Efficient Electrosynthesis of Azo Derivatives Using Binder-Free Electrodeposited Organic/Ni-Co Nanohybrid Electrocatalyst

Abstract

In synthetic chemistry and pharmaceuticals, azo aromatics are important building blocks with a wide range of applications. However, their environmentally-friendly synthesis has not been extensively studied. Herein, we have synthesized the peptide bolaamphiphile-based organic–inorganic nanohybrid architecture, on a nickel foam (NF) substrate. The electrodeposition method is used to synthesize a Bola/Ni-Co nanohybrid (Bola = FW-AdiA-WF/Ni-Co, AdiA = adipic acid, W = L-tryptophan, F = L-phenylalanine, Ni = nickel nitrate and Co = cobalt nitrate (2:2)) on nickel foam without the need for any additional conductive material or binder. The resulting electrocatalyst is highly effective in selectively facilitating the anodic azo coupling reaction (ACR) of aromatic amines, converting them into azo aromatics at ambient conditions. This reaction takes place in a 1 M KOH electrolyte at a current density of 15 mA in an undivided cell. The electrocatalyst is effective for a broad range of substrates and can tolerate various functional groups. During the electrosynthesis of azo aromatics, the substrate adheres to the surface of electrocatalyst, which prevents the competing oxygen evolution reaction (OER). The use of water as a solvent avoids the need for excessive chemicals, making this electrosynthesis method safe, cost-effective, and environmentally friendly. Furthermore, the electrocatalyst is highly stable and can be reused for up to seven consecutive cycles. This method offers an energy-efficient route for the synthesis of value-added products with high yields for future prospectives.