Study On Electrodeposition Preparation And Properties Of Copper-based Transition Metal Catalytic Materials

The energy source of electrolytic water unit is the intermittent conversion of electrochemical energy into hydrogen and oxygen,which is considered as a promising new energy technology.At present,a lot of materials based on precious metal materials,non-precious metal materials and even non-metal composite complexes have been studied for electrocatalytic hydrogen and oxygen production.However,due to the limited stock of precious metals on earth and their high price,they could not further meet the needs of industrial production,which prevented their large-scale production and development.Therefore,the search for a kind of abundant,cheap,environmentally friendly catalytic material that can replace precious metal catalysts has become a research hotspot in various countries.Two-element FeS_x catalyst and three-element S-NiFe₂O₄/Ni-Fe alloy/CF catalyst were synthesized on copper foam（CF）substrate by electrodeposition:（1）The metallic elements Fe and non-metallic elements S were deposited on the surface of foamed copper（CF）substrate by electrodeposition with low eutectic solvent,namely FeS_x/CF.The introduction of sulfur made the microstructure of the catalyst significantly changed,and it was found that the iron-sulfur nanosheets intercrossed and grew vertically,forming cauliflower nanospheres.FeS_x/CF electrode materials exhibit excellent catalytic water oxidation and reduction properties in alkaline solution.The oxygen evolution and hydrogen evolution overpotential corresponding to 10 m A cm^-2were 340 m V and-178 m V（vs.RHE）respectively,and there was no obvious attenuation after 24 h stability test of hydrogen evolution and oxygen evolution.（2）A porous structure of nickel-iron-sulfur composite was designed and synthesized.The hollow nickel-iron-sulfur nanoparticles were loaded onto the surface of copper foam（CF）,which was used as a dual-function,high-efficiency,full-electrolysis catalyst.Firstly,the hydrogen evolution reaction of S-NiFe₂O₄/Ni-Fe alloy/CF catalyst in 1.0 M KOH was tested.The composite had excellent electrocatalytic activity,and the overpotential was-66 m V at 10 m A cm^-2.Secondly,S-NiFe₂O₄/Ni-Fe alloy/CF catalysts can also be used in basic oxygen evolution reactions.The overpotential of the S-NiFe₂O₄/Ni-Fe alloy/CF catalyst was 220 m V at 10 m A cm^-2,showing good OER performance.（3）The prepared symmetrical device FeS_x/CF electrode can drive the complete water in 1.0 M KOH by an electrolytic cell with rated voltage of 1.67 V.However,in the two-electrode system consisting of S-NiFe₂O₄/Ni-Fe alloy/CF electrode,the current density of 10 m A cm^-2 could be reached by using only 1.62 V battery voltage,and the corresponding voltage remained almost unchanged under the current density of 10 m A cm^-2 for continuous electrolysis for 60 h.In summary,the s-NiFe₂O₄/Ni-Fe alloy/CF catalytic composite material prepared had highly efficient electro-catalytic activity,which provided a new idea for further improving the electrocatalytic water-soluble reaction performance of sulfides.