Fig. 2: Single-atom models and SAC-FCS analysis.
From: Identifying the active sites in unequal iron-nitrogen single-atom catalysts
a Overlapped EDS mappings of the Fe and Co atomic distribution of the single-site metal phthalocyanine model. The cyan and blue pixels represent the Fe and Co element signals, respectively. b Single-molecule fluorescence signals, and c the experimental autocorrelation data and fitting curves of the FePc/CoPc-0.3 model from the standard SAC-FCS method. The inset in (b) is the magnified fluorescence trajectory showing the high time resolution of the fluorescence correlation spectroscopy. d Histogram of the calculated FePc probability distribution from 500 times of the autocorrelation fitting. e Binary FePc/CoPc-a and f ternary FePc/CoPc/NiPc-a catalytic models with different SAC-FCS experimental and fitting ratios of the FePc active sites. The a âś• 100% represents the actual percentage of FePc in the model, which ranges from 0.1 to 0.9.
