Exploring Enhanced Electrocatalytic Hydrogen Evolution by Metal‐Free Highly Conjugated Azomethine‐Functionalized Graphitic Carbon Nitride

Abstract

The water‐splitting reaction via electrocatalyst is a potential method for hydrogen evolution reaction (HER), and metal‐free electrocatalytic material with excellent performance are in great demand for future applications. In this context, a novel, facile, and efficient route for the synthesis of highly conjugated azomethine‐functionalized graphitic carbon nitride (GCN) is proposed. The GCN functionalized with azomethine moiety by using various proportions of GCN–x% dimethyl amino cinnamaldehyde (DMAC) (x = 0.1%, 0.5%, 1.0%, 5.0%, and 10.0%) of p‐DMAC leads to introduction of azomethine moiety onto the GCN matrix that does not affect the original framework of GCN network, but it efficiently enlarges its π‐delocalized system, increases its surface area, and enhances the electrocatalytic properties. All the structural and morphological properties of synthesized materials are analyzed by X‐ray diffraction, Fourier transform infrared, X‐ray photoelectron spectroscopy, Brunauer–Emmett–Teller, High resolution transmission electron microscopy, and field emission scanning electron microscopy, with Energy dispersive spectroscopy analysis. Furthermore, the GCN–5.0% DMAC exhibits superb HER performance with onset potential near to 0 V, and a low overpotential of 18.7 mV at 5 mA cm−2, and extremely ultrasmall Tafel slope (46.8 mV dec−1) in an 0.5 m H2SO4. In this study, the door is laid for interfacial engineering to be used as an efficient method for economically developing electrocatalysts.