An effective strategy for fabricating highly dispersed nanoparticles on O-C3N4 with enhanced electrocatalytic activity and stability

Highlights: • O-C₃N₄ with rich oxygenated functional groups can effectively anchor CoFe₂O₄ NPs. • Highly dispersed CoFe₂O₄ NPs with small particle size were fabricated on O-C₃N₄. • CoFe₂O₄/O-C₃N₄ exhibited enhanced OER performance compared with CoFe₂O₄. Uniform distribution of nanoparticles (NPs) with small particle size is hardly controllable, which has an impact on the electrocatalytic properties. In this work, CoFe₂O₄/oxygen-doped graphitic carbon nitrogen (O-C₃N₄) was synthesized by glycine-nitrate combustion method, which has many advantages such as high compositional homogeneity and fine particle size. O-C₃N₄ as a support possessing abundant oxygenated functional groups can provide more active sites for anchoring metal ions, and effectively avoid or minimize the growth and aggregation of CoFe₂O₄ NPs. As a result, CoFe₂O₄ NPs with a number-mean particle size of 5.06 ± 0.42 nm were homogeneously fabricated on the surface of O-C₃N₄. Moreover, the performance of catalysis was estimated using oxygen evolution reaction (OER) as a model system. The OER performance was remarkably improved including long-term stability and the overpotential of CoFe₂O₄/O-C₃N₄ hybrid for 10 mA/cm² current densities with a decrease of 131 mV and 61 mV compared with CoFe₂O₄ and CoFe₂O₄/graphitic carbon nitrogen (g-C₃N₄) hybrid, respectively. These indicate that oxygenated functional groups on O-C₃N₄ not only leads to homogeneous distribution of CoFe₂O₄ NPs, but also improves the performance for OER. Finally, O-C₃N₄ could act as a novel support to enhance the dispersion of NPs for the further application in catalysis.