20 / 2023-07-04 16:44:18

Liquid-Phase Topological Conversion to Construct Metal Phosphides and Their Application in Electrocatalytic Water Splitting

Metal Phosphide,Topological Conversion,Electrocatalytic Oxygen Evolution

Phosphorus Material Chemistry and Applied Science > 1) Phosphorus chemistry in material science

Metal phosphides have good conductivity and a large number of surface unsaturated atoms, and show excellent electrocatalytic properties. We develop the low-temperature liquid-phase topological conversion technique to construct metal phosphides. This technique contains a one-step reaction of metal-organic framework (MOF) and white phosphorus (P₄) under solvothermal conditions, which can retain the spatial topological structure of MOF into the phosphides, and can generate high specific surface area phosphides with micro- and nano-porous structure. Metal phosphides (Ni_1-xFe_xP_y and Co_1-xFe_xP_y) constructed by this method have excellent electrocatalytic oxygen evolution performance. In 1 M KOH, (Ni_0.73Fe_0.27)₂P only needs 243 mV overpotential to achieve 10 mA cm^-2 oxygen evolution current densities. Under the condition of long-term electrolysis, the surface gradually transforms into metal hydroxides. The phosphides prepared by this method can expose a high proportion of electrochemical active sites, can ensure the electrolyte penetration and quick oxygen release, and the electronic effect between Ni and Fe significantly improves the performance of electrocatalytic oxygen evolution. Changing the reaction conditions can easily modulate the structure of the product, and this technique lays the foundation for the study of the electrocatalytic oxygen evolution performance, structure-activity relationship, active site structure and interface reconstruction process of metal phosphides.