Study On Synthesis Of Carbon Nanotubes Modified And Mn Doped Nickel Phosphide And Their Electrochemical Hydrogen Evolution Properties

With the increasing demand for new energy in the future,clean hydrogen energy with high combustion valued has become the focus of attention.The existing hydrogen production methods mainly suffer from environmental pollution and low product purity,which requires the use of environmentally friendly and efficient hydrogen production technology by electrolysis of water.However,the high cost and scarcity of catalysts are the key problems in the electrolysis of water for hydrogen production.Therefore,it is of great significance to develop and prepare an abundant and low-cost non-noble metal catalyst to replace noble metal catalyst for the hydrogen evolution reaction（HER）.Transition metal phosphides（TMPs）have great potential in catalytic applications to alleviate the energy crisis.The studies have shown that catalysts based on porous materials have the advantages of the large specific surface area and good activity.The synergistic effect formed by the elemental composition of the material is also conducive to enhancing electron transport and accelerating the efficiency of hydrogen evolution.Therefore,this study mainly prepared Ni-P/CNTs and Mn-NiP electrocatalyst materials.The main research contents are as follows.（1）The porous skeleton nickel powder was prepared from Ni-Al alloy by gas atomization and alkaline solution leaching method.The temperature and time of leaching reaction as well as the difference in the pore structure of the powders prepared under different particle sizes were discussed.It is concluded that the skeleton nickel powder prepared by this method has certain catalytic activity and can be used as an effective precursor material of the catalyst.（2）The Nickel phosphide arrays（Ni-P/CNTs）catalysts were prepared on the surface of porous nickel powders supported by carbon nanotubes by a simple and effective high-temperature phosphating method.Under acidic conditions,the Ni-P/CNTs catalyst prepared at 700℃for 60 min showed better catalytic activity than the catalysts prepared under other process conditions in this experiment.This may be related to the array morphology,electrochemically active surface area and P content of the catalyst.Also,the catalyst prepared under this condition also showed excellent stability of hydrogen evolution.This work will provide a promising pathway for designing various transition metal compounds and exploring the performance in catalysts for energy-related catalysis processes using porous metal materials.（3）Using the above method,the second metal manganese powder was doped into porous nickel powder and red phosphorus powder.After high-temperature phosphating,a kind of multiphase nickel phosphide(Ni₃P,Ni₂P,Ni₁₂P₅)catalyst material（Mn-NiP）with bimetallic composition was constructed.Benefiting from the regulation effect of doped Mn on the electronic structure of Ni and the mutual electronic interaction between Ni and P,the hydrogen evolution activity of the catalyst doped with an appropriate amount of Mn has increased.The hydrogen evolution activity of 3Mn-NiP in the full p H range was mainly explored.The results showed that the overpotentials required for 3Mn-NiP to generate 10 m A?cm^-2 current density in 0.5 M H₂SO₄ and 1.0 M KOH were 164 and 77 m V,respectively.It showed more excellent HER activity in an alkaline environment.At the same time,3Mn-NiP exhibited excellent electrochemical durability in an alkaline environment and showed no significant decrease in activity after the continuous test for 24 hours.