Optimizing the Electrocatalytic Hydrogen Production with Vanadyl Porphyrin Impregnated on Mesoporous SiO2 Nanoparticles

Abstract

Vanadyl octaethyl porphyrin (VOP) impregnated on SiO₂ nanoparticles (SiO₂@VOP) was investigated as an electrocatalyst for the water-splitting reaction for the cathodic hydrogen evolution reaction (HER). Multi-valent oxidation states of VO²⁺ center and multi-electron transfer properties of the porphyrin ring made this complex a potential candidate for the electrocatalytic processes. Altering the electrode modification protocol by changing the amount of the VOP, carbon black (CB), and Nafion (Nf) binder on the modification influenced the active sites, thus consequently enhancing the electrocatalytic activity of SiO₂@VOP composites. Electrocatalytic HER measurements indicated excellent activity with low overpotential (108 mV), small Tafel slope (98 mV/dec), and high current density stability with the GCE/CB@SiO₂@VOP(B) electrode.