Construction And Electrocatalytic Properties Of Non-carbon Support Noble Metal Nanomaterials

With the intensification of climate pollution and the growing energy crisis,the search for green and sustainable energy is a significant scientific challenge.One of the most effective strategies is to develop intelligent green energy storage and conversion systems,such as overall water splitting,fuel cells,and metal-air batteries,but the function of these systems is concerned with the performance of materials.Therefore,rational design of high-performance electrocatalysts is critical.We focus on the construction of non-carbon support noble metal nanomaterials and studying their electrocatalytic performance.In addition,experimental and density functional theory calculations are used to study the electrocatalytic performance and the catalytic reaction mechanism.This work provides a new idea for the design of electrocatalysts with outstanding performance.The main contents of the thesis are summarized as follows:(1)T-Pt-Co₄N catalyst with ginkgo biloba-like morphology were synthesized via solvothermal,tannic acid treated and nitridation procedures,which exhibited remarkable performance in alkaline and neutral electrolytes.Its unique ginkgo leaf-like nanostructure facilitates proton transfer and exposes abundant active sites.The superhydrophilic and aerophobic properties of the surface are beneficial to accelerate the reaction kinetics of HER.Therefore,the prepared T-Pt-Co₄N only requires a low overpotentials of 31 m V and 29 m V to achieve 10 m A cm^-2 in alkaline and neutral electrolytes,surpass the benchmark Pt/C and previously reported values.(2)An innovative one-step corrosion strategy was used to synthesize trace precious metal Pt loaded Ni Fe-LDH electrocatalyst(NF-Na-Fe-Pt)on nickel foam at room temperature.The interaction of LDH and trace precious metal optimizes the balance adsorption of hydroxyl ions and hydrogen atoms,prompting the nanomaterials electrocatalytic performance.More importantly,the NF-Na-Fe-Pt electrocatalyst also exhibits remarkable overall water splitting performance.In this work,the combination of noble metals and transition metal hydroxides opens a new direction for the synthesis of highly efficient electrocatalysts.(3)An innovative one-step etching strategy to rapidly synthesize amorphous Ru O₂-modified Fe OOH nanosheets(FF-Na-Ru)on iron foam(FF)substrates within 1 h.The FF-Na-Ru catalyst exhibits superhydrophilic and aerophobic properties of the surface.In addition,the electronic interaction between Ru O₂ and Fe OOH can significantly improve the electrochemical interface performance to facilitate the electrocatalytic process.Therefore,the FF-Na-Ru electrocatalyst exhibits excellent catalytic activity for HER(30m V at 10 m A cm^-2)and overall water splitting(230 m V at 10 m A cm^-2)in 1 M KOH.On the basis of the electrochemical results,density functional theory(DFT)calculations were performed to investigate the catalytic reaction mechanism.Due to the mentioned advantages,the obtained electrocatalysts exhibit remarkable HER performance and overall water splitting performance,and can be driven by sustainable energy sources,such as sunlight,wind,and thermal energy.In practical applications,the design strategy providing a new perspective for the synthesis of efficient electrocatalysts.