrid nanocomposites can be obtained with desired morphologies by altering the preparation conditions. Finally, the feasibility of using the as-prepared gold hybrid nanocomposites as surface-enhanced Raman scattering (SERS) substrates was examined. The results indicated that the Raman signal enhancement factors of the as prepared substrates were varied as the preparation condition changed due to the difference in the morphologies. Under the optimal condition, a high enhancement factor of approximately 3 × 108 with good reproducibility was found, which demonstrates the potential of utilizing the as-prepared gold hybrid nanocomposites in SERS and other sensing applications.

Direct Bottom-UpIn SituGrowth: A Paradigm Shift for Studies in Wet-Chemical Synthesis of Gold Nanoparticles

“…Graphene-Based Nanomaterials . As with TMDs, nucleation can also be promoted to occur on pristine graphene, , but defect sites are most effective at promoting metal nanoparticle nucleation. Among the different possible defects that may exist in graphene (single-carbon vacancies, multiple-grouped vacancies, impurities, foreign atoms substitution, etc .…”

Highly Uniform Fabrication of Gold Nanoparticles on Carbon Nanotube Sheets for Sensors Based on Surface-Enhanced Raman Spectroscopy with Improved Reproducibility

“…Such a reshaping effect from DMSO on Au and Ag particles has been reported by other researchers too. 33,34 It has been demonstrated that DMSO binds gold atoms in a preferential way. 35 For instance, it has been reported that both O and S from DMSO could coordinate with the surface of Au nanocrystals, which stabilizes Au {311} facets and creates Au NPs in the trapezohedral shape.…”

Controllable Synthesis of Silicon‐Based Nanohybrids for Reliable Surface‐Enhanced Raman Scattering Sensing

“…GD reaction is an electrochemical process that involves the redox reaction to reduce metal ions to metallic nanoparticles on the interface of substrate at ambient temperature without reducing agent. [42][43][44][45][46][47][48][49][50][51][52][53] Typically, the entire GD reaction includes an oxidation reaction (anodic electrode, Si + 6F − → SiF 6 2− + 4e − ) and a reduction reaction (cathodic electrode, Ag…”

“…GD reaction is an electrochemical process that involves the redox reaction to reduce metal ions to metallic nanoparticles on the interface of substrate at ambient temperature without reducing agent. [ 42‐53 ] Typically, the entire GD reaction includes an oxidation reaction (anodic electrode, Si + 6F − → SiF 6 2− + 4e − ) and a reduction reaction (cathodic electrode, Ag + + e − → Ag 0 or Au + + e − → Au 0 ) (Figure 3a). In particular, metallic ion is reduced on the silicon wafer surface to form metallic nanoparticles when the redox potentials of metallic ion ( e.g ., Ag + /Ag = 0.799 V) are much higher than that of silicon oxide layer ( e.g ., SiF 6 2− /Si = −1.2 V).…”