Porphyrin macrocycle-stabilized gold and silver nanoparticles and their application in catalysis of hydrogen peroxide

•Amine porphyrin used as stabilizer to functionalize nanoparticles first time.•Synthesized nanoparticles are spherical in shape.•Nanoparticles are 3–5 nm in diameter.•Nanoparticles act as electron mediators and good conductors.•Nanoparticles reduce the hydrogen peroxide efficiently at lower overvoltage.

Gold and silver nanoparticles are stabilized using a cobalt aminophenyl porphyrin macrocycle by a one-step technique. The resultant nanoparticles were characterized by electronic absorption spectroscopy for plasmonic absorption peak, transmission electron microscopy and X-ray diffraction. The synthesized gold and silver nanoparticles possess a relatively homogeneous and narrow size distribution. Both gold and silver nanoparticles have an average diameter of around 5 nm with spherical shape. The porphyrin-stabilized nanoparticles show better charge transfer kinetics and act as good electron mediators. The nanoparticles-coated/modified electrodes are found to be good electrocatalysts for the reduction of hydrogen peroxide. The enhancement of catalytic activity is due to the high surface-to-volume ratio and high surface energy of the nanoparticles.

Graphical abstractCVs of electrocatalytic reduction of H2O2 with (i) Bare GC; GC modified with (ii) CoTAPP; (iii) capped silver nanoparticles and (iv) gold nanoparticles. The electrolyte is phosphate buffer, pH 7.0. Scan rate is 50 mV/s.Figure optionsDownload full-size imageDownload as PowerPoint slide