Spatial Scanning Spectroelectrochemistry. Study of the Electrodeposition of Pd Nanoparticles at the Liquid/Liquid Interface

Abstract

Spatial scanning spectroelectrochemistry is a new analytical technique that provides spectral information at different distances from an electrified liquid/liquid interface where an electrochemical process takes place. As a proof of concept, we have studied two different electrochemical processes at the electrified liquid/liquid interface: (1) Ru(bpy)(3)(2+) transfer through the water/1,2-dichloroethane interface and (2) electrodeposition of Pd nanoparticles at the water/1,2-dichloroethane interface. The instrumental setup developed consists of a movable slit for the light beam to sample at well-defined positions on both sides of the interface, providing important information about the chemical process occurring. If the slit is scanned at different distances from the interface during an electrochemical experiment, a complete picture of the reactions and equilibria in the diffusion layer can be obtained. For example, in the case of the Ru(bpy)(3)(2+), the experiments show clearly how the complex is transferred from one phase to the other. In the case of electrosynthesis of Pd nanoparticles, it is demonstrated that nanoparticles are not only deposited at the interface but diffuse to the aqueous bulk solution. These in situ observations were confirmed by ex situ experiments using transmission electron microscopy.

UV/Vis Spectroelectrochemistry as a Tool for Monitoring the Fabrication of Sensors Based on Silver Nanoparticle Modified Electrodes

“…UV/Vis spectroelectrochemistry has been demonstrated to provide suitable information on the NPs generated on the electrode surface, that is comparable to that obtained by scanning electron microscopy [9]. Spectroelectrochemistry is a multiresponse technique that has been used to study complex reaction mechanisms [10–12]. It yields in-situ spectral information during the electrodeposition of the NPs on the electrode, which allows us to know the type of NPs deposited on the electrode, providing a fast and low-cost analytical method to assure that the electrode has been successfully modified with NPs.…”

Spectroelectrochemical Sensing: Current Trends and Challenges

“…SEC joins the best of electrochemistry and spectroscopy together during an electron‐transfer process. As can be inferred, this multiresponse and “teamwork” technique has been used in a large number of fields, including, for example, electron transfer processes , chemical reaction mechanisms , side reactions , electrocatalysis , corrosion , conducting polymers , solar cells , memory devices , supercapacitors , synthesis and characterization of nanoparticles , carbon nanomaterials , characterization of metal complexes , liquid/liquid interfaces , electrochromic materials or study of compounds of biological interest , among others.…”

Investigation of modified nanopore arrays using FIB/SEM tomography

“…22 The interface between water and 1,2-dichloroethane (DCE), which is also used in the present study, was used for measurements at nanopipettes 3 and nano-sized porous membranes. 23 Additionally, the deposition of Pd-nanoparticles at the water/DCE interface was observed in situ using spatial scanning spectroelectrochemistry introduced by Izquierdo et al 24 Electrochemical processes at the interface were monitored while transferred analytes were recorded simultaneously using UVvisible spectroscopy with a micro-focused beam displayed parallel to the liquid/ liquid interface. The same approach was also used for the study of Au deposition in an ITIES formed from the contact of aqueous and organic phase droplets.…”