Design And Performance Of Catalytic Materials Based On Energy Conversion

We are committed to the preparation of photocatalytic materials with high energy conversion performance and storage performance in order to alleviate the problem of energy shortage and environmental pollution.This paper mainly studies two aspects.One is the study of the photocatalytic nitrogen fixation performance of Bi loaded g-C₃N₄,the other is the study electrocatalytic performance of MoO₃.(1)Bi nanoparticles loaded g-C₃N₄ nanosheets(Bi/CN)are successfully prepared by a simple method,and the photocatalytic reduction of N₂ is studied.The specific surface area of Bi/CN increased significantly after Bi loading,which provided more N₂ adsorption sites.Due to the near-infrared response of Bi and its SPR effect in the visible light range,the range of light absorption range and the capacity of light absorption of Bi/CN are greatly increased,and the electron-hole recombination efficiency is reduced,thus improving the photocatalytic efficiency.Therefore,Bi-CN exhibits excellent N₂ reduction ability under visible light irradiation,in which the NH₃ yield of 30-Bi/CN is as high as 1025?mol L^-1g^-1h^-1,which is190%higher than that of CN(359?mol L^-1g^-1h^-1).The density functional theory(DFT)calculation shows that Bi-CN has a strong adsorption capacity for N₂,which is also conducive to the reduction of N₂.In addition,the degradation rate of 30-Bi/CN is 2.25 times higher than that of CN,indicating that Bi-CN has significant potential in photocatalytic reduction of nitrogen and photocatalytic degradation of dyes.(2)In this part,the electrocatalytic performances of h-MoO₃ and?-MoO₃ are mainly investigated in 1M KOH aqueous electrolyte solution.It is found that at 450 m V,the anodic current density(99.4 m A cm^-2)of?-MoO₃is 1.8 times higher than that of h-MoO₃(34.87 m A cm^-2).The higher OER activity is mainly due to the Jahn-Teller distortion of?-MoO₃,leading to the Lewis acid sites on the material surface,the generated Lewis acid sites promote the adsorption and activation of water molecules.The high electrochemical surface active area and strong oxidation capacity are also another important reason for the higher electrocatalytic performance of?-MoO₃ than that of h-MoO₃.Moreover,methylene blue(MB)molecules and urea are added into the electrolyte solution to further improve the electrocatalytic activity of?-MoO₃ and h-MoO₃,mainly in the form of lower initial overpotential and higher current density.More importantly,the addition of MB into the electrolyte can not only promote the electrocatalytic hydrogen production efficiency,but also effectively degrade MB,with degradation efficiency reaching 80%.