Study On Photocatalytic Hydrogen Production Performance Of Platinum Modified Covalent Triazine Framework

The development of a low-cost,high-activity and stable photocatalyst to efficiently convert solar energy into hydrogen energy deserves attention and research.Despite decades of efforts,only a few organic catalysts have the characteristics of high efficiency and high reutilization rate under visible light.In recent years,people have paid close attention to the synthesis of semiconductor polymers,a highly ordered catalyst based on covalent triazine framework（CTF）has come into view.Its outstanding performance is attributed to the ordered molecular structure,abundant active sites and long life.The triazine ring and benzene ring in the catalyst have the characteristics of electron-withdrawing and electron-donating,respectively,and can act as the active site of the interface to accelerate the redox reaction.This provides a new generation of heterogeneous photocatalysts for the utilization of solar energy.They have three key characteristics of the photocatalytic process,namely stability,non-toxicity and visible light activity,which makes them very attractive research objects.In this thesis,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,transmission electron microscopy（TEM）and high-resolution TEM（HRTEM）,valence band XPS（VB-XPS）,and ultraviolet-visible diffuse reflection spectrum（UV-Vis DRS）,Brunauer-Emmett-Teller（BET）surface area,electrochemical impedance spectroscopy（EIS）,photoluminescence（PL）spectroscopy and PL lifetime spectroscopy to characterize the catalyst samples to prove the physical and chemical properties of the catalyst and its The relationship between the performance of photocatalytic decomposition of water to produce hydrogen.The experimental results show that platinum doping not only promotes the collection of visible light,but also promotes the separation and transportation of photo-generated carriers.At the same time,it also increases its photoactive sites to improve the catalytic efficiency.Compared with 2D CTF,the hydrogen production efficiency of the two Pt-modified CTF nanomaterials has been significantly improved.Among them,the hydrogen production efficiency of 3D Pt@CTF under visible light irradiation（λ>420nm）reached 1074.54μmol g^-1h^-1.The catalyst can maintain stable and efficient photoactivity in the 40-hour cycle test.This is due to the formation of Pt-N bonds in3D Pt@CTF,which makes 3D Pt@CTF shorten the electron transmission distance to a certain extent.Conducive to the separation of electrons and holes,so as to have efficient hydrogen production performance.