For Catalytic Organic Synthesis Reaction Under Visible Light The Preparation Of Composite Polyphase Semiconductor Photocatalyst And Its Performance

In recent years,scientists are now taking a alternative energy found to replace fossil energy.Some semiconductors have attracted extensive attention from scientists due to they can transform solar energy to chemical energy.They have been widely used in fields such as degradation and electrolysis,but catalytic organic synthesis has not been studied.However,some organics,such as benzaldehyde,benzoic acid,and imine,play a decisive role in chemistry.Therefore,it is very significant then we can invent a kind a photocatalyst to catalytic synthesize large amounts of organic under a mind condition.Although some semiconductors have excellent optical properties,there are also have disadvantage.It is also a subject of this study to optimize semiconductors by some mothods.The visible-light photocatalytic performance on the series of heterostructured Ag/Pd/g-C₃N₄ and Pt/?-Bi₂O₃/Bi₂O₂CO₃ was investigated,the catalysts were prepared by using the NaBH₄ reduction and calcination method.Different characterization techniques,including SEM,TEM,XRD,UV-vis,XPS,FL and BET,were employed to investigate the morphology and optical properties of the as-prepared samples.The results indicated that the Ag,Pd nanoparticles were deposited in the g-C₃N₄ which had a sheet structure,and the Pt nanoparticles were deposited in the?-Bi₂O₃/Bi₂O₂CO₃which had a microsphere structure.The low-cost photocatalyst provided a synergistic photocatalytic activity through an efficient electron transfer process and can retard the recombination of electrons-holes.Then,the amination reaction and the oxidation reaction of benzyl alcohol were studied to verify the photocatalytic activity.The results showed that the activity of the catalysts Ag/Pd/g-C₃N₄?2wt%,1:1?and Pt/?-Bi₂O₃/Bi₂O₂CO₃?3wt%?were the highest.At the same time,the reaction was optimized by changing solvent and alkali and the alkali's dosage.Under the optimal reaction conditions,the derivatives,the light intensity and the wavelength were explored to test how they influenced the reaction.A possible photocatalytic mechanism for the synthesis of imine from benzyl alcohol and aniline and the oxidation of benzyl alcohol over Ag/Pd/g-C₃N₄?2wt%,1:1?and Pt/?-Bi₂O₃/Bi₂O₂CO₃?3wt%?were proposed.