Microelectrode-based transient amperometry of O₂adsorption and desorption on a SrTiO₃photocatalyst excited under water

Abstract

Transient amperometry with a microelectrode was applied to a SrTiO3 photocatalyst for water splitting. Operando O2 detection at intervals of 0.1 s indicated light-triggered O2 adsorption and desorption in addition to photocatalytic O2 evolution.

Photo-scanning Electrochemical Microscopy Observation of Overall Water Splitting at a Single Aluminum-Doped Strontium Titanium Oxide Microcrystal

“…The i T transients in Figure A are very fast with the rise time in the range of milliseconds. By contrast, the current transients at a micrometer-sized electrode positioned above a SrTiO 3 photocatalyst film doped with Al were markedly slower, with the rise time in the range of tens of seconds . Our data suggests that the slow response observed in ref is likely due to mass-transport and illumination issues and not a result of the intrinsic OER mechanism of the individual photocatalyst particles.…”

“…35 They measured bimolecular rates of the reaction between the titrant and adsorbate and reported dramatic differences in these rate constants, suggesting that modifications made to the surface influence the reactivity of photogenerated reactive oxygen species. Abrunã and co-workers 36 used SECM in combination with operando-X-ray reflectivity to investigate the changes in structure and reactivity of a SrTiO 3 layer upon application of an external bias. In addition to probing the photogenerated O 2 , they performed SECM to evaluate surface coverage with a reactive OH ad-layer.…”

KTaO3 Wafers Doped with Sr or La Cations for Modeling Water-Splitting Photocatalysts: 3D Atom Imaging around Doping Cations

“…The amount of reaction products is sensitive, often proportional, to the interface area. The authors are currently developing a microelectrode-based method feasible for reaction-rate evaluation on cm-sized photocatalyst films and wafers. , Photocatalytic reaction rate is to be evaluated over doped wafers in future studies.…”

Recent Advances in the Glass Pipet: from Fundament to Applications

“…SECM Probe for Electrochemical Analysis of Inorganic Samples. In the recent two years, the SECM probe was also widely applied for numerous catalytic reactions, including oxygen reduction reaction (ORR), 112 oxygen evolution reaction (OER), 32 hydrogen evolution reaction (HER), 33 hydrogen oxidation reaction (HOR), 113 nitrate reduction reaction (NitRR), 114 and CO 2 reduction reaction (CO 2 RR). 115 Kosaka et al 116 applied operando detection integrated with a SECM microelectrode to determine the absolute OER rate on a highly efficient SrTiO 3 photocatalyst film immersed in a nitrogen-purged KCl solution.…”

“…Also, a nanopipette as a probe of SICM allows to noncontact visualize the topography of complex biological samples such as neuros and 3D cells, , to quantitatively analyze the ionic environment of bacteria and living cells, , and to explore mechanical properties , of cells related to cancer diagnosis with high spatial resolution. Moreover, a nanopipette also exhibits remarkable applications in SECM and SECCM for analysis of numerous catalytic reactions, for example, hydrogen/oxygen evolution reaction, , of inorganic and biological samples. Furthermore, utilizing the functionalized nanopipette with a nanoelectrode sensor is capable of insight into the redox process in the cell level …”