Green Synthesis And Electrocatalytic Performances Of Mental Phosphide

Due to the increase in population and people’s living standards,energy demand has increased dramatically,leading to the exhausting of fossil fuels and damaging our environment.It is therefore becoming increasingly urgent to discover new renewable energy sources.As a clean and pollution-free renewable energy source with high energy density,hydrogen has become the most promising energy fuel for future energy needs.Hydrogen production by electrochemical hydrolysis has become one of the most effective methods due to the clean method and high purity of the hydrogen produced.The overpotential required for electrochemical water splitting is high.Therefore,there is a requirement to create a catalyst to reduce the overpotential required in the water splitting process.Transition metal phosphides（TMPs）have captured much of the focus for their high conductivity,low cost and good stability.Therefore,the design of reasonable,efficient and environment-friendly TMPs electrocatalysts through different modification methods has become the focus of electrochemical water splitting.In this paper,metal phosphide nanomaterials were constructed by a series of simple and rapid methods using a non-toxic and non-polluting phosphorus source,and their intrinsic catalytic activities were investigated by physical and chemical methods and applied to electrochemical water splitting and zinc-air batteries,providing methods and pathways for the development of high efficiency and environmentally friendly metal phosphide electrocatalytic materials.（1）The ultra-small Pt nanoparticles modified with defective Co P（Pt/d-Co P/NPC）with multifunctional electrocatalytic properties were prepared by a simple pyrolysis and chemical reduction process.The synthesized Pt/d-Co P/NPC has a high half-wave potential in 0.1 M KOH and has good stability.Density functional theory（DFT）calculations display that Pt/d-Co P/NPC has stronger adsorption energy and higher catalytic activity for oxygen reduction reaction（ORR）compared with Pt.In addition,the resulting electrocatalysts have excellent catalytic activity for the hydrogen evolution reaction（HER）at overpotentials of 33 m V（1 M KOH）,6 m V（0.5 M H₂SO₄）,and 70 m V（1 M PBS）at 10 m A cm^-2;and superior catalytic activity for the oxygen evolution reaction（OER）in 1 M KOH with an overpotential of 320 m V at 10m A cm^-2.The synthesized Pt/d-Co P/NPC catalysts were assembled as the cathode and anode,respectively,for the water spilitting device and the rechargeable zinc-air battery with excellent activity and long-term stability.Notably,sustainable energy sources can efficiently drive the electrolyzer composed of Pt/d-Co P/NPC to generate bubbles,for example,wind energy,solar energy,demonstrating the potential application of the synthesized catalysts in renewable energy storage.（2）The Ru-Re₃P₄/NPC electrocatalysts with porous nanostructures were prepared by a simple and rapid one-pot method using non-toxic melamine phosphate（MP）as the phosphorus source.The in situ generated nitrogen and phosphorus doped carbon layers avoid the aggregation of nanoparticles,increase the specific surface area,and take a major role in regulating the electrocatalytic activity.In addition,Ru doping also improved the electrocatalytic performance of the nanomaterials.The synthesized Ru-Re₃P₄/NPC exhibited significant electrocatalytic performance towards HER with overpotentials of 39 m V,115 m V and 88 m V at 10 m A cm^-2in basic,neutral and acidic environments,respectively.（3）The Mo P-Ru₂P/NPC nanoparticles with porous nanostructures were prepared by a one-pot method.The synthesized Mo P-Ru₂P/NPC has low overpotentials of 47m V,126 m V and 82 m V(at 10 m A cm^-2)in alkaline,neutral and acidic electrolytes.The prepared catalysts showed remarkable stability.In addition,the water splitting device assembled with Mo P-Ru₂P/NPC and commercial Ni Fe foam as cathode and anode,respectively,required only 1.49 V to drive 10 m A cm^-2.In addition,intermittent sustainable energy sources,including wind,solar and thermal energy,can directly drive the hydrogen production from the water splitting device and then store them accordingly.