Application Of Two-dimensional Nanosheet In The Concerted Reaction Of Photocatalysis And Organocatalysis & Nitro-Mannich Reaction

In recent decades,photocatalysis has been a hot issue because of its high efficiency,environmental friendship and energy conservation.In more recent years,photocatalytic synthesis has widened the research of enantioselective synthesis to a large degree.However,the utilization of usually used semiconductor photocatalyst is restricted owing to its disadvantages,such as the recombination of photo-induced electron-hole pairs and the agglomeration of nanoparticles.Therefore,in this study,the two-dimensional?2D?nanomaterials,graphene and single or few layer NbSe₂?SOF-NbSe₂?,were used as the support of the semiconductor in photocatalytic synthesis to solve the aforementioned problems.The main results obtained are as follows:?1?The SOF-NbSe₂ exfoliated by lithium intercalation and PbBiO₂ Br nanoparticles were mingled in CH3 CN solution to synthesize PbBiO₂Br-SOF-NbSe₂ composite photocatalyst.The as-prepared sample was characterized by Transmission Electron Microscopy?TEM?,Scanning Electron Microscopy?SEM?,X-Ray Diffraction?XRD?,UV-vis spectroscopy,Electrochemical Impedance Spectra?EIS?,etc.It was found from the experiment of the visible light-driven asymmetric alkylation of aldehyde that the introduction of a small amount of NbSe₂?0.5 wt %?to the PbBiO₂ Br semiconductor could result in 50% increase in the yield of the final product.This study shows that NbSe₂ nanosheets can be used as an efficient support to suppress the recombination of photo-induced electrons and holes and contribute to the enhanced photocatalytic performances of semiconductors in the visble light-driven catalysis.?2?The PbBiO₂ Br nanoparticles were successfully dispersed on reduced graphene oxide?rGO?by one step hydrothermal method.The obtained PbBiO₂Br-rGO nanocomposite was characterized by TEM,XRD,UV-vis spectroscopy,etc.The PbBiO₂Br-rGO nanocomposite photocatalyst was demonstrated to show excellent activities in Nitro-Manich reaction.The optimal mass ratio of rGO/PbBiO₂ Br was found to be 2%,which could result in a 50% increase in the final product.This study shows that the semiconductor nanocomposite based on rGO support can show excellent performances in photocatalytic organic synthesis.