Etch it better: A deep eutectic solvent-induced in situ etching phosphorization strategy was proposed to prepare a nickel phosphide-P,O-codoped carbon nanosheet composite (t-Ni−P@POC), which exhibits a low onset potential of 1.20 V vs. RHE and a high current density of 200 mA cm−2 at 1.33 V vs. RHE for electrooxidation of 5-hydroxymethylfurural after electrochemical activation.
The development of catalysts with relatively high current densities at low potentials for the electrooxidation of 5-hydroxymethylfurfural (HMF) is still challenging. In this study, an in situ deep eutectic solvent (DES) etching phosphorization strategy is developed to prepare nickel phosphides encapsulated in P,O-codoped carbon nanosheets (Ni−P@POC). The DES serves not only as an etchant to extract Ni2+ from the nickel foam, but also as a phosphorus source to form nickel phosphides in situ uniformly embedded in the carbon films to produce a sheet structure. The electrooxidation performance is further greatly improved by implementing an electrochemical activation step to transform Ni−P@POC into NiOOH/Ni−P@POC (t-Ni−P@POC). t-Ni−P@POC exhibits a low onset potential of 1.20 V vs. RHE and a high current density of 200 mA cm−2 at 1.33 V vs. RHE for HMF electrooxidation, outperforming most reported catalysts. The as-developed DES etching phosphorization strategy offers a facile, flexible, and universal route for the design of high-performance catalysts with specific nanostructures.Zum Volltext