title: Scanning electrochemical cell microscopy platform for ultrasensitive photoelectrochemical imaging.
abstract: The development of techniques for nanoscale structure-activity correlations is of major importance for the fundamental understanding and rational design of (photo)electrocatalysts. However, the low conversion efficiency of characteristic materials generates tiny photoelectrochemical currents at the submicrometer to nanoscale, in the fA range, which are challenging to detect and measure accurately. Here, we report the coupling of scanning electrochemical cell microscopy (SECCM) with photoillumination, to create a submicrometer spatial resolution cell that opens up high resolution structure-(photo)activity measurements. We demonstrate the capabilities of the technique as a tool for: (i) high spatial resolution (photo)activity mapping using an ionic liquid electrolyte at a thin film of TiO2 aggregates, commonly used as a photoanode in dye sensitized solar cells (DSSCs) and (ii) in situ (photo)activity measurements of an electropolymerized conjugated polymer on a transparent Au substrate in a controlled atmospheric environment. Quantitative data, including localized (photo)electrochemical transients and external quantum efficiency (EQE), are extracted, and prospects for further technique development and enhancement are outlined.
authors: Department of Chemistry, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL United Kingdom.
authors: Barak D B
authors: BD
authors: Aaronson
authors: Department of Chemistry, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL United Kingdom.
authors: Joshua C
authors: JC
authors: Byers
authors: Department of Chemistry, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL United Kingdom.
authors: Alex W
authors: AW
authors: Colburn
authors: Department of Chemistry, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL United Kingdom.
authors: Kim
authors: K
authors: McKelvey
authors: Department of Chemistry, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL United Kingdom.
authors: Patrick R
authors: PR
authors: Unwin
mesh_terms: D055664:Electrochemical Techniques; D004573:Electrolytes / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D064347:Microscopy, Electrochemical, Scanning; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry
chemical_list: D004573:Electrolytes; D052578:Ionic Liquids; D011108:Polymers; C009495:titanium dioxide; D006046:Gold; D014025:Titanium