The Research Of Preparation And Catalytic Properties Of Gold Rods And Their Composite Materials

Due to its unique catalytic properties,chemical stability and non-toxicity,gold nanoparticles have been widely used in organic chemistry catalysis and electrochemical catalysis.However,it's easy to form aggregates for gold nanoparticles and it's necessary to further improve the catalytic properties of the materials.In the present thesis,we have designed a method to prepare the porous gold rods coated with TiO₂ and gold-nanoparticles rods with Pt based on porous gold rods and gold-nanoparticles rods.And then,these composite materials were applied to catalyze the reduction of 4-nitrophenol and electrooxidation of methanol.There are two main contents included in this thesis:1.Study of co-template synthesis of hollow nanoporous gold rods and TiO₂-coated gold rods for heterogeneous catalysis by using bacteria and polystyrene spheres as the templates.We have synthesized nanoporous gold rods and TiO₂-coated gold rods and studied the effects of different pore sizes,composition ratios and crystal form on catalytic properties.It was found that nanoporous gold rods with 5.3% anatase TiO₂ content have the best catalytic performance,which was synthesized under the condition when the diameter of polystyrene spheres was 110 nm,the mole ratio of H₂O to Tetraethoxysilane was 1:4,the annealed temperature was 450 ?,the annealed time was 2h,the ratio of ethanol to sol was 1:2 and the time of synthesis was 16 h.2.Study of template synthesis of gold-nanoparticles rods and Pt-coated gold-nanoparticles rods for catalyzing electrooxidation of methanol.We have prepared gold-nanoparticles rods and Pt-coated gold-nanoparticles rods.And also,we controlled the Pt content through changing the dosage of the gold-nanoparticles rods in the process of synthesis.It was found that the composite materials would have the best catalytic properties with 2.2% Pt when the dosage of the gold-nanoparticles rods was 300 mL.