Construction And Properties Of Mxene-Based Non-Noble Metal Electrochemical Catalysts

Electrolysis of water is one of the technical means to prepare hydrogen energy,and catalysts play a key role in the process of hydrogen production from electrolysis of water,but there are disadvantages such as high cost and poor stability of catalysts,so the development of inexpensive and efficient catalysts is of practical significance for hydrogen production from electrolysis of water.The new two-dimensional material MXene,with good electrical conductivity,hydrophilicity and cation insertability,as well as high specific surface area,can be used to prepare high catalytic activity hydrogen/oxygen precipitation catalysts.Three-dimensional porous catalysts based on MXene can fully expose the catalytic active site and also enhance the transport ability of the material.In this paper,MXene/NF is used as a carrier to construct a variety of non-precious metal electrocatalysts,and the electrocatalytic performance is systematically investigated.The main contents of the paper are as follows:1)MXene（Ti₃C₂T_x）was used as the object of study to prepare MXene intermediate product（MXene/NF）by natural precipitation method,and based on this,Ni-Co-P and MXene/NF were covalently combined by chemical plating technique to construct Ni-Co-P/MXene/NF catalyst.The catalyst took advantage of Ni-Co-P,MXene and NF in electrolytic water catalysis and showed excellent oxygen precipitation performance in 1 M KOH electrolyte.The overpotential was as low as 211 m V and the Tafel slope was only 47m V·dec^-1 at a current density of 100 m A·cm^-2.2)The Ni-W-B/MXene/NF composite catalyst was obtained by preparing a coating of MXene intermediates on the surface of NF using nickel foam（NF）as the backbone and depositing three-dimensional sheets of Ni WB on the coating using a chemical plating method.The catalyst showed excellent hydrogen precipitation performance throughout the p H interval.The overpotentials were 22 m V,64 m V,and 15 m V with Tafel slopes of 49m V·dec^-1,88 m V·dec^-1,and 107 m V·dec^-1 at the current density j=10 m A·cm^-2 in acidic,neutral,and alkaline electrolytes,respectively.3)A NiCoFe-LDH/MXene/NF catalyst with a three-dimensional floral structure was prepared on the MXene/NF surface by using NF as the substrate material and covering the NF surface with MXene by electrostatic adsorption,followed by the hydrothermal method.When the current density was 100 m A·cm^-2,the overpotential and Tafel slope were 173 m V and 24 m V·dec^-1,respectively.