Scanning Electrochemical Cell Microscopy Investigation of Single ZIF-Derived Nanocomposite Particles as Electrocatalysts for Oxygen Evolution in Alkaline Media.
Tsvetan TarnevHarshitha Barike AiyappaAlexander BotzThomas ErichsenAndrzej ErnstCorina AndronescuWolfgang SchuhmannPublished in: Angewandte Chemie (International ed. in English) (2019)
"Single entity" measurements are central for an improved understanding of the function of nanoparticle-based electrocatalysts without interference arising from mass transfer limitations and local changes of educt concentration or the pH value. We report a scanning electrochemical cell microscopy (SECCM) investigation of zeolitic imidazolate framework (ZIF-67)-derived Co-N-doped C composite particles with respect to the oxygen evolution reaction (OER). Surmounting the surface wetting issues as well as the potential drift through the use of a non-interfering Os complex as free-diffusing internal redox potential standard, SECCM could be successfully applied in alkaline media. SECCM mapping reveals activity differences relative to the number of particles in the wetted area of the droplet landing zone. The turnover frequency (TOF) is 0.25 to 1.5 s-1 at potentials between 1.7 and 1.8 V vs. RHE, respectively, based on the number of Co atoms in each particle. Consistent values at locations with varying number of particles demonstrates OER performance devoid of macroscopic film effects.
Keyphrases
- high resolution
- single cell
- label free
- high throughput
- gold nanoparticles
- single molecule
- cell therapy
- mass spectrometry
- quantum dots
- electron transfer
- reduced graphene oxide
- ionic liquid
- optical coherence tomography
- molecularly imprinted
- ms ms
- stem cells
- electron microscopy
- human health
- bone mineral density
- risk assessment
- highly efficient
- climate change
- bone marrow
- metal organic framework