Single-Fe-Atom Catalyst for Sensitive Electrochemical Detection of Caffeic Acid

A single-atom catalyst (Fe SAs/-N-C) with excellent stability and conductivity was strategically fabricated via high-temperature calcination using the NiFe layered double hydroxide (LDH)/ZIF-8 composite as precursors. With the help of Ni as a catalyst, a great number of carbon nanotubes were produced whereby the isolated carbon bulks were interconnected to form an island-bridge-like 3D network structure, which greatly enhanced the exposure of active sites and the electron transfer. Accordingly, caffeic acid (CA) with versatile biological and pharmacological activities was chosen as the model analyte. The Fe SAs/-N-C with Fe-N-4 as the catalytic active site was employed to establish the electrochemical sensing of CA with satisfactory sensitivity, selectivity, and long-term stability. This work expands the application range of single-atom catalysts and contributes a significant reference for the synthesis of hybrid double-atom catalysts.

Automated summary

A single-atom catalyst (Fe SAs/-N-C) with excellent stability and conductivity was successfully fabricated via high-temperature calcination using the NiFe layered double hydroxide (LDH)/ZIF-8 composite as precursors. The carbon nanotubes produced with the help of Ni catalyst formed an island-bridge-like 3D network structure, greatly enhancing the exposure of active sites and electron transfer. The Fe SAs/-N-C with Fe-N-4 as the catalytic active site was employed for the electrochemical sensing of CA, showing satisfactory sensitivity, selectivity, and long-term stability. This work expands the application range of single-atom catalysts and provides a significant reference for the synthesis of hybrid double-atom catalysts.