Facile two-step synthesis of nickel nanoparticles supported on 3D porous carbon frameworks as an effective electrocatalyst for urea and methanol oxidation

Abstract

The design and development of facile and environmentally-friendly methods to prepare low-cost, high-activity electrocatalysts are desirable for the development of fuel cells. In our study, a high-efficiency anodic electrocatalyst for the oxidation of urea and methanol based on nickel nanoparticles supported on three-dimensional porous carbon frameworks (Ni/3DPCFs) was designed by an innovative and simple method. This innovative method is based on the preparation of carbon quantum dots (CQDs) and nickel ions (Ni2+) adsorbed on its surface by microwave-assisted synthesis, followed by pyrolysis. The method is notable for simultaneously preparing Ni2+ and CQDs and not requiring a stabilizer, surfactant, or organic solvent. The results of scanning and transmission electron microscopy (SEM and TEM) revealed that the CQDs were converted to 3DPCFs by pyrolysis and nickel nanoparticles (NiNPs) were formed on the surface. The prepared electrocatalyst showed high efficiency for the oxidation of urea and methanol in alkaline media. The electrocatalytic activity of Ni/3DPCFs showed the maximum anodic current density of 102.5 and 153.8 mA/cm2 for urea and methanol oxidation, respectively. This method can provide a simple and novel approach to producing various metallic nanoparticles supported on 3DPCFs as electrocatalysts by two-step microwave-assisted synthesis and pyrolysis without using toxic reagents and surfactants.