Study On The Preparation Of Nickel/Cobalt/Platinum Based Thin Films By Liquid Phase Method And Their Electrocatalytic Hydrogen Evolution

Hydrogen production by electrolysis of water has the advantages of easy operation,low energy consumption,and high purity of hydrogen production,which has attracted more and more attention.The high cost of electricity has hindered the large-scale promotion of this technology.The catalyst can significantly improve the reaction kinetics of electrolyzed water and reduce the cost of hydrogen production by electrolyzing water.Therefore,the development of a catalyst for hydrogen production from electrolysis of water with high catalytic activity and high stability is of great significance to promoting the industrialization of hydrogen energy.The precious metal platinum(Pt)is considered to be an ideal hydrogen evolution reaction(HER)catalyst.Pt resources are scarce and expensive,making it difficult to realize commercial applications.Accelerate the industrialization of hydrogen energy by reducing the amount of Pt used in HER catalysts;or developing non-precious metal catalysts with low price,high catalytic activity and stability.Nickel(Ni),cobalt(Co)and other low-cost,abundant transition metals have good HER catalytic activity and are ideal substitutes for precious metal catalysts.The electronic structure of transition metals can be further enhanced by doping with non-metallic elements.Catalytic activity.The use of low-cost,abundant non-metallic phosphorus(P)elements and transition metal-generated transition metal phosphides can further improve the catalytic performance and stability.Transition metal phosphides have been paid attention to by more and more scientific researchers.Based on the composition design strategy and morphology design strategy,the author designed the Pt-P composite film and the NiCoLDH/Pt-like sandwich structure HER electrocatalyst with NiCoLDH/Pt supported on the Pt nanolayer,which can effectively improve the catalytic performance of Pt and reduce the usage of Pt.At the same time,a Pt-free transition metal Ni,Co electro-phosphide HER catalyst was prepared.All three HER electrocatalysts exhibited excellent HER activity.The main research contents are as follows:1.The Pt-P composite thin film HER catalyst was prepared by using aluminum coupled metal as the catalyst carrier,and the preparation conditions were optimized.Through SEM,XPS and other characterizations,it is found that Na H2PO2 can adjust the electronic structure of Pt,help refine Pt nanoparticles,expose Pt to a larger specific surface area,thereby improve the HER catalytic performance of Pt and reduce the cost of the catalyst.Electrochemical tests show that the Pt-P composite film has good HER catalytic activity,which is comparable to commercial Pt/C;higher stability,better than pure Pt film and commercial Pt/C catalyst.In addition,aluminum foil was used to partially cover the foamed nickel(NF),and the Pt-P composite film and pure Pt film were prepared by the same method.The Pt-P composite film supported on NF also showed excellent catalytic activity and stability.At the same time,it is also verified that the method of using aluminum coupling metal has universal applicability in preparing metal thin films.2.The NiCoLDH/Pt HER catalyst was prepared by a one-step hydrothermal reaction method,and the preparation conditions were optimized.Electrochemical tests show that when the current density is 10 m A cm-2,the overpotential of NiCoLDH/Pt-450 is 52 m V(i R correction).After 5 000 cycles of cyclic voltammetry(CV)testing,the LSV curves before and after the NiCoLDH/Pt-450 test basically overlapped,showing excellent catalytic stability.NiCoLDH/Pt has been tested for stability for 12 hours at a constant potential of 1.11 V,and the current density is maintained at about73% initially,which further shows that NiCoLDH/Pt-450 has excellent stability.3.Using Pt sheet as the positive electrode and NF as the negative electrode,NiP/NF and CoP/NF HER catalytic films were prepared and the preparation conditions were optimized.The electrochemical test shows that when the current density is 10 m A cm-2,NiP/NF and CoP/NF show lower HER overpotential;after 5 000 CV tests,NiP/NF and CoP/NF composite films show better Good catalytic stability;NiP/NF and CoP/NF films have undergone a 9 000 s stability test under constant potentials of 1.09 V and1.15 V,and the current density has a small decrease,which further shows that NiP/NF and CoP/NF composite films Excellent stability.